[0001] The present invention refers to a ball-trapping device which has associated electronic
means for accurately detecting the position of successive impacts on a target and
for displaying the scores on a screen. Said electronic means can be connected to one
or more remote centres for competing with other users or for participating in shooting
games. The invention also refers to a method used for carrying out such detection.
[0002] The ball-trapping devices, also called ball-catching devices, are well known since
certain time ago and they consist in a casing made of a material having impact strength
and provided with an open front face having means for removably fastening a target
covering such open face. The target is typically a sheet material, such a paperboard
or stiff paper, through which the projectiles can go and on which external face a
motive to be shot is depicted, such as several concentric rings around a central disk.
Thus, the user may shoot the target and the projectiles, generally plastic or lead
balls, are collected within the casing after crossing said sheet material. When the
target is very damaged because of a large number of impacts it is replaced by a new
one.
[0003] The utility model ES-A-1023727 is an example of one of such ball-trapping device
which, in this case is dismountable.
[0004] The holes produced by each successive shot on the target evidence the place of the
impact and the target can be visually checked for assessing the level of aim. However,
for each new shot, it is necessary that the shooter physically goes close to the target
for performing such check and the shooter must remind the positions of all the previous
shots for discriminating the position of the last shot. This is boring and tiresome.
In addition, the holes are not clean but show tears on their edges and often a new
shot very close to another one modifies the hole pierced by such former shot without
producing a new hole. All this makes the reading of successive impacts on the target
difficult.
[0005] It has been tried to provide ball-trapping devices having means for helping to accurately
determine the place of the impacts on the target.
[0006] The utility model ES-A-1001945 discloses a device in which the casing has a central
face with a plurality of openings arranged according to a geometric pattern and a
slot for introducing and withdrawing a sheet constituting a target, on which a series
of numbers, graphics or colours have been printed which coincide with such openings
and which can be seen through them. Such graphic target further comprises a printed-circuit
board connected to an electronic panel which has built-up a high visibility scoreboard
showing the scores. The utility model does not disclose which means are used for converting
the impacts of the projectiles in electronic signals which may be handled by such
printed-circuit board.
[0007] The patent ES-A-8305921 discloses a process and a device for assessing the level
of aim on a target. The apparatus comprises a device to pass different printed target
on a band through the open front face of a casing and two detection systems. One of
those systems is kept in position close to the travel path of a target and it is used
for measuring the distance from an entrance hole at the centre of the target in the
direction in which the target is travelling through the apparatus. The other system
is mounted on a cross sliding element and is displaceable in straight angle in the
direction in which the target is travelling and it measures the distance from the
hole to the centre of the target in such cross direction. The two distances are vectorially
added by a computer and the result is multiplied by a calibrating factor. The end
score can be displayed on a screen or printed. Such detection systems comprise orthogonally
arranged photoelectric barriers.
[0008] This system only allows determining the position of a single hole on the target;
therefore, it is required to replace the target after each shot. In addition, to cover
the whole of the target area with said two photoelectric barriers, a great number
of sensors is required which results in the apparatus having a high price. On the
other hand, such great number of sensors generates a relatively high power consumption
which makes unworkable to supply the device with cells or reloadable batteries, preventing
its power autonomy.
[0009] The patent ES-A-2025007 let know a system for obtaining a reading of the game surface
of a real target, although in this case it is an electronic machine for a darts game.
The system includes two imaging digital cameras arranged at 90° from each other and
each encompassing the whole of the front surface of the target where the darts are
stuck. The signals of both cameras are treated in a module of a CPU to provide as
a result a two dimensional image of the target with the darts stuck displayed on a
viewing screen.
[0010] Although this device uses imaging electronic cameras for reading the target, the
result obtained is a two-dimensional image thereof but such image does not offers
the calculated position on coordinates of each successive shot.
