Color video system using data compression and decompression

• US 4,580,134 A
• Filed: 11/16/1982
• Issued: 04/01/1986
• Est. Priority Date: 11/16/1982
• Status: Expired due to Fees

• Current Assignee: Real Time Design Incorporated
• Original Assignee: Real Time Design Incorporated
• Inventors: Campbell, Graham M., DeFanti, Thomas A.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/442,024
• Time in Patent Office: 1,232 Days
• Field of Search: 340/701, 340/703, 340/723, 340/724, 340/725, 340/726, 340/727, 340/747, 340/748, 340/750, 340/792, 340/798, 340/799, 358/133, 358/134, 358/135, 358/138
• US Class Current: 345/589
• CPC Class Codes: G06T 9/005 Statistical coding, e.g. Huffman, run length coding
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables

Abstract

A method of generating a color video display comprises the steps of dividing a 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, the data being stored in a color map memory having a unique address for the data identifying each different color; selecting different pairs of the m colors for different blocks of the color image to be displayed; generating a pixel data bit for each pixel in each of the 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 the different pairs of the 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; and 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 the color map memory.

Claims

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

3. The method of claim 1 wherein each block comprises at least a 4×

4 pixel matrix.

4. 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.

5. 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.

6. 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.

7. 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.

8. 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.

9. 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.

10. 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.

11. 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.

12. 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.

13. 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.

14. 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.

2. 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.

15. 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 of said block buffer memory in the desired order of appearance of said pixels in a video display to be generated therefrom,

reading out of the color map memory the stored data representing the particular color selected for each pixel, in response to the value of 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,

periodically changing the data stored in said block buffer memory for selected blocks or selected pixels to produce an animated video display, 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.

17. The method of claim 15 wherein each block comprises at least a 4×

4 pixel matrix.

18. The apparatus of claim 15 wherein the value of m is at least 256, and each of said binary numbers is at least 8 bits in length.

19. The apparatus of claim 15 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.

20. The apparatus of claim 15 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.

21. The apparatus of claim 15 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.

22. The apparatus of claim 15 wherein said stored data representing said m colors includes data identifying desired Y, I and Q levels for each of said m colors.

23. The apparatus of claim 15 which includes a block buffer memory for storing data identifying the addresses of the color pairs selected for the various blocks, and the data bits for the various pixels in each block, and

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

24. The apparatus of claim 22 which includes means for changing the data stored in said block buffer memory for selected blocks or selected pixels to produce an animated video display.

25. The apparatus of claim 22 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.

26. The apparatus of claim 22 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

means for 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,

means for 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

means for 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.

27. The apparatus of claim 22 which includes means for transforming the chrominance data read out of said color map memory for each of said m colors 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.

16. Apparatus for generating a color video display by the compression and decompression of digital data extracted from a color image to be displayed, said apparatus comprising the combination of

a color map memory for storing data identifying a multiplicity m of different colors and having a unique address for the data identifying each different color,

means for generating a pixel data bit for each pixel in a color image divided into a matrix of blocks, each block comprising a matrix of pixels, the value of each pixel data bit identifying one of a pair of said m colors selected for the block in which the corresponding pixel is located,

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

means for reading out of said 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,

means for generating a video display comprised of pixels having the selected colors as identifed by the data read out of said color map memory, and

means for 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.

28. A digital color video system as set forth in claim 16 for displaying animated color video graphics, said system including microprocessor means operatively associated with said block buffer memory for changing the data therein for selected blocks or selected pixels to produce an animated video display.

29. 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 identifying 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 of said block buffer memory in the desired order of appearance of said pixels in a video display to be generated therefrom,

reading out of the color map memory the stored data representing the particular color selected for each pixel, in response to the value of 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,

periodically changing the data stored in said block buffer memory for selected blocks or selected pixels to produce an animated video display, 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.

31. A digital color video graphics system as set forth in claim 29 wherein said block buffer memory stores encoded data for the entire matrix of blocks in at least one complete frame of a desired video display.

32. A digital color video system as set forth in claim 29 wherein the data stored in said color map memory comprises the data needed to generate a video display of a pixel having any of said m colors.

33. A digital color video system as set forth in claim 29 wherein the data stored in said color map memory includes data identifying a desired luminance level Y and two desired chrominance levels (R-Y) and (B-Y) for each of said m colors.

