Background of the Invention
1. Field of the Invention
[0001] The present invention is related to an information display apparatus and an information
display method. More specifically, the present invention is directed to display both
a traveling condition in front of the own vehicle and a navigation information in
a superimposing mode.
[0002] Document
EP 1 300 717 describes an overhead view display system for a vehicle for indicating the existence
of and relative distances to other vehicles.
2. Description of the Related Art
[0003] In recent years, specific attentions have been paid to an information display apparatus
in which a traveling condition in front of the own vehicle is displayed on a display
unit mounted on the own vehicle in combination with a navigation information. For
instance,
Japanese Laid-open patent Application No. Hei-11-250396 (hereinafter referred as a patent publication 1) discloses a display apparatus for
vehicle in which an infrared partial image, corresponding to a region where the own
vehicle is traveled, in an infrared image photographed by using an infrared camera,
is displayed on a display screen so that the partial infrared image is superimposed
on a map image. In accordance with the patent publication 1, since such an infrared
partial image, from which an image portion having a low necessity has been cut, is
superimposed on the map image, sorts and dimensions of obstructions can be readily
recognized, and thus, recognizing characteristics of targets can be improved. On the
other hand,
Japanese Laid-open patent Application No 2002-46504 (hereinafter referred as a patent publication 2) discloses a cruising control apparatus
having an information display apparatus by which positional information as to a peripheral-traveling
vehicle and a following vehicle with respect to the own vehicle are superimposed on
a road shape produced from a map information, and then, the resulting image is displayed
on the display screen. In accordance with the patent publication 2, a mark indicative
of the own vehicle position, a mark representative of a position of the following
vehicle, and a mark indicative of a position of the peripheral-traveling vehicle other
than the following vehicle are displayed so that colors and patterns of these marks
are changed with respect to each other and these marks are superimposed on a road
image.
[0004] However, according to the patent publication 1, the infrared image is merely displayed,
and the user recognizes the obstructions from the infrared image which is dynamically
changed. Also, according to the patent publication 2, although the own vehicle, the
following vehicle, and the peripheral-traveling vehicle are displayed in different
display modes, other necessary information than the above-described display information
cannot be acquired.
[0005] Further, according to the methods disclosed in the patent publication 1 and patent
publication 2, there are some possibilities that a color of a target actually located
in front of the own vehicle does not correspond to a color of a target displayed on
the display apparatus. As a result, a coloration difference between both these colors
may possibly give a sense of incongruity to a user. These information display apparatus
have been conducted as apparatus designed so as to achieve safety and comfortable
drives. User friendly degrees of these apparatus may constitute added values, and
thus, may conduct purchasing desires of users. As a consequence, in these sorts of
apparatus, higher user friendly functions and unique functions are required.
Summary of the Invention
[0006] An object of the present invention is to provide an information display apparatus
and an information display method which displays both a navigation information and
a traveling condition in a superimposing mode, and which can provide a improved user
friendly characteristic of the information display apparatus.
[0007] To solve the above-described problem, an information display apparatus according
to a first aspect of the present invention, comprises:
a preview sensor for detecting a traveling condition in front of own vehicle;
a navigation system for outputting a navigation information in response to a traveling
operation of the own vehicle;
a recognizing unit for recognizing a plurality of targets located in front of the
own vehicle based upon a detection result from the preview sensor, and for classifying
the recognized targets by sorts to which the plural targets belong;
a control unit for determining information to be displayed based upon both the targets
recognized by the recognizing unit and the navigation information; and
a display device for displaying the determined information under control of the control
unit,
wherein the control unit controls the display device so that both symbols indicative
of the recognized targets and the navigation information are displayed in a superimposing
manner, and also, controls the display device so that the plural symbols are displayed
by employing a plurality of different display colors corresponding to the sorts to
which the respective targets belong.
[0008] In this case, in the first aspect of the present invention, the recognizing unit
preferably classifies the recognized target by at least any one of an automobile,
a two-wheeled vehicle, a pedestrian, and an obstruction.
[0009] Also, an information display method according to a second aspect of the present invention,
comprises:
a first step of recognizing a plurality of targets located in front of own vehicle
based upon a detection result obtained by detecting a traveling condition in front
of the own vehicle , and classifying the recognized targets by sorts to which the
plural targets belong;
a second step of acquiring a navigation information in response to a traveling operation
of the own vehicle; and
a third step of determining information to be displayed based upon both the targets
recognized by the first step and the navigation information acquired by the second
step, and displaying the determined information,
wherein the third step includes displaying both symbols indicative of the recognized
targets and the navigation information in a superimposing manner, and displaying the
plural symbols by employing a plurality of different display colors corresponding
to the sorts to which the respective targets belong.
[0010] In this case, in the second aspect of the present invention, the first step preferably
includes classifying the recognized target by at least any one of an automobile, a
two-wheeled vehicle, a pedestrian, and an obstruction.
[0011] Also, an information display apparatus according to a third aspect of the present
invention, comprises:
a preview sensor for detecting a traveling condition in front of own vehicle;
a navigation system for outputting a navigation information in response to a traveling
operation of the own vehicle;
a recognizing unit for recognizing a plurality of targets located in front of the
own vehicle based upon a detection result from the preview sensor, and for calculating
dangerous degrees of the recognized targets with respect to the own vehicle;
a control unit for determining information to be displayed based upon both the targets
recognized by the recognizing unit and the navigation information; and
a display device for displaying the determined information under control of the control
unit,
wherein the control unit controls the display device so that both symbols indicative
of the recognized targets and the navigation information are displayed in a superimposing
manner, and also, controls the display device so that the plural symbols are displayed
by employing a plurality of different display colors corresponding to the dangerous
degrees.
[0012] Furthermore, an information display method according to a fourth aspect of the present
invention, comprises:
a first step of recognizing a plurality of targets located in front of own vehicle
based upon a detection result obtained by detecting a traveling condition in front
of the own vehicle, and calculating dangerous degrees of the recognized targets with
respect to the own vehicle;
a second step of acquiring a navigation information in response to a traveling operation
of the own vehicle; and
a third step of determining information to be displayed based upon both the targets
recognized by the first step and the navigation information acquired by the second
step, and displaying the determined information,
wherein the third step includes displaying both symbols indicative of the recognized
targets and the navigation information in a superimposing manner, and displaying the
plural symbols by employing a plurality of different display colors corresponding
to the dangerous degrees.
[0013] In this case, in either the third aspect or the fourth aspect of the present invention,
the display colors are preferably set to three, or more different colors in response
to the dangerous degrees.
[0014] In accordance with the present invention, the targets located in front of the own
vehicle may be recognized based upon the detection result from the preview sensor.
Then, the symbols indicative of the targets and the navigation information are displayed
in the superimposing mode. In this case, the display device is controlled so that
the symbols to be displayed are represented in the different display colors in response
to the recognized targets. As a consequence, since the differences in the targets
can be judged based upon the coloration, the visual recognizable characteristic of
the user can be improved. As a result, the user convenient characteristic can be improved.
[0015] Further, to solve the above-described problem, an information display apparatus according
to a fifth aspect of the present invention, comprises:
a camera for outputting a color image by photographing a scene in front of own vehicle;
a navigation system for outputting a navigation information in response to a traveling
operation of the own vehicle;
a recognizing unit for recognizing a target located in front of the own vehicle based
upon the outputted color image, and for outputting the color information of the recognized
target;
a control unit for determining information to be displayed based upon both the targets
recognized by the recognizing unit and the navigation information; and
a display device for displaying the determined information under control of the control
unit,
wherein the control unit controls the display device so that a symbol indicative of
the recognized target and the navigation information are displayed in a superimposing
manner, and controls the display device so that the symbol is displayed by employing
a display color which corresponds to the color information of the target.