[0011] An object of the present invention is to provide a ball-trapping device having an
electronic detection of the impact on a target provided with a digital camera for
taking images of the target back face, from which electronic means are able to implement
a method for detecting the centre of each successive impact.
[0012] Another object of the present invention is to provide a self-powered ball-trapping
device with electronic detection of the impact on a target and which can be connected
to a local or remote receiving and/or retransmitting centre to display the scores
and/or participate in shot games competing with other local or remote players.
[0013] Still another object of the present invention is to provide a detection method to
be used with the above ball-trapping device.
[0014] These objects are achieved, according to the present invention, providing a ball-trapping
device of the kind which comprises a casing, of a material having strength to the
impacts, with a front face having an opening and means for removably fastening a target
covering such opening. This target is typically a sheet of material through which
the projectiles can go and on which external face a motive to be shot is depicted.
The ball-trapping device includes electronic means associated at least partly to said
casing, for detecting the position of at least one impact on said target.
[0015] Such electronic means essentially comprise an electronic camera provided with a corresponding
focusing lens for taking images, an image treating unit, and a centre for data receiving
and/or retransmitting, which can be associated with a viewing screen. Said electronic
camera is arranged within the casing in a protected chamber formed at least partly
by a transparent wall, encompassing in its focal field the back face of the target
for taking images of each of successive shots after it occurs. The material of which
the target is made is sufficiently opaque in order to provide a dark ambience within
the casing in said back face of the target contrasting with an external natural or
artificial illumination, necessary for shooting practice. Thanks to this, any hole
in the target is obtained by the camera as a light spot on a dark background. Thus,
the impact of each successive shot produces a new hole or a modification of a previous
hole which is obtained by the image-taking camera.
[0016] The successive images obtained are handled by said image treating unit to determine
the projectile geometric centre at each successive impact, the scores are displayed
on said viewing screen associated with the mentioned data receiving and/or retransmitting
centre and/or are retransmitted through a telecommunication network to one or more
remote centres to be shown or compared to scores obtained by other remote users with
which it is possible to compete.
[0017] The processing of the images obtained preferably comprises a prior step of calibrating
the position of the image depending on a parameter such as a printed mark on the back
face of the target or control holes and the processing is performed by means of image
processing algorithms and artificial intelligence operations, and by means of comparing
the images obtained with images stored in a memory associated with said image treating
unit. Said algorithm comprises first storing in a memory the image obtained after
a first shot; then passing the successive images obtained to a treating unit wherein
a grey scale intensity comparison between each new in-coming image and the last memory-stored
image is performed; and last, storing each new image resulting from comparison by
rejecting or replacing the image of the former shot. From both horizontal and vertical
projection of the image resulting from comparison, two vectors X and Y are obtained
which are filtered with a filtering gauge depending on the kind of ammunition and
shot to be detected, said filtering gauge being retrieved from an empiric database
of filtering patterns. After filtering, the impact central point is determined from
thresholds in the grey scale. Also, a second database is used to counterbalance the
central point determined with techniques of artificial intelligence based on back-propagation
neuronal networks. Such central point is obtained with reference to a corner of the
image.
[0018] As the target is being used, holes and modifications (widening) of old holes are
being accumulated, therefore at a given moment the target is so damaged that is hard
or impossible to assess the effects of new impacts and it is necessary to replace
it. For this, the method of the present invention includes a function which comprises
to pick-up by means of a microphone a noise produced by each successive impact within
the casing, which is an indicative that the shot did occur and that a new image of
the target back face has to be obtained. The image obtained corresponding to the same
shot which produced the last noise is compared as explained above with the stored
image corresponding to the former shot. In the case of no difference can be seen between
such two consecutive images, the system issues a warning about the convenience of
replacing the target.