34. A digital color video system as set forth in claim 29 wherein the data stored in said color map memory includes data identifying desired Y, I and Q levels for each of said m colors.

35. A digital color video system as set forth in claim 29 wherein the data stored in said block buffer memory comprises the pixel code bits and the color map memory address data for the entire matrix of blocks in at least one frame of the desired video display.

36. A digital color video system as set forth in claim 29 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

means for 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,

means for 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

means for reading successive pixel code 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 code bit determining which of the two data bytes is transmitted to the color map memory.

37. A digital color video system as set forth in claim 29 which includes means for transforming the chrominance data read out of said color map memory for each of said m colors 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,

reading out of said color map memory the color data stored at the addresses represented by said binary numbers transmitted to said color map memory, and

generating a video display comprising pixels having colors determined by the data read out of said color map memory.

39. A method as set forth in claim 37 for displaying animated color video graphics, said method including changing the data in said block buffer memory for selected blocks or selected pixels to produce an animated video display.

40. A method as set forth in claim 37 wherein encoded data for the entire matrix of blocks in at least one complete form of a desired video display is stored in said block buffer memory.

41. A method as set forth in claim 37 wherein the data stored in said color map memory comprises the data needed to generate a video display of a pixel having any of said m colors.

42. A method as set forth in claim 37 wherein the data stored in said color map memory includes data identifying a desired luminance level Y and two desired chrominance levels (R-Y) and (B-Y) for each of said m colors.

43. A method as set forth in claim 37 wherein the data stored in said block buffer memory comprises the pixel code bits and the color map memory address data for the entire matrix of blocks in at least one frame of the desired video display.

44. A method as set forth in claim 37 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 code 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 code bit determining which of the two data bytes is transmitted to the color map memory.

45. A method as set forth in claim 37 which includes the step of transforming the chrominance data read out of said color map memory for each of said m colors by gain and offset values stored in a color space transformation memory, said gain and offset values being selected according to the value of the luminance data read out of the color map memory.

30. A digital color video system for displaying images which have been divided into a matrix of blocks, each block comprising a matrix of pixels, said system using the compression and decompression of digital data extracted from said images and comprising

a color map memory for storing data for generating a video display of pixels having any of a multiplicity m of different preselected colors, the data for each of said m colors having a separate address in said color map memory,

a block buffer memory for receiving and storing encoded data representing different pixel color patterns for different blocks, the encoded data for a given block including

a pair of binary numbers representing addresses for two of said m preselected colors,

a code bit for each pixel in the block, the value of said code bit representing one of the two colors whose addresses are represented by said pair of binary numbers,

means for reading said binary numbers out of said block buffer memory and transmitting to said color map memory one of said binary numbers for each pixel represented by a code bit, said binary numbers being transmitted in the same order in which the corresponding pixels are to be generated in the video display,

means for reading out of said color map memory the color data stored at the addresses represented by said binary numbers transmitted to said color map memory,

means for generating a video display comprising pixels having colors determined by the data read out of said color map memory, and

means for 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.

38. A method of displaying color video images which have been divided into a matrix of blocks, each block comprising a matrix of pisels, said method using the compression and decompression of digital data extracted from said images and comprising the steps of

storing data for generating a video display of pixels having any of a multiplicity m of different preselected colors in a color map memory, the data for each of said m colors having a separate address in said color map memory,

storing encoded data representing different pixel color patterns for different blocks in a block buffer memory, the encoded data for a given block including a pair of binary numbers representing addresses for two of said m preselected colors,

a code bit for each pixel in the block, the value of said code bit representing one of the two colors whose addresses are represented by said pair of binary numbers,

reading said binary numbers out of said block buffer memory and transmitting to said color map memory one of said binary numbers for each pixel represented by a code bit, said binary numbers being transmitted in the same order in which the corresponding pixels are to be generated in the video display,

reading out of said color map memory the color data stored at the addresses represented by said binary numbers transmitted to said color map memory,

generating a video display comprising pixels having colors determined 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.

46. A method of generating a color video display comprising the steps of

dividing a 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 plurality of selectable color map memories each 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 bir 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 binary numbers representing the selectable color map memory and the color map memory addresses of said different pairs of said m colors selected for different blocks,

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

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

47. A method of generating a color video display comprising the steps of

dividing a color