[0016] In the information display apparatus of the fifth aspect of the present invention,
the information display apparatus, preferably further comprises:
a sensor for outputting a distance data which represents a two-dimensional distribution
of a distance in front of the own vehicle,
wherein the recognizing unit recognizes a position of the target based upon the distance
data; and
the control unit controls the display device so that the symbol is displayed in correspondence
with the position of the target in a real space based upon the position of the target
recognized by the recognizing.
[0017] Also, in the information display apparatus of the fifth aspect of the present invention,
the camera preferably comprise a first camera for outputting the color image by photographing
the scene in front of the own vehicle, and a second camera which functions as a stereoscopic
camera operated in conjunction with the first camera; and
the sensor outputs the distance data by executing a stereoscopic matching operation
based upon both the color image outputted from the first camera and the color image
outputted from the second camera.
[0018] Furthermore, in the information display apparatus of the fifth aspect of the present
invention, in the case that the recognizing unit judges such a traveling condition
that the outputted color information of the target is different from an actual color
of the target, the recognizing unit may specify the color information of the target
based upon the color information of the target which has been outputted in the preceding
time; and
the control unit may control the display device so that the symbol is displayed by
employing a display color corresponding to the specified color information.
[0019] Also, in the information display apparatus of the fifth aspect of the present invention,
the control unit may control the display device so that as to a target, the color
information of which is not outputted from the recognizing unit, the symbol indicative
of the target is displayed by employing a predetermined display color which has been
previously set.
[0020] Also, an information display method according to a sixth aspect of the present invention,
comprises:
a first step of recognizing a target located in front of own vehicle based upon a
color image acquired by photographing a scene in front of the own vehicle, and producing
a color information of the recognized target;
a second step of acquiring a navigation information in response to a traveling operation
of the own vehicle; and
a third step of displaying a symbol indicative of the recognized target and the navigation
information in a superimposing manner so that the symbol is displayed by employing
a display color corresponding to the produced color information of the target.
[0021] In the information display method of the sixth aspect of the present invention, the
information display method may further comprise a fourth step of recognizing a position
of the target based upon a distance data indicative of a two-dimensional distribution
of a distance in front of the own vehicle . In this case, the third step may be displaying
the symbol in correspondence with a position of the target in a real space based upon
the position of the recognized target.
[0022] Also, in the information display method of the sixth aspect of the present invention,
preferably, the first step includes a step of, when a judgment is made of such a traveling
condition that the produced color information of the target is different from an actual
color of the target, specifying a color information of the target based upon the color
information of the target which has been outputted in the preceding time; and
the third step includes a step of controlling the display device so that the symbol
is displayed by employing a display color corresponding to the specified color information.
[0023] Further, in the information display method of the sixth aspect of the present invention,
preferably, the third step includes a step of controlling the display device so that
with respect to a target whose color information is not produced, the symbol indicative
of the target is displayed by employing a predetermined display color which has been
previously set.
[0024] In accordance with the present invention, the target located in front of the own
vehicle is recognized based upon the color image acquired by photographing the forward
scene of the own vehicle, and also, the color information of this target is outputted.
Then, the display device is controlled so that the symbol indicative of this recognized
target and the navigation information are displayed in the superimposing mode . In
this case, the symbol to be displayed is displayed by employing such a display color
corresponding to the outputted color information of the target. As a result, the traveling
condition which is actually recognized by the car driver may correspond to the symbols
displayed on the display device in the coloration, so that the colorative incongruity
feelings occurred between the recognized traveling condition and the displayed symbols
can be reduced. As a consequence, since the user visual recognizable characteristic
can be improved, the user friendly aspect can be improved.
Brief Description of the Drawings
[0025]
Fig. 1 is a block diagram for showing an entire arrangement of an information display
apparatus according to a first embodiment of the present invention;
Fig. 2 is a flow chart for showing a sequence of an information display process according
to the first embodiment;
Figs. 3A-3D are schematic diagrams for showing examples of display symbols;
Fig. 4 is an explanatory diagram for showing a display condition of the display apparatus;
Fig. 5 is an explanatory diagram for showing another display condition of the display
apparatus;
Fig. 6 is a block diagram for showing an entire arrangement of an information display
apparatus according to a third embodiment of the present invention;
Fig. 7 is a flow chart for showing a sequence of an information display process according
to the third embodiment;
Fig. 8 is an explanatory diagram for showing a display condition of the display apparatus;
and
Fig. 9 is a schematic diagram for showing a display condition in front of the own
vehicle.
Detailed Description of the Invention
(First Embodiment)
[0026] Fig. 1 is a block diagram for showing an entire arrangement of an information display
apparatus 1 according to a first embodiment of the present invention. A preview sensor
2 senses a traveling condition in front of the own vehicle. As the preview sensor
2, a stereoscopic image processing apparatus may be employed. The stereoscopic image
processing apparatus is well known in this technical field, and is arranged by a stereoscopic
camera and an image processing system.
[0027] The stereoscopic camera which photographs a forward scene of the own vehicle is mounted
in the vicinity of, for example, a room mirror of the own vehicle. The stereoscopic
camera is constituted by one pair of a main camera 20 and a sub-camera 21. An image
sensor (for instance, either CCD sensor or CMOS sensor etc.) is built in each of these
cameras 20 and 21. The main camera 20 photographs a reference image and the sub-camera
21 photographs a comparison image, which are required so as to perform a stereoscopic
image processing. Under such a condition that the operation of the main camera 20
is synchronized with the operation of the sub-camera 21, respective analog images
outputted from the main camera 20 and the sub-camera 21 are converted into digital
images having a predetermined luminance gradation (for instance, gray scale of 256
gradation values) by A/D converters 22 and 23, respectively.
[0028] One pair of digital image data are processed by an image correcting unit 24 so that
luminance corrections are performed, geometrical transformations of images are performed,
and so on. Under normal condition, since errors may occur as to mounting positions
of the one-paired cameras 20 and 21 to some extent, shifts caused by these positional
errors are produced in each of reference and composition images. In order to correct
this image shift, an affine transformation and the like are used, so that geometrical
transformations are carried out, namely, an image is rotated, and is moved in a parallel
manner.
[0029] After the digital image data have been processed in accordance with such an image
processing, a reference image data is obtained from the main camera 20, and a comparison
image data is obtained from the sub-camera 21. These reference and comparison image
data correspond to a set of luminance values (0 to 255) of respective pixels. In this
case, an image plane which is defined by image data is represented by an i-j coordinate
system. While a lower left corner of the image is assumed as an origin, a horizontal
direction is assumed as an i-coordinate axis whereas a vertical direction is assumed
as a j-coordinate axis. Stereoscopic image data equivalent to 1 frame is outputted
to a stereoscopic image processing unit 25 provided at a post stage of the image correcting
unit 24, and also, is stored in an image data memory 26.
[0030] The stereoscopic image processing unit 25 calculates a distance data based upon both
the reference image data and the comparison image data, while the distance data is
related to a photograph image equivalent to 1 frame. In this connection, the term
"distance data" implies set of parallaxes which are calculated every small region
in an image plane which is defined by image data, while each of these parallaxes corresponds
to a position (i, j) on the image plane. One of the parallaxes is calculated with
respect to each pixel block having a predetermined area (for instance, 4 X 4 pixels)
which constitutes a portion of the reference image.
[0031] In the case that a parallax related to a certain pixel block (correlated source)
is calculated, a region (correlated destination) having a correlation with a luminance
characteristic of this pixel block is specified in the comparison image. Distances
defined from the cameras 20 and 21 to a target appear as shift amounts along the horizontal
direction between the reference image and the comparison image. As a consequence,
in such a case that a correlated source is searched in the comparison image, a pixel
on the same horizontal line (epipolar line) as a "j" coordinate of a pixel block which
constitutes a correlated source may be searched. While the stereoscopic image processing
unit 25 shifts pixels on the epipolar line one pixel by one pixel within a predetermined
searching range which is set by using the "i" coordinate of the correlated source
as a reference, the stereoscopic image processing unit 25 sequentially evaluates a
correlation between the correlated source and a candidate of the correlated destination
(namely, stereoscopic-matching). Then, in principle, a shift amount of such a correlated
destination (any one of candidates of correlated destinations), the correlation of
which may be judged as the highest correlation along the horizontal direction, is
defined as a parallax of this pixel block. It should be understood that since a hardware
structure of the stereoscopic image processing unit 25 is described in
Japanese Laid-open patent Application No. Hei-5-114099, this hardware structure may be observed, if necessary. The distance data which has
been calculated by executing the above-explained process, namely, a set of parallaxes
corresponding to the position (i, j) on the image is stored in a distance data memory
27.