[0019] Preferably, the image treating unit is built-in within the casing and comprise a
digital signal processor DSP having associated memories for storing images and processing
them on the base of neuronal networks while said data receiving and/or retransmitting
centre is a local computing centre associated with a viewing screen located close
to the place from which the user is shooting. The result from the impact detection
is transmitted through suitable transmitting means from the image-treating unit, within
the casing, to said local computing centre. Said transmitting means can use different
means such as a connecting cable, infrared rays or radio-frequency waves. The local
computing centre can be any digital computer device of those generally available in
the market, such as personal digital assistant PDA or a personal computer PC, which
is provided, according to the cases, with a cable connecting port, an infrared receiver
or a radio-frequency wave receiver.
[0020] Alternatively it is also possible that the image-treating unit is located at a place
external from the casing. In this case, the treating unit preferably comprises a digital
signal processor DSP having associated memories for storing images and processing
them on the basis of neuronal networks, a cable connection being provided between
the electronic camera and the image-treating unit. Advantageously, such external image-treating
unit is integrated in a personal digital assistant PDA or personal computer PC which
also carries out the functions of the data receiving and/or retransmitting centre.
[0021] The electronic camera is constituted by a CCD device having MOS technology and the
power consumption of the camera and image data treating unit, when included in the
casing, is relatively low. This allows to supply electric power to such systems by
means of one or more batteries or cells associated with said casing, therefore the
ball-trapping device is self-powered. However, when said cable connection to the local
computing unit is used, it is also possible to supply such systems through an electric
line included in such cable and from the power supply of the computing unit itself.
Another variation includes an input in said casing for connection to an external power
supply to power supply those systems that would require it.
[0022] The invention will be more apparent from following detailed description of an exemplary
embodiment with reference to the accompanying drawings, in which:
Fig. 1 is a perspective view of part of the ball-trapping device of the present invention;
Fig. 2 is a diagrammatic scheme showing the parts and connections of the ball-trapping
device of the present invention;
Fig. 3 is a flow chart illustrating the method of electronic detection used with the
ball-trapping device of Fig. 2.
[0023] Referring first to Fig. 1, the ball-trapping device according to the present invention
has a part designed to support and show the target, which is similar to that of the
conventional ball-trapping devices. This part comprises a casing 1, of a material
having impact strength, with a front face provided with an opening and means for removably
fastening a target 2 covering such opening. Said fastening means are, in the illustrated
example, small wings 15 arranged on three edges of said opening so that they form
slots in which the target 2 can slide. The target 2 is in the form of a sheet of a
material through which the projectiles can go and on which external face a motive
to be shot, such as several concentric rings around a central disk, is depicted.
[0024] According to Fig. 2, the ball-trapping device of the present invention further comprises
electronic means for detecting the position of each successive impact on the target
2 and show the scores. A part of such electronic means can be placed in a chamber
within or associated with said casing 1 and the other part is placed outside the casing
1, at a local or remote place. Preferably, the components associated with the casing
1 essentially comprise an electronic camera 3 with a focusing lens 16 for picking-up
the images and an image-treating unit 4 connected to the camera 3 for electronically
processing the images obtained. According to a preferred exemplary embodiment, the
electronic camera 3 is arranged in a protected chamber 8 formed at least partly by
a transparent wall 9, of a material such as reinforced glass, so that the camera 1
encompasses in its focal field the back face of the target 2 to pick-up after each
shot successive images of said back face where new holes or modifications of previous
holes are successively appearing produced by the successive impacts. However, the
electronic camera could be arranged within a protected housing, linked to the casing
1 through an arm or the like, stiff enough to provide stability to the image, for
encompassing in its focal field the front external face of the target and taking images
of them. The image treating unit 4 comprises a digital signal processor DSP having
associated memories for storing images and processing them on the basis of neuronal
networks, and although it is not essential, it is advantageously located within said
protected chamber 8, a compact ball-trapping device with a set of casing 1 including
the electronic image pick-up and treating means 3, 4 being formed. The image-treating
unit 4 is adapted to determine the geometric centre of the projectile at each successive
impact from a processing of the images obtained by the camera 3 applying the method
of the present invention, which will be described below with reference to Fig. 3.
