Color video system using data compression and decompression

Claims

We claim as our invention:

1. A method of generating a color video display by the compression and decompression of digital data extracted from a color image to be displayed, said method comprising the steps of

dividing said color image to be displayed into a matrix of blocks, each block comprising a matrix of pixels,

storing data identifying a multiplicity m of different colors, said data being stored in a color map memory having a unique address for the data identifying each different color,

selecting different pairs of said m colors for different blocks of the color image to be displayed,

generating a pixel data bit for each pixel in each of said different blocks, the value of each pixel data bit identifying one of the pair of colors selected for the block in which the corresponding pixel is located,

generating different pairs of binary numbers representing the color map memory addresses of said different pairs of said m colors selected for different blocks,

reading out of the color map memory the stored data representing the particular color selected for each pixel, in response to the data bit for that pixel and the corresponding one of said binary numbers representing the address of one of the colors selected for the block containing that pixel,

using the data read out of the color map memory to generate a video display comprised of pixels having the selected colors as identified by the data read out of said color map memory, and

changing the data stored in the color map memory and thereby changing the video display generated by the data read out of the color map memory.

2. The method of claim 1 wherein each block comprises at least a 4.times.4 pixel matrix.

3. The method of claim 1 wherein the value of m is at least 256, and each of said binary numbers is at least 8 bits in length.

4. The method of claim 1 wherein said stored data identifies each of said m preselected colors by at least two binary numbers, one of said numbers identifying the intensity of the color and at least one other number identifying the hue of the color.

5. The method of claim 1 wherein said stored data representing said m colors comprises the data needed to generate a video display of a pixel having any of said m colors.

6. The method of claim 1 wherein said stored data representing said m colors includes data identifying a desired luminance level Y and two desired chrominance levels (R-Y) and (B-Y) for each of said m colors.

7. The method of claim 1 wherein said stored data representing said m colors includes data identifying desired Y, I and Q levels for each of said m colors.

8. The method of claim 1 wherein data identifying the addresses of the color pairs selected for the various blocks, and the data bits for the various pixels in each block, are stored in a block buffer memory from which said data can be read out in a desired sequence to address said color map memory, and

which includes the step of reading said data out of said block buffer memory in the desired order of appearance of said pixels in a video display generated therefrom.

9. The method of claim 8 which includes the step of changing the data stored in said block buffer memory for selected blocks or selected pixels to produce an animated video display.

10. The method of claim 8 wherein the data stored in said block buffer memory comprises the pixel data bits and the color map memory address data for the entire matrix of blocks in at least one frame of the desired video display.

11. The method of claim 8 wherein the pixel data bits and the color map memory address data for each block are stored in a common address location in said block buffer memory, and which includes the steps of

addressing said block buffer memory in the order in which the pixels represented by the data therein are to be generated in the video display,

reading out of each addressed location of the block buffer memory two separate data bytes representing the two selected color map addresses for the corresponding block, and

reading successive pixel data bits from the addressed location of the block buffer memory and transmitting to the color map memory a corresponding one of the two data bytes representing the two selected color map addresses, the value of each pixel data bit determining which of the two data bytes is transmitted to the color map memory.

12. The method of claim 8 wherein the chrominance data read out of said color map memory for each of said m colors is transformed by gain and offset values stored in a color space transformation memory, said gain and offset values being selected according the value of the luminance data read out of the color map memory.

13. The method of claim 1 wherein said stored data representing said m colors includes data identifying the primary color components R, G and B for each said m colors.

14. A method of generating animated color video graphics by the compression and decompression of digital data extracted from the color images to be displayed, said method comprising the steps of

producing multiple color images from a multiplicity m of preselected colors,

dividing each image to be displayed into a matrix of blocks, each block comprising a matrix of pixels,

storing data identifying a multiplicity m of different colors in a color map memory having a unique address for the data identifying each different color, said data indentifying a desired luminance level Y and two desired chrominance levels (R-Y) and (B-Y) for each of said m colors,

selecting different pairs of said m colors for different blocks of the color image to be displayed,

generating a pixel data bit for each pixel in each of said different blocks, the value of each pixel data bit identifying one of the pair of colors selected for the block in which the corresponding pixel is located,

generating different pairs of binary numbers representing the color map memory addresses of said different pairs of said m colors selected for different blocks,

storing the data identifying the addresses of the color pairs selected for the various blocks, and the data bits for the various pixels in each block, in a block buffer memory from which said data can be read out in a desired sequence to address said color map memory,

reading said data out