[0032] A microcomputer 3 is constituted by a CPU, a ROM, a RAM, an input/output interface,
and the like. When functions of the microcomputer-3 are grasped, this microcomputer
3 contains both a recognizing unit 4 and a control unit 5. The recognizing unit 4
recognizes targets located in front of the own vehicle based upon a detection result
from the preview sensor 2, and also, classifies the recognized targets based upon
sorts to which the targets belong. Targets which should be recognized by the recognizing
unit 4 are typically three-dimensional objects. In the first embodiment, these targets
correspond to 4 sorts of such three-dimensional objects as an automobile, a two-wheeled
vehicle, a pedestrian, and an obstruction (for example, falling object on road, pylon
used in road construction, tree planted on road side, etc.). The control unit 5 determines
information which should be displayed with respect to the display device 6 based upon
the targets recognized by the recognizing unit 4 and the navigation information. Then,
the control unit 5 controls the display device 6 so as to display symbols indicative
of the recognized targets and the navigation information in a superimposing mode.
To this end, the symbols indicative of the targets (in this embodiment, automobile,
two-wheeled vehicle, pedestrian, and obstruction) have been stored in the ROM of the
microcomputer 3 in the form of data having predetermined formats (for instance, image
and wire frame model). Then, the symbols indicative of these targets are displayed
by employing a plurality of different display colors which correspond to the sorts
to which the respective targets belong. Also, in the case that the recognizing unit
4 judges that a warning is required for a car driver based upon the recognition result
of the targets, the recognizing unit 4 operates the display device 6 and the speaker
7, so that the recognizing unit 4 may cause the car driver to pay his attention. Further,
the recognizing unit 4 may control the control device 8 so as to perform such a vehicle
control operation as a shift down control, a braking control and so on.
[0033] In this case, a navigation information is such an information which is required to
display a present position of the own vehicle and a scheduled route of the own vehicle
in combination with map information. The navigation information can be acquired from
a navigation system 9 which is well known in this technical field. Although this navigation
system 9 is not clearly illustrated in Fig. 1, the navigation system 9 is mainly arranged
by a vehicle speed sensor, a gyroscope, a GPS receiver, a map data input unit, and
a navigation control unit. The vehicle speed sensor corresponds to a sensor for sensing
a speed of a vehicle. The gyroscope detects an azimuth angle change amount of the
vehicle based upon an angular velocity of rotation motion applied to the vehicle.
The GPS receiver receives electromagnetic waves via an antenna, which are transmitted
from GPS-purpose satellites, and then, detects a positioning information such as a
position, azimuth (traveling direction) , and the like of the vehicle. The map data
input unit corresponds to an apparatus which enters data as to a map information (will
be referred to as "map data" hereinafter) into the navigation system 9. The map data
has been stored in a recording medium which is generally known as a CD-ROM and a DVD.
The navigation control unit calculates a present position of the vehicle based upon
either the positioning information acquired from the GPS receiver or both a travel
distance of the vehicle in response to a vehicle speed and an azimuth change amount
of the vehicle. Both the present position calculated by the navigation control unit
and map data corresponding to this present position are outputted as navigation information
with respect to the control unit 5.
[0034] Fig. 2 is a flow chart for describing a sequence of an information display process
according to the first embodiment. A routine indicated in this flow chart is called
every time a preselected time interval has passed, and then, the called routine is
executed by the microcomputer 3. In a step 1, a detection result obtained in the preview
sensor 2, namely information required so as to recognize a traveling condition in
front of the own vehicle (namely, forward traveling condition) is acquired. In the
stereoscopic image processing apparatus functioning as the preview sensor 2, in the
step 1, the distance data which has been stored in the distance data memory 27 is
read. Also, the image data which has been stored in the image data memory 26 is read,
if necessary.
[0035] In a step 2, three-dimensional objects are recognized which are located in front
of the own vehicle. When the three-dimensional objects are recognized, first of all,
noise contained in the distance data is removed by a group filtering process. In other
words, parallaxes which may be considered as low reliability are removed. A parallax
which is caused by mismatching effects due to adverse influences such as noise is
largely different from a value of a peripheral parallax, and owns such a characteristic
that an area of a group having a value equivalent to this parallax becomes relatively
small. As a consequence, as to parallaxes which are calculated as to the respective
pixel blocks, change amounts with respect to parallaxes in pixel blocks which are
located adjacent to each other along upper/lower directions, and right/left directions,
which are present within a predetermined threshold value, are grouped. Then, dimension
of areas of groups are detected, and such a group having a larger area than a predetermined
dimension (for example, 2 pixel blocks) is judged as an effective group. On the other
hand, distance data (isolated distance data) belonging to such a group having an area
smaller than, or equal to the predetermined dimension is removed from the distance
data, since it is so judged that reliability of the calculated parallax is low.
[0036] Next, based upon both the parallax extracted by the group filtering process and the
coordinate position on the image plane, which corresponds to this extracted parallax,
a position on a real space is calculated by employing the coordinate transforming
formula which is well known in this field. Then, since the calculated position on
the real space is compared with the position of the road plane, such a parallax located
above the road plane is extracted. In other words, a parallax equivalent to a three-dimensional
object (will be referred to as "three-dimensional object parallax" hereinafter) is
extracted. A position on the road surface may be specified by calculating a road model
which defines a road shape. The road model is expressed by linear equations both in
the horizontal direction and the vertical direction in the coordinate system of the
real space, and is calculated by setting a parameter of this linear equation to such
a value which is made coincident with the actual road shape. The recognizing unit
5 refers to the image data based upon such an acquired knowledge that a white lane
line drawn on a road surface owns a high luminance value as compared with that of
the road surface. Positions of right-sided white lane line and left-sided white lane
line may be specified by evaluating a luminance change along a width direction of
the road based upon this image data. Then, a position of a white lane line on the
real space is detected by employing distance data based upon the position of this
white lane line on the image plane. The road model is calculated so that the white
lane lines on the road are subdivided into a plurality of sections along the distance
direction, the right-sided white lane line and the left-sided white lane line in each
of the sub-divided sections are approximated by three-dimensional straight lines,
and then, these three-dimensional straight lines are coupled to each other in a folded
line shape.
[0037] Next, the distance data is segmented in a lattice shape, and a histogram related
to three-dimensional object parallaxes belonging to each of these sections is formed
every section of this lattice shape. This histogram represents a distribution of frequencies
of the three-dimensional parallaxes contained per unit section. In this histogram,
a frequency of a parallax indicative of a certain three-dimensional object becomes
high. As a result, in the formed histogram, since such a three-dimensional object
parallax whose frequency becomes larger than, or equal to a judgment value is detected,
this detected three-dimensional object parallel is detected as a candidate of such
a three-dimensional object which is located in front of the own vehicle. In this case,
a distance defined up to the candidate of the three-dimensional object is also calculated.
Next, in the adjoining sections, candidates of three-dimensional objects, the calculated
distances of which are in proximity to each other, are grouped, and then, each of
these groups is recognized as a three-dimensional object. As to the recognized three-dimensional
object, positions of right/left edge portions, a central position, a distance, and
the like are defined as parameters in correspondence therewith. It should be noted
that the concrete processing sequence in the group filter and the concrete processing
sequence of the three-dimensional object recognition are disclosed in
Japanese Laid-open patent Application No. Hei-10-285582, which may be taken into account, if necessary.