The electronic camera is preferably constituted by a CCD device with MOS technology.
[0025] In the illustrated example, the image treating unit 4 is connected by suitable transmitting
means, such as a connecting cable 5, to a data receiving and/or retransmitting centre
6 connected to a viewing screen 13, where are displayed the results of the impact
detection corresponding to each successive shot. Such data receiving and/or retransmitting
centre is a local computing centre 6, such as a personal digital assistant PDA or
a personal computer PC, provided with an input port for cable connection and a connection
to a telecommunication network 11, such as Internet, for retransmitting said results
to a remote computing centre 7 associated with a viewing screen 14, which can be,
for example, another personal digital assistant PDA or a personal computer PC to which
is connected another ball-trapping device with target impact electronic detection
used by another remote user.
[0026] It is convenient that the local computing centre 6 is located close to the user who
is shooting and for this the connecting cable 5 constitutes a cheap and reliable signal
transmitting means. However, other more sophisticated wireless transmitting means
can be used such as an infrared ray or a radio-frequency wave emitter associated with
the casing 1, for which the personal digital assistant PDA or the personal computer
PC must be provided with an infrared ray or radio-frequency wave receiving port.
[0027] According to another exemplary embodiment not shown, such image treating unit 4 is
located in a place external from the box 1, for example, close to the user who is
hooting, and comprises a digital signal processor DSP having associated memories for
storing the images and processing the same on the basis of neuronal networks preferably
integrated in a personal digital assistant PDA or a personal computer PC which also
has the function of the data receiving and/or retransmitting centre 6 and/or 7 of
Fig. 2. In this case, there would exist an external cable or otherwise connection
between the electronic camera 3 and the image-treating unit 4.
[0028] Additionally, the ball-trapping device includes a microphone 10 within the casing
1 to pick-up a noise produced by each successive impact. Such noise confirms the occurrence
of each shot on the target and, in addition, in combination with the image corresponding
to same shot it serves for determining when the target 2 is so damaged that it is
necessary to be replaced, as described below in relation with the method of the invention.
[0029] It is desirable that the ball-trapping device, at least the set of the casing 1 and
associated electronic image pick-up and treating means 3,4 is energetically autonomous
as possible. For this it includes one or more batteries or cells 12 associated with
said casing 1 for providing power supply to the systems requiring it. Alternatively,
when the electronic image pick-up and treating means 3, 4 associated with the casing
1 are connected via cable 5 to a local computing centre 6, said connecting cable 5
can include an electric line for supplying the electronic means 3, 4 associated with
the box 1 with electric power coming from the power supply of the local computing
unit 6 itself. When the local computing unit 6 is a personal digital assistant PDA
or portable personal computer PC supplied by cells or batteries, the complete system
is self-powered. However, the casing 1 can include an input for a connection to an
external power supply.
[0030] When, as in the example of Fig. 2, the electronic camera 3 picks-up images from the
internal back face, of the target 2, said sheet material of which the target 2 is
made is sufficiently opaque in order to the electronic camera 3 can differentiate
said holes or modifications thereof from the light which, coming from outside, enters
through them, in contrast with the rest of the sheet which remains dark. It is important
to "read" the outlines of the holes, which generally have tears, folds, etc which
are important to determine the shooting centre. Such reading of the outline is achieved
by grey scale comparing with pre-recorded standards. To allow shooting practice with
scarce light, the ball-trapping device includes an external auxiliary source of illumination
(not shown) which is applied on the external face of the target. This helps as well
the user's vision as the pick-up of images by the camera 3.
[0031] Thereafter, with reference to the flow diagram of Fig. 3, the detection method used
according to the present invention is described in the ball-trapping devices with
the electronic detection of the impact on the target above disclosed with relation
to Fig. 1 and 2.
