| (19) |
 |
|
(11) |
EP 0 319 684 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
06.02.1991 Bulletin 1991/06 |
| (43) |
Date of publication A2: |
|
14.06.1989 Bulletin 1989/24 |
| (22) |
Date of filing: 20.10.1988 |
|
|
| (84) |
Designated Contracting States: |
|
DE FR GB |
| (30) |
Priority: |
23.10.1987 US 111887
|
| (71) |
Applicant: HONEYWELL INC. |
|
Minneapolis
Minnesota 55408 (US) |
|
| (72) |
Inventor: |
|
- Thompson, Eldon John
Ruckersville
Virginia 22968 (US)
|
| (74) |
Representative: Rentzsch, Heinz, Dipl.-Ing. et al |
|
Honeywell Holding AG
Patent- und Lizenzabteilung
Postfach 10 08 65
63008 Offenbach
63008 Offenbach (DE) |
|
| |
|
| (54) |
Display system for color image quantization |
(57) An apparatus for displaying video color images and minimizing buffer memory size
quantizes a video image into a reduced number of corresponding color values. A lookup
table (16) for driving a refresh buffer is encoded with a set of neighboring color
values for transforming a three component color video signal to two-component format.
The two-component signals are stored in a frame buffer (20) of reduced capacity sufficient
to store the quantized color image. When addressed by a raster scan (21) the frame
buffer is read out into a second lookup table (22) for converting the quantized image
into a reduced set of color values. Since no intermediate computing or processing
is required, the transformation is accomplished in real time, allowing contemporaneous
color display while reducing buffer memory size demands.