[0038] In a step 3, the recognized three-dimensional object is classified based upon a sort
to which this three-dimensional object belongs. The recognized three-dimensional object
is classified based upon, for example, conditions indicated in the below-mentioned
items (1) to (3):
- (1) whether or not a width of the recognized three-dimensional object along a lateral
direction is smaller than, or equal to a judgment value.
Among the recognized three-dimensional objects, since a width of an automobile along
the width direction thereof is wider than each of widths of other three-dimensional
objects (two-wheeled vehicle, pedestrian, and obstruction), the automobile may be
separated from other three-dimensional objects, while the lateral width of the three-dimensional
object is employed as a judgment reference. As a result, since a properly set judgment
value (for example, 1 meter) is employed, a sort of such a three-dimensional object
whose lateral width is larger than the judgment value may be classified as the automobile.
- (2) Whether or not a velocity "V" of a three-dimensional object is lower than, or
equal to a judgment value.
Among three-dimensional objects except for an automobile, since a velocity "V" of
a two-wheeled vehicle is higher than velocities of other three-dimensional objects
(pedestrian and objection), the two-wheeled vehicle may be separated from other three-dimensional
objects, while the velocity "V" of the three-dimensional object is used as a judgment
reference. As a consequence, since a properly set judgment value (for instance, 10
km/h) is employed, a sort of such a three-dimensional object whose velocity "V" is
higher than the judgment value may be classified as the two-wheeled vehicle. It should
also be understood that a velocity "V" of a three-dimension object may be calculated
based upon both a relative velocity "Vr" and a present velocity "V0" of the own vehicle,
while this relative velocity "Vr" is calculated in accordance with a present position
of this three-dimensional object and a position of this three-dimensional object before
predetermined time has passed.
- (3) Whether or not a velocity "V" is equal to 0.
Among three-dimensional objects except for both an automobile and a two-wheeled object,
since a velocity "V" of an obstruction is equal to 0, the obstruction may be separated
from a pedestrian, while the velocity V of the three-dimensional object is employed
as a judgment reference. As a consequence, a sort of such a three-dimensional object
whose velocity becomes equal to 0 may be classified by the obstruction.
[0039] Other than these three conditions, since heights of three-dimensional objects are
compared with each other, a pedestrian may be alternatively separated from an automobile.
Furthermore, such a three-dimensional object, the position of which in the real space
is located at the outer side than the position of the white lane line (road model),
may be alternatively classified by a pedestrian. Also, such a three-dimensional object
which is moved along the lateral direction may be alternatively classified by a pedestrian
who walks across a road.
[0040] In a step 4, a display process is carried out based upon the navigation information
and the recognized three-dimensional object. First, the control unit 5 determines
a symbol based upon the sort to which the recognized three-dimensional object belongs,
while the symbol is used so as to display this three-dimensional object on the display
device 6. Figs. 3A-3D are schematic diagrams for showing examples of symbols. In this
drawing, symbols used to display three-dimensional objects belonging to the respective
sorts are represented, and each of these symbols is made of a design for designing
the relevant sort. In the drawing, Fig. 3A shows a symbol used to display a three-dimensional
object, the sort of which is classified by an "automobile"; Fig. 3B shows a symbol
used to display a three-dimensional object, the sort of which is classified by a "two-wheeled
vehicle." Also, Fig. 3C shows a symbol used to display a three-dimensional object,
the sort of which is classified by a "pedestrian"; and Fig. 3D shows a symbol used
to display a three-dimensional object, the sort of which is classified by an "obstruction."
[0041] For instance, in such a case that a sort of the three-dimensional object is classified
by a "two-wheeled vehicle", the control apparatus 5 controls the display device 6
so that the symbol indicated in Fig. 3B is displayed as the symbol indicative of this
three-dimensional object. It should be understood that in such a case that two, or
more pieces of three-dimensional objects which have been classified by the same sorts
are recognized, or in the case that two, or more pieces of three-dimensional objects
which have been classified by the different sorts from each other are recognized,
the control unit 5 controls the display device 6 so that the symbols corresponding
to the sorts of the respective recognized three-dimensional objects are represented.
[0042] Then, the control unit 5 controls the display device 6 so as to realize display modes
described in the below-mentioned items (1) and (2):
- (1) Both the symbol and the navigation information are displayed in a superimposing
mode.
In a three-dimensional object recognizing operation using the preview sensor 2, a
position of the three-dimensional object is represented by a coordinate system (in
this first embodiment, three-dimensional coordinate system) in which the position
of the own vehicle is set to a position of an origin thereof. Under such a circumstance,
while the present position of the own vehicle acquired from the navigation system
9 is employed as a reference position, the control unit 5 superimposes symbols corresponding
to the respective three-dimensional objects on the map data by considering the positions
of the respective three-dimensional objects. In this case, while the control unit
5 refers to a road model, the control unit 5 defines a road position on the road data
in correspondence with the positions of the three-dimensional objects by setting the
road model, so that the symbols can be displayed on more correct positions.
- (2) Symbols are displayed in predetermined display colors.
[0043] As to symbols displayed on map data, display colors have been previously set in correspondence
with sorts to which three-dimensional objects belong. In the first embodiment, in
view of such a point that weaklings in a traffic environment must be protected, a
red display color which becomes conspicuous in a color sense has been previously set
to such a symbol indicative of a pedestrian to which the highest attention should
be paid, and a yellow display color has been previously set to such a symbol indicative
of a two-wheeled vehicle to which the second highest attention should be paid. Also,
a blue display color has been previously set to a symbol representative of an automobile,
and a green display color has been previously set to a symbol representative of an
obstruction. As a result, when a symbol is displayed, the control unit 5 controls
the display device 6 so that this symbol is displayed by such a display color in correspondence
with a sort to which a three-dimensional object belongs.
[0044] Fig. 4 is an explanatory diagram for showing a display condition of the display device
6. In this drawing, in such a case that two automobiles are recognized, one two-wheeled
vehicle is recognized, and only one pedestrian is recognized, the map data is displayed
by employing a so-called "driver' s eye" manner, and symbols indicative of the respective
three-dimensional objects are displayed in such a case that these symbols are superimposed
on this map data. As previously explained, while the display colors have been previously
set to the symbols displayed on the display device 6, only symbols indicative of the
three-dimensional objects which are classified by the same sorts are displayed in
the same display colors.
[0045] Alternatively, as illustrated in this drawing, it should be understood that the control
unit 5 may control the display device 6 in order that the symbols are represented
by the perspective feelings other than the above-described conditions (1) and (2).
In this alternative case, the further a three-dimensional object is located far from
the own vehicle, the smaller a display size of a symbol thereof is decreased in response
to a distance from the recognized three-dimensional object symbol to the own vehicle.
Also, in such a case that a symbol which is displayed at a positionally far position
is overlapped with another symbol which is displayed at a position closer than the
above-described far position with respect to the own vehicle, the control unit 6 may
alternatively control the display device 6 so that the former symbol is displayed
on the side of the upper plane, as compared with the latter symbol. As a consequence,
since the far-located symbol is covered to be masked by the near-located symbol, the
visual recognizable characteristic of the symbols may be improved, and furthermore,
the positional front/rear relationship between these symbols may be represented.
[0046] As previously explained, in accordance with the first embodiment, a target (in the
first embodiment, three-dimensional object) which is located in front of the own vehicle
is recognized based upon the detection result obtained from the preview sensor 2.
Also, the recognized target is classified by a sort to which this three-dimensional
object belongs based upon the detection result obtained from the preview sensor 2.
Then, a symbol indicative of the recognized target and navigation information are
displayed in the superimposing mode. In this case, the display device 6 is controlled
so that the symbol to be displayed becomes such a display color corresponding to the
classified sort. As a result, since the difference in the sorts of the targets can
be recognized by way of the coloration, the visual recognizable characteristic by
the user (typically, car driver) can be improved. Also, since the display colors are
separately utilized in response to the degrees for conducting the attentions, the
orders of the three-dimensional objets to which the car driver should pay his attention
can be grasped from the coloration by way of the experimental manner. As a result,
since the user convenient characteristic can be improved by the functions which are
not realized in the prior art, the product attractive force can be improved in view
of the user friendly aspect.