[0032] The method comprises following steps:
First, obtaining (box 30) by means of said electronic camera 3 after each shot at
least one image, represented by box 31, of a face of the target 2 in which appear
successive new holes or modifications of previous holes produced by successive impacts;
then, treating (box 32) by means of such image treating unit 4, the image obtained
(box 31) for improving its definition and process (boxes 33-37) the treated image
for determining the geometric centre of the projectile at each successive impact from
obtained, treated and processed images; and
last, showing (box 38) the scores in one of such viewing screens 13, 14.
[0033] When said image-treating unit 4 is located within the casing 1, the method comprises
transferring with such communication means 5 the result of treatment with such image-treating
unit 4 to a data receiving and/or retransmitting unit, which is a local 6 or remote
7 computing centre.
[0034] The method comprises a step of calibrating the position of the image as a function
of a parameter such as a printed mark or control holes on the target face picked-up
by the camera.
[0035] When the electronic camera 3 encompasses the internal back face of the target 1,
such as in Fig. 2, said algorithm comprises comparing (box 33) the obtained image
(box 31), once treated, with the former image (box 41) that is to say, the last image
stored in memory, according to their grey scale intensities. Each new image resulting
from said comparison is stored replacing the image of the former shot.
[0036] Then, a projection (box 34) of the impact image resulting from previous comparison
on image horizontal and vertical axes is performed, obtaining two vectors X and Y
which are filtered with a filtering pattern depending on the kind of ammunition and
shot to be detected, with the assistance of an empiric database (box 39) for retrieving
such filtering patterns and counterbalancing according to former impacts (box 37).
After such filtering the central point of the impact is detected (box 35) or determined
from grey scale thresholds.
[0037] Last, the method comprises the use of a second database (box 40) to carry out a relocation
of the central point (box 36) determined in the former operation, using techniques
of artificial intelligence (frame 42) based on neuronal networks of back-propagation
type, said point being obtained with reference to a corner of the image.
[0038] It must be pointed out that, although steps of boxes 34-37 are shown in Fig. 3 in
a sequential manner, the operations are carried out simultaneously and interlinked.
[0039] The method of the present invention includes a function for determining when the
target 2 is so damaged that it is necessary to replace it. This function comprises
the steps of: picking-up by means of a microphone 10 a noise produced by each successive
impact within the casing 1; comparing (box 33 in Fig. 3) the image obtained (box 31)
corresponding to same shot that produced last noise with the image stored corresponding
to the former shot (box 40); and in case that a given level of difference is not assessed
between such two consecutive images, 3 issue a warning about the convenience to replace
the target 2.
[0040] One skilled in the art could easily devise several variations and/or modifications
without being out of the scope of the invention as it is defined in the claims appended.
1. Ball-trapping device with electronic detection of the impact on the target of the
kind comprising a casing (1) made of a material having impact strength and with a
front face having an opening and means for removably fastening a target (2) covering
such opening, the target (2) being in the form of a sheet material through which the
projectiles can go, on which external face a motive to be shot is depicted, electronic
means being provided for detecting the position of at least one impact on said target
(2), characterized in that said electronic means comprise an electronic camera (3) having a focusing lens for
picking-up images, an image treating unit (4), and a data receiving and/or retransmitting
centre (6,7) susceptible to be associated with a viewing screen (13, 14), said electronic
camera (3) being arranged to encompass in its focal field a face of the target (2)
and to obtain after each shot successive images of said face on which new holes or
modifications of previous holes produced by successive impacts appear, said image
treating unit (4) being adapted for determining the geometric centre of the projectile
at each successive impact from a treatment of the obtained images, and said data receiving
and/or retransmitting centre (6,7) being adapted for displaying the results on said
viewing screen (13, 14) and/or retransmit them through a telecommunication network.
2. Ball-trapping device according to claim 1, characterized in that said electronic camera (3) is housed in a protected chamber (8) associated with the
casing (1) and encompasses in its focal field the internal back face of the target
(2) through a transparent wall (9).
3. Ball-trapping device according to claim 1, characterized in that said electronic camera is housed in a protected chamber associated with the casing
(1) and encompasses in its focal field the external front face of the target (2) a
support of said chamber being stiff enough to provide stability to the image.
4. Ball-trapping device according to claim 1, characterized in that it includes a microphone (10) within the casing (1) to pick-up a noise produced by
each successive impact, said noise in combination with the image corresponding to
same shot serving to determine when the target (2) is so damaged that it is necessary
to replace it.
5. Ball-trapping device according to claim 1, characterized in that such image treating unit (4) is integrated in a protected chamber (8) associated
with the casing (1) and comprises a digital signal processor DSP with associated memories
for storing images and processing them based on neuronal networks.
6. Ball-trapping device according to claim 5, characterized in that such data receiving and/or retransmitting centre (6, 7) is a local computing centre
(6) having an associated viewing screen (13) located close to a user who is shooting,
means being provided for transmitting the results of said image treatment from the
image treating unit (4) in the box (1) to said local computing centre (6).
7. Ball-trapping device according to claim 6, characterized in that said transmitting means comprise a connection cable (5) for connecting to said local
computing centre (6), the local computing centre (6) being selected from a group including
a Personal digital assistant PDA and a personal computer PC, in each case provided
with an input port for connecting the cable.
8. Ball-trapping device according to claim 6, characterized in that said transmitting means comprise an infrared ray emitter to said local computing
centre (6), the local computing centre (6) being selected from a group including a
Personal digital assistant PDA and a personal computer PC, in each case provided with
an infrared ray receiving port.
9. Ball-trapping device according to claim 6, characterized in that said transmitting means comprise a radio-frequency waves emitter to said local computing
centre (6), the local computing centre (6) being selected from a group including a
Personal digital assistant PDA and a personal computer PC, in each case provided with
a radio-frequency waves receiver
10. Ball-trapping device according to claim 1, characterized in that said image treating unit (4) is located at a place outside the casing (1) and comprises
a digital signal processor DSP with associated memories for storing image and treating
them based on neuronal networks, memories an external connection, such as via cable,
between the electronic camera (3) and the image treating unit (4) being provided.
11. Ball-trapping device according to claim 10, characterized in that the image treating unit (4) is integrated in a personal digital assistant PDA or
personal computer PC which also acts as a data receiving and/or retransmitting centre
(6, 7).
12. Ball-trapping device according to any one of preceding claims, characterized in that it includes one or more batteries or cells (12) associated with said casing (1) for
providing power supply to the systems requiring it, thereby the ball-trapping device
is energetically autonomous.
13. Ball-trapping device according to claim 7, characterized in that said connection cable (5) includes an electric line, those systems in the ball-trapping
device requiring it being supplied with power from the power supply of said local
computing centre (6) itself.
14. Ball-trapping device according to any of claims 1 to 11, characterized in that said casing (1) includes an input for connection to an external power supply to supply
with power the systems of the ball-trapping device requiring it.
15. Ball-trapping device according to any of claims 6 to 11, characterized in that said local computing centre (6) is connected to a remote computing centre (7) through
a telecommunication network.
16. Ball-trapping device according to any one of the preceding claims, characterized in that said electronic camera is constituted by a CCD device having MOS technology.
17. Ball-trapping device according to claim 2, characterized in that said sheet material of which the target (2) is made is sufficiently opaque in order
that the electronic camera (3) can differentiate said holes or modifications thereof
by the light coming from outside, which enters through them, in contrast with the
rest of the dark sheet.
18. Ball-trapping device according to any one of the preceding claims, characterized in that it includes an external auxiliary illumination source which is applied on the external
front face of the target (2).