[0047] It should also be understood that when the symbols corresponding to all of the recognized
three-dimensional objects are displayed, there is such a merit that the traveling
condition is displayed in detail. However, the amount of information displayed on
the screen is increased. In other words, such an information as a preceding-traveled
vehicle which is located far from the own vehicle is also displayed which has no direct
relationship with the driving operation. In view of such an idea for eliminating unnecessary
information, a plurality of three-dimensional objects which are located close to the
own vehicle may be alternatively selected, and then, only symbols corresponding to
these selected three-dimensional objects may be alternatively displayed. It should
also be noted that a selecting method may be alternatively determined so that a pedestrian
which must be protected at the highest safety degree is selected in a top priority.
Also, in the first embodiment, the three-dimensional objects have been classified
by the four sorts. Alternatively, these three-dimensional objects may be classified
by more precise sorts within a range which can be recognized by the preview sensor
2.
(Second Embodiment)
[0048] A different point as to an information display processing operation according to
a second embodiment of the present invention from that of the first embodiment is
given as follows: That is, display colors of symbols are set in response to dangerous
degrees (concretely speaking, collision possibility) of recognized three-dimensional
objects with respect to the own vehicle. As a result, in the second embodiment, as
to the recognized three-dimensional objects, dangerous grades "T" indicative of dangerous
degrees with respect to the own vehicle are furthermore calculated by the recognizing
unit 4. Then, the respective symbols representative of the recognized three-dimensional
objects are displayed by employing a plurality of different display colors corresponding
to the dangerous grades T of the three-dimensional objects.
[0049] Concretely speaking, first of all, similar to the process shown in steps 1 to 3 in
Fig. 2, based upon a detection result obtained from the preview sensor 2, three-dimensional
objects located in front of the own vehicle are recognized, and further, these recognized
three-dimensional objects are classified by sorts to which these three-dimensional
objects belong. Then, in this second embodiment, after the step 3, while the respective
recognized three-dimensional objects (targets) are handled as calculation objects,
dangerous grades "T" of the respective recognized three-dimensional objects are calculated.
This dangerous grade "T" may be calculated in a principal manner by employing, for
example, the below-mentioned formula 1:

[0050] In this formula 1, symbol "D" shows a distance (m) measured up to a target; symbol
"Vr" indicates a relative velocity between the own vehicle and the target; and symbol
"Ar" represents a relative acceleration between the own vehicle and the target. Also,
parameters "K1" to "K3" correspond to coefficients related to the respective variables
"D", "Vr", "Ar." It should be understood that these parameter K1 to K3 have been set
to proper values by previously executing an experiment and a simulation. For instance,
the formula 1 (dangerous grade T) to which these coefficients K1 to K3 have been set
indicates temporal spare until the own vehicle reaches a three-dimensional object.
In the second embodiment, the formula 1 implies that the larger a dangerous grade
T of a target becomes, the lower a dangerous degree of this target becomes (collision
possibility is low), whereas the smaller a dangerous grade T of a target becomes,
the higher a dangerous degree of this target becomes (collision possibility is high).
[0051] Then, similar to the process indicated in the step 4 of Fig. 2, a display process
is carried out based upon the navigation information and the three-dimensional objects
recognized by the recognizing unit 4. Concretely speaking, symbols to be displayed
are firstly determined based upon sorts to which these recognized three-dimensional
objects belong. The control unit 8 controls the display device 6 to display the symbols
and the navigation information in a superimposing manner. In this case, the display
colors of the symbols to be displayed have been previously set in correspondence with
the dangerous grades "T" which are calculated with respect to the corresponding three-dimensional
objects. Concretely speaking, as to a target (dangerous grade T ≤ first judgment value),
the dangerous grade T of which becomes smaller than, or equal to the first judgment
value, namely, the three-dimensional object whose dangerous degree is high, a display
color of this symbol has been set to a red color which becomes conspicuous in a color
sense. Also, as to another target (first judgment value < dangerous grade T ≤ second
judgment value), the dangerous grade T of which is larger than the first judgment
value and also is smaller than, or equal to a second judgment value larger than this
first judgment value, namely, the three-dimensional object whose dangerous degree
is relative high, a display color of this symbol has been set to a yellow color. Then,
a further object (second judgment value < dangerous grade T), the dangerous grade
T of which is larger than the second judgment value, namely, the three-dimensional
object whose dangerous degree is low, a display color of this symbol has been set
to a blue color.
[0052] Fig. 5 is an explanatory diagram for showing a display mode of the display device
6. This drawing exemplifies such a display mode in the case that a forward traveling
vehicle suddenly brakes wheels. As shown in this drawing, since the display colors
are separately used in correspondence with the dangerous grades "T", a symbol representing
the forward traveling vehicle is displayed in a red color, the dangerous degree of
which is high (namely, collision possibility is high) with respect to the own vehicle.
Then, a symbol indicative of a three-dimensional object, the dangerous degree of which
is low (namely, collision possibility is low) with respect to the own vehicle, is
displayed in either a yellow display color or a blue display color.
[0053] As previously described, in accordance with the second embodiment, both the symbols
indicative of the recognized targets and the navigation information are displayed
in the superimposing mode, and the display apparatus is controlled so that these symbols
are represented by the display colors in response to the dangerous degrees with respect
to the own vehicle. As a result, since the difference in the dangerous degrees of
the targets with respect to the own vehicle by way of the coloration, the visual recognizable
characteristic by the car driver can be improved. Also, since the display colors are
separately utilized in response to the degrees for conducting the car driver' s attentions,
the orders of the three-dimensional objects to which the car driver should pay his
attention can be grasped from the coloration by way of the experimental manner. As
a result, since the user convenient characteristic can be improved by the functions
which are not realized in the prior art, the product attractive force can be improved
in view of the user friendly aspect.
[0054] It should also be noted that although the symbols are displayed by employing the
three display colors in response to the dangerous grades "T" in this second embodiment,
these symbols may be alternatively displayed in a larger number of display colors
than the three display colors. In this alternative case, the dangerous degrees may
be recognized in a more precise range with respect to the car driver.
[0055] Also, the stereoscopic image processing apparatus has been employed as the preview
sensor 25 in both the first and second embodiments. Alternatively, other distance
detecting sensors such as a single-eye camera, a laser radar, and a millimeter wave
radar, which are well known in the technical field, may be employed in a sole mode,
or a combination mode. Even when the above-described alternative distance detecting
sensor is employed, a similar effect to that of the above-explained embodiments may
be achieved.
[0056] Also, in the first and second embodiments, such symbols have been employed, the designs
of which have been previously determined in response to the sorts of these three-dimensional
objects. Alternatively, one sort of symbol may be displayed irrespective of the sorts
of the three-dimensional objects. Also, based upon image data photographed by a stereoscopic
camera, such an image corresponding to the recognized three-dimensional object may
be displayed. Even in these alternative cases, since the display colors are made different
from each other, the same sort of three-dimensional objects (otherwise, dangerous
degree of three-dimensional objects) may be recognized based upon the coloration.
Furthermore, the present invention may be applied not only to the display manner such
as the driver's eye display manner, but also a bird's eye view display manner (for
example, bird view) and a plan view display manner.