19. Method of detection applicable to a ball-trapping device having electronic detection
of the impact on a target, the ball-trapping device being of the type comprising a
casing (1) of a material with strength to the impacts, having a front face provided
with an opening and means for removably fastening a target (2) covering said opening,
the target (2) being in the form of a sheet material through which the projectiles
can go, on which external face a motive to be shot is depicted, electronic means being
provided for detecting the position of at least an impact on said target (2),
characterized in that it comprises following steps:
a) obtaining, by means of an electronic camera (3) provided with a system of focusing
lens arranged within the casing (1), at least one image of one face of the target
(2) after each shot, on which face successive new holes or modifications of previous
holes produced by successive impacts appear;
b) treating, by means of an image treating unit (4), the images obtained for improving
its definition and processing the treated images for determining the geometric centre
of the projectile at each successive impact from the obtained, handled and processed
images; and
c) displaying the results in a viewing screen (13, 14).
20. Method, according to claim 19, characterized in that it comprises transferring, using communication means (5), the result of said treatment
carried out by said image treating unit (4), which is located within the casing (1),
to a data receiving and/or retransmitting centre, which is a local (6) or remote (7)
computing centre.
21. Method, according to claim 19, characterized in that said processing of the treated images is carried out through image treatment algorithms
and artificial intelligence operations, and by comparing the obtained images with
images stored in a memory associated with said image treating unit (4).
22. Method, according to claim 21, characterized in that it comprises a prior step of calibrating the position of the image as a function
of a parameter such as a printed mark on the target face picked-up by the camera (3)
or target control holes.
23. Method, according to claim 19, characterized in that the electronic camera (3) encompasses the internal back face of the target (1) and
said algorithm comprises first storing in a memory the image obtained after a first
shot; then passing the successive obtained images to a treating unit in which comparing
their intensity in grey scale between each new in-coming image and the last image
stored in the memory; and last, storing each new image resulting from comparison rejecting
the image of the former shot.
24. Method, according to claim 23, characterized in that it comprises making a projection on horizontal and vertical axes of the image of
the impact resulting from said comparison, thereby obtaining two vectors X and Y which
are filtered with a filtering pattern depending on the kind of ammunition and shot
to be detected, with the assistance of an empiric database for retrieving said filtering
patterns and counterbalancing according to former impacts, and in that after said filtering the central point of the impact is determined from thresholds
in the grey scale.
25. Method, according to claim 24, characterized in that it comprises the use of a second database to carry out a relocation of the central
point determined with techniques of artificial intelligence based on neuronal networks
of the back-propagation kind, said point being obtained with reference to a corner
of the image.
26. Method, according to claim 19, characterized in that the electronic camera (3) encompasses the external front face of the target (1) and
said algorithm comprises first storing in a memory the image obtained after a first
shot; then passing the successive obtained images to a treating unit in which black
points are compared between each in-coming image and the last image stored in the
memory; and storing each new image resulting from comparison rejecting the image of
the former shot.
27. Method, according to claim 26, characterized in that it comprises to make a projection on horizontal and vertical axes of the image of
the impact resulting from said comparison, thereby obtaining two vectors X and Y which
are filtered with a filtering pattern depending on the kind of ammunition and shot
to be detected, with the assistance of an empiric database for retrieving said filtering
patterns and counterbalancing according to former impacts, and in that after said filtering the central point of the impact is determined from thresholds
in the grey scale.
28. Method, according to claim 27, characterized in that it comprises the use of a second database to carry out a relocation of the central
point determined by techniques of artificial intelligence based on neuronal networks
of the back-propagation kind, said point being obtained with reference to a corner
of the image.
29. Method, according to claim 19,
characterized in that it includes a function for determining when the target (2) is so damaged that it
is necessary to replace it, comprising following steps:
1) picking-up by means of a microphone (10) a noise produced by each successive impact
within the casing (1);
2) comparing the image obtained corresponding to same shot that produced last noise
with the image stored corresponding to the former shot; and in case that a given level
of difference is not assessed between said two consecutive images,
3) issue a warning about the convenience to replace the target (2).