(Third Embodiment)
[0057] Fig. 6 is a block diagram for representing an entire arrangement of an information
display apparatus 101 according to a third embodiment of the present invention. A
stereoscopic camera which photographs a forward scene of the own vehicle is mounted
in the vicinity of, for example, a room mirror of the own vehicle. The stereoscopic
camera is constituted by one pair of a main camera 102 and a sub-camera 103. The main
camera 102 photographs a reference image and the sub-camera 103 photographs a comparison
image, which are required so as to perform a stereoscopic image processing. While
separately operable image sensors (for example, 3-plate type color CCD) of red, green,
blue colors are built in each of the cameras 102 and 103, three primary color images
of a red image, a green image, a blue image are outputted from each of the main camera
102 and the sub-camera 103. As a result, color images outputted from one pair of the
cameras 102 and 103 are 6 sheets of color images in total. Under such a condition
that the operation of the main camera 102 is synchronized with the operation of the
sub-camera 103, respective analog images outputted from the main camera 102 and the
sub-camera 103 are converted into digital images having predetermined luminance gradation
(for instance, gray scale of 256 gradation values) by A/D converters 104 and 105,
respectively.
[0058] One pair of digitally-processed primary color images (6 primary color images in total)
are processed by an image correcting unit 106 so that luminance corrections are performed,
geometrical transformations of images are performed, and so on. Under normal condition,
since errors may occur as to mounting positions of the one-paired cameras 102 and
103 to some extent, shifts causedby these positional errors are produced in a right
image and a left image. In order to this image shift, an affine transformation and
the like are used, so that geometrical transformations are carried out, namely, an
image is rotated, and is moved in a parallel manner.
[0059] After the digital image data have been processed in accordance with such an image
processing, a reference image data corresponding to the three primary color images
is obtained from the main camera 102, and a comparison image data corresponding to
the three primary color images is obtained from the sub-camera 103. These reference
image data and comparison image data correspond to a set of luminance values (0 to
255) of respective pixels. In this case, an image plane which is defined by image
data is represented by an i-j coordinate system. While a lower left corner of this
image is assumed as an origin, a horizontal direction is assumed as an i-coordinate
axis whereas a vertical direction is assumed as a j-coordinate axis. Both reference
image data and comparison image data equivalent to 1 frame are outputted to a stereoscopic
image processing unit 107 provided at a post stage of the image correcting unit 106,
and also, are stored in an image data memory 109.
[0060] The stereoscopic image processing unit 107 calculates a distance data based upon
both the reference image data and the comparison image data, while the distance data
is related to a photograph image equivalent to 1 frame. In this connection, the term
"distance data" implies set of parallaxes which are calculated every small region
in an image plane which is defined by image data, while each of these parallaxes corresponds
to a position (i, j) on the image plane. One of the parallaxes is calculated with
respect to each pixel block having a predetermined area (for instance, 4 X 4 pixels)
which constitutes a portion of the reference image. In the third embodiment in which
the three primary color images are outputted from each of the cameras 102 and 103,
this stereoscopic matching operation is separately carried out every the same primary
color image.
[0061] In the case that a parallax related to a certain pixel block (correlated source)
is calculated, a region (correlated destination) having a correlation with a luminance
characteristic of this pixel block is specified in the comparison image. Distances
defined from the cameras 102 and 103 to a target appear as shift amounts along the
horizontal direction between the reference image and the comparison image. As a consequence,
in such a case that a correlated source is searched in the comparison image, a pixel
on the same horizontal line (epipolar line) as a "j" coordinate of a pixel block which
constitutes a correlated source may be searched. While the stereoscopic image processing
unit 125 shifts pixels on the epipolar line one pixel by one pixel within a predetermined
searching range which is set by using the "i" coordinate of the correlated source
as a reference, the stereoscopic image processing unit 125 sequentially evaluates
a correlation between the correlated source and a candidate of the correlated destination
(namely, stereoscopic-matching). Then, in principle, a shift amount of such a correlated
destination (any one of candidates of correlated destinations), the correlation of
which may be judged as the highest correlation along the horizontal direction is defined
as a parallax of this pixel block. In other words, distance data corresponds to a
two-dimensional distribution of a distance in front of the own vehicle. Then, the
stereoscopic image processing unit 107 performs a stereoscopic matching operation
between the same primary color images, and then, outputs the stereoscopically matched
primary color image data to a merging process unit 108 provided at a post stage of
this stereoscopic image processing unit 107. As a result, with respect to one pixel
block in the reference image, three parallaxes (will be solely referred to as "primary
color parallax" hereinafter) are calculated.
[0062] The merging process unit 108 merges three primary color parallaxes which have been
calculated as to a certain pixel block so as to calculate a unified parallax "Ni"
related to this certain pixel block. In order to merge the primary color parallaxes,
multiply/summation calculations are carried out based upon parameters (concretely
speaking, weight coefficients of respective colors) which are obtained from a detection
subject selecting unit 108a. A set of the parallaxes "Ni" which have been acquired
in the above-described manner and are equivalent to 1 frame is stored as distance
data into a distance data memory 110. It should also be noted that since both detailed
system structures and detailed system process operations of both the merging process
unit 8 and the detection subject selecting unit 8a are described in
Japanese Patent Application No. 2001-343801 which has already been filed the Applicant, contents thereof may be read, if necessary.
[0063] A microcomputer 111 is constituted by a CPU, a ROM, a RAM, an input/output interface,
and the like. When functions of the microcomputer 111 are grasped, this microcomputer
111 contains both a recognizing unit 112 and a control unit 113. The recognizing unit
112 recognizes targets located in front of the own vehicle based upon the primary
color image data stored in the image data memory 109, and also, produces color information
of the recognized targets. Targets which should be recognized by the recognizing unit
112 are typically three-dimensional objects. In the third embodiment, these targets
correspond to an automobile, a two-wheeled vehicle, a pedestrian, and so on. Both
the information of the targets recognized by the recognizing unit 112 and the color
information produced by the recognizing unit 112 are outputted with respect to the
control unit 113. The control unit 113 controls a display device 115 provided at a
post stage of the control unit 113 so that symbols indicative of the targets recognized
by the recognizing unit 112 are displayed by being superimposed on the navigation
information. In this case, the symbols corresponding to the targets are displayed
by using display colors which correspond to the color information of the outputted
targets.
[0064] In this case, a navigation information is such an information which is required to
display a present position of the own vehicle and a scheduled route of the own vehicle
in combination with map information on the display device 115, and the navigation
information can be acquired from a navigation system 114 which is well known in this
technical field. Although this navigation system 114 is not clearly illustrated in
Fig. 6, the navigation system 114 is mainly arranged by a vehicle speed sensor, a
gyroscope, a GPS receiver, a map data input unit, and a navigation control unit. The
vehicle speed sensor corresponds to a sensor for sensing a speed of a vehicle. The
gyroscope detects an azimuth angle change amount of the vehicle based upon an angular
velocity of rotation motion applied to the vehicle. The GPS receiver receives electromagnetic
waves via an antenna, which are transmitted from GPS-purpose satellites, and then,
detects positioning information such as a position, azimuth (traveling direction)
, and the like of the vehicle. The map data input unit corresponds to such an apparatus
which enters data as to map information (will be referred to as "map data" hereinafter)
into the navigation system 114. This map data has been stored in a recording medium
which is generally known as a CD-ROM and a DVD. The navigation control unit calculates
a present position of the vehicle based upon either positioning information acquired
from the GPS receiver or both a travel distance of the vehicle in response to a vehicle
speed and an azimuth change amount of the vehicle. Both the present position calculated
by the navigation control unit and map data corresponding to this present position
are outputted as navigation information from the navigation system 114 to the microcomputer
111.
[0065] Fig. 7 is a flow chart for describing a sequence of an information display process
according to the third embodiment. A routine indicated in this flow chart is called
every time a preselected time interval has passed, and then, the called routine is
executed by the microcomputer 111. In a step 11, both a distance data and an image
data (for example, reference image data) are read. In the third embodiment in which
three primary color images are outputted from each of the main camera 102 and the
sub-camera 103, three pieces of image data (will be referred to as "primary color
image data" hereinafter) corresponding to each of the primary color images are read
respectively.
[0066] In a step 12, three-dimensional objects are recognized which are located in front
of the own vehicle. When the three-dimensional objects are recognized, first of all,
noise contained in the distance data is removed by a group filtering process. In other
words, parallaxes "Ni" which maybe considered as low reliability are removed. A parallax
"Ni" which is caused by mismatching effects due to adverse influences such as noise
is largely different from a value of a peripheral parallax "Ni", and owns such a characteristic
that an area of a group having a value equivalent to this parallax "Ni" becomes relatively
small. As a consequence, as to parallaxes "Ni" which are calculated as to the respective
pixel blocks, change amounts with respect to parallaxes "Ni" in pixel blocks which
are located adjacent to each other along upper/lower directions, and right/left directions,
which are present within a predetermined threshold value, are grouped. Then, dimension
of areas of groups are detected, and such a group having a larger area than a predetermined
dimension (for example, 2 pixel blocks) is judged as an effective group. On the other
hand, parallaxes "Ni" belonging to such a group having an area smaller than, or equal
to the predetermined dimension is removed from the distance data, since it is so judged
that reliability of the calculated parallaxes "Ni" is low.
[0067] Next, based upon both the parallax "Ni" extracted by the group filtering process
and the coordinate position on the image plane, which corresponds to this extracted
parallax "Ni", a position on a real space is calculated by employing the coordinate
transforming formula which is well known in this field. Then, since the calculated
position on the real space is compared with the position of the road plane, such a
parallax "Ni" located above the road plane is extracted. In other words, a parallax
"Ni" equivalent to a three-dimensional object (will be referred to as "three-dimensional
object parallax" hereinafter) is extracted. A position on the road surface may be
specified by calculating a road model which defines a road shape. The road model is
expressed by linear equations both in the horizontal direction and the vertical direction
in the coordinate system of the real space, and is calculated by setting a parameter
of this linear equation to such a value which is made coincident with the actual road
shape. The recognizing unit 112 refers to the image data based upon such an acquired
knowledge that a white lane line drawn on a road surface owns a high luminance value
as compared with that of the road surface. Positions of right-sided white lane line
and left-sided white lane line may be specified by evaluating a luminance change along
a width direction of the road based upon this image data. In the case that a position
of a white lane line is specified, changes in luminance values may be evaluated as
to each of the three primary color image data. Alternatively, for instance, a change
in luminance values as to specific primary color image data such as only a red image,
or only both a red image and a blue image may be evaluated. Then, a position of a
white lane line on the real space is detected by employing distance data based upon
the position of this white lane line on the image plane. The road model is calculated
so that the white lane lines on the road are subdivided into a plurality of sections
along the distance direction, the right-sided white lane line and the left-sided white
lane line in each of the sub-divided sections are approximated by three-dimensional
straight lines, and then, these three-dimensional straight lines are coupled to each
other in a folded line shape.
[0068] Next, the distance data is segmented in a lattice shape, and a histogram related
to three-dimensional object parallaxes "Ni" belonging to each of these sections is
formed every section of this lattice shape. This histogram represents a distribution
of frequencies of the three-dimensional parallaxes "Ni" contained per unit section.
In this histogram, a frequency of a parallax "Ni" indicative of a certain three-dimensional
object becomes high. As a result, in the formed histogram, since such a three-dimensional
object parallax "Ni" whose frequency becomes larger than, or equal to a judgment value
is detected, this detected three-dimensional object parallel "Ni" is detected as a
candidate of such a three-dimensional object which is located in front of the own
vehicle. In this case, a distance defined up to the candidate of the three-dimensional
object is also calculated. Next, in the adjoining sections, candidates of three-dimensional
objects, the calculated distances of which are in proximity to each other, are grouped,
and then, each of these groups is recognized as a three-dimensional object. As to
the recognized three-dimensional object, positions of right/left edge portions, a
central position, a distance, and the like are defined as parameters in correspondence
therewith. It should be noted that the concrete processing sequence in the group filter
and the concrete processing sequence of the three-dimensional object recognition are
disclosed in the above-mentioned
Japanese Laid-open patent Application No. Hei-10-285582, which may be taken into account, if necessary.
[0069] In a step 13, the control unit 113 judges as to whether or not the present traveling
condition corresponds to such a condition that color information of the three-dimensional
objects is suitably produced. As will be explained later, the color information of
the three-dimensional objects is produced based upon luminance values of the respective
primary color image data. It should be understood that color information which has
been produced by employing primary color image data as a base under the normal traveling
condition can represent an actual color of a three-dimensional object in high precision.
However, in a case that the own vehicle is traveled through a tunnel, color information
of a three-dimensional object which is produced based upon an image base is different
from actual color information of this three-dimensional object, because illumination
and illuminance within the tunnel are lowered. As a consequence, in order to avoid
that color information is erroneously produced, a judging process of the step 13 is
provided before a recognizing process of a step 14 is carried out. A judgment as to
whether or not the own vehicle is traveled through the tunnel may be made by checking
that the luminance characteristics of the respective primary color image data which
are outputted in the time sequential manner are shifted to the low luminance region,
and/or checking a turn-ON condition of a headlight. Since such an event that a lamp
of a headlight is brought into malfunction may probably occur, a status of an operation
switch of this headlight may be alternatively detected instead of a turn-ON status
of the headlight.
[0070] In the case that the judgment result of the step 13 becomes "YES", namely, the present
traveling condition corresponds to the suitable traveling condition for producing
the color information, the process is advanced to the step 14. In this step 14, color
information is produced while each of the recognized three-dimensional objects is
employed as a processing subject. In this process for producing the color information,
first of all, a position group (namely, a set of (i, j)) on an image plane which is
defined in correspondence with the three-dimensional parallax "Ni" corresponding to
a group which is recognized as a three-dimensional object within a two-dimensional
plane (ij plane) defined by distance data. Next, in each of the primary color image
data, a luminance value of this defined position group is detected. In this embodiment
with employment of three sets of the above-explained primary color image data, a luminance
value (will be referred to as "R luminance value" hereinafter) of a position group
in a red image is detected; a luminance value (will be referred to as "G luminance
value" hereinafter) of a position group in a green image is detected; and a luminance
value (will be referred to as "B luminance value" hereinafter) of a position group
in a blue image is detected. Then, in order to specify a featured color of this three-dimensional
object, either a most frequent luminance value or an averaged luminance value of the
position group is recognized as the color information of this three-dimensional object
based upon the luminance value (correctly speaking, set of luminance value corresponding
to position group) detected in each of the primary color image data. Accordingly,
in this embodiment, the color information of the three-dimensional object becomes
a set of the three color components made of the R luminance value, the G luminance
value, and the B luminance value. For instance, in the case that a body color of a
preceding-traveled vehicle is white, or a wear color of a pedestrian is white, color
information of this preceding-traveled vehicle, or the pedestrian may be produced
as R luminance value = "255"; G luminance value = "255"; and B luminance value = "255."
[0071] On the other hand, in the case that the judgment result of this step 13 becomes "NO",
namely, the present traveling condition corresponds to such an improper traveling
condition for producing the color information, the process is advanced to a step 15.
In this case, color information of three-dimensional objects is specified based upon
the color information of the three-dimensional objects which have been produced under
the proper traveling condition, namely, the color information which has been produced
in the preceding time (step 15) . First, the control unit 113 judges as to whether
or not such three-dimensional objects which are presently recognized have been recognized
in a cycle executed in the previous time. Concretely speaking, a three-dimensional
object is sequentially selected from the three-dimensional objects which are presently
recognized, and then, the selected three-dimensional object is positionally compared
with the three-dimensional object which has been recognized before a predetermined
time. Normally speaking, even when a traveling condition is time-sequentially changed,
there is a small possibility that a move amount along a vehicle width direction and
a move amount along a vehicle height direction as to the same three-dimensional object
are largely changed. As a consequence, since such a judging operation is carried out
as to whether or not a move amount of the three-dimensional object along the vehicle
width direction (furthermore, move amount thereof to vehicle height direction) is
smaller than, or equal to a predetermined judgment value, it can be judged as to whether
or not the presently recognized three-dimensional object corresponds to such a three-dimensional
object which has been recognized within the cycle executed in the previous time (namely,
judgment as to identity of three-dimensional objects recognized in different times).
[0072] In this judging operation, as to no three-dimensional object identical to the three-dimensional
object recognized before the predetermined time, namely, such a three-dimensional
object which is newly recognized in this cycle, color information thereof is specified
as "not recognizable." On the other hand, as to such a three-dimensional object which
has been continuously recognized from the previous cycle, the color information which
has already been produced is specified as color information thereof. In this case,
as to such a three-dimensional object whose color information has been produced under
the proper traveling condition, since the color information has already been produced
in the process of the step 14, this produced color information is specified as the
color information of this three-dimensional object. On the other hand, as to another
three-dimensional object which has been recognized while this three-dimensional object
is being traveled in a tunnel, since color information has not been produced in the
previous cycle, this color information continuously remains under status of "not recognizable."
[0073] In a step 16, a display process is carried out based upon both the navigation information
and the recognition result obtained by the recognizing unit 112. Concretely speaking,
the control unit 113 controls the display device 115 so as to realize display modes
described in the below-mentioned items (1) and (2):
- (1) Both a symbol indicative of a three-dimensional object and a navigation information
are displayed in a superimposing mode.
In a three-dimensional object recognizing operation using a distance data, a position
indicative of the three-dimensional object is represented by a coordinate system (in
this embodiment, three-dimensional coordinate system) in which the position of the
own vehicle is set to a position of an origin thereof. Under such a circumstance,
while the present position of the own vehicle acquired from the navigation system
114 is employed as a reference position, the control unit 113 superimposes a symbol
indicative of the three-dimensional object on map data after this symbol has been
set in correspondence with a position of a target in the real space based upon the
position of the recognized target. In this case, while the control unit 113 refers
to a road model, the control unit 113 defines a road position on the road data in
correspondence with the positions of the three-dimensional objects by setting the
road model, so that the symbols can be displayed on more correct positions.
- (2) Symbols are displayed in predetermined display colors.
[0074] Symbols displayed on map data in the superimpose manner are represented by display
colors corresponding to color information which has been produced/outputted as to
targets thereof. In other words, a symbol representative of a three-dimensional object,
to which red color information (for example, R luminance value : "255", G luminance
value : "0", and B luminance value : "0") is represented by the same display color
as this outputted red color information. Also, another symbol indicative of a three-dimensional
object ("not recognizable") whose color information has not yet been produced/specified
is displayed by employing a preset display color. This display color is preferably
selected to be such a color which is different from the color information recognizable
in the traffic environment, for example, a purple color may be employed.
[0075] Fig. 8 is an explanatory diagram for showing a display condition of the display device
115. Fig. 9 is a schematic diagram for showing an actual traveling condition, in which
three-dimensional objects located in front of the own vehicle and colors (for example,
body colors etc.) of these three-dimensional objects are indicated. In Fig. 8, in
such a case that three automobiles are recognized, and only one two-wheeled vehicle
is recognized (see Fig. 9), map data is displayed by employing a so-called "driver'
s eye" manner, and symbols indicative of the respective three-dimensional objects
are displayed in such a case that these symbols are superimposed on this map data.
In Fig. 8, as one example, while designs which simulate the three-dimensional objects
are employed, the symbols indicative of these three-dimensional objects are represented
by display colors corresponding to the color information of the recognized three-dimensional
objects.
[0076] Also, the control unit 113 may alternatively control the display device 115 so that
as represented in this drawing, the dimensions of the symbols to be shown are relatively
different from each other in response to the dimensions of the recognized three-dimensional
objects other than the above-explained conditions (1) and (2). Further, the control
unit 113 may control the display device 115 in order that the symbols are represented
by the perspective feelings. In this alternative case, the further a three-dimensional
object is located far from the own vehicle, the smaller a display size of a symbol
thereof is decreased in response to a distance from the recognized three-dimensional
object to the own vehicle. Also, in such a case that a symbol which is displayed at
a positionally far position is overlapped with another symbol which is displayed at
a position closer than the above-described far position with respect to the own vehicle,
the control unit 113 may alternatively control the display device 115 so that the
former symbol is displayed on the side of the upper plane, as compared with the latter
symbol. As a consequence, since the far-located symbol is covered to be masked by
the near-located symbol, the visual recognizable characteristic of the symbols may
be improved, and furthermore, the positional front/rear relationship between these
symbols may be represented.
[0077] As previously explained, in accordance with this embodiment, a target (in this embodiment,
three-dimensional object) which is located in front of the own vehicle is recognized
based upon a color image and further, color information of this three-dimensional
object is produced and then is outputted. Then, a symbol indicative of this recognized
target and navigation information are displayed in the superimposing mode. In this
case, the display device 115 is controlled so that the symbol to be displayed becomes
such a display color corresponding to the color information outputted as to the target.
As a result, the traveling condition which is actually recognized by the car driver
may correspond to the symbols displayed on the display device 115 in the coloration,
so that the colorative incongruity feelings occurred between the recognized traveling
condition and the displayed symbols can be reduced. Also, since the display corresponds
to the coloration of the actual traveling environment, the visual recognizable characteristic
by the user (typically, car driver) can be improved. As a result, since the user convenient
characteristic can be improved by the functions which are not realized in the prior
art, the product attractive force can be improved in view of the user friendly aspect.
[0078] It should also be understood that when the symbols corresponding to all of the recognized
three-dimensional objects are displayed, there is such a merit that the traveling
conditions are displayed in detail. However, the amount of information displayed on
the screen is increased. In other words, such an information as a preceding-traveled
vehicle which is located far from the own vehicle is also displayed which has no direct
relationship with the driving operation. In view of such an idea for eliminating unnecessary
information, a plurality of three-dimensional objects which are located close to the
own vehicle may be alternatively selected, and then, only symbols corresponding to
these selected three-dimensional objects may be alternatively displayed.
[0079] Also, the third embodiment is not limited only such a symbol display operation that
a symbol is displayed by employing a display color which is completely made coincident
with a color component (namely, R luminance value, G luminance value, and B luminance
value) of produced color information. In other words, this display color may be properly
adjusted within a range which may expect that there is no visual difference among
the users. Furthermore, the present invention may be applied not only to the display
manner such as the driver's eye display manner, but also a bird's eye view display
manner (for example, bird view) and a plan view display manner.
[0080] Also, since the stereoscopic camera is constituted by one pair of the main and sub-cameras
which output the color images, the dual function can be realized, namely, the function
as the camera which outputs the color image and the function as the sensor which outputs
the distance data by the image processing system of the post stage thereof. The present
invention is not limited to this embodiment. Alternatively, in addition to the above-described
function, a similar function to that of the present embodiment may be achieved by
combining a single-eye camera for outputting a color image with a well-known sensor
such as a laser radar and a millimeter wave radar, capable of distance data. Also,
if color information of three-dimensional objects located in front of the own vehicle
is merely recognized and symbols are simply displayed by employing display colors
corresponding to the color information of the recognized three-dimensional objects,
then a sensor for outputting distance data is not always provided. In this alternative
case, since the well-known image processing technique such as an optical flow, or
a method for detecting a color component which is different from a road surface is
employed, a three-dimensional object may be recognized from image data. It should
also be understood that since distance data is employed, positional information of
a three-dimensional object may be recognized in higher precision. As a consequence,
since this positional information is reflected to a display process, a representation
characteristic of an actual traveling condition on a display screen may be improved.
[0081] Also, in such a case that the recognizing unit 112 judges that a warning is required
to a car driver based upon a recognition result of a target, this recognizing unit
112 may alternatively operate the display device 115 and the speaker 116 so that the
recognizing unit 112 may give an attention to the car driver. Alternatively, the recognizing
unit 112 may control the control device 117, if necessary, so as to perform a vehicle
control operation such as a shift down operation and a braking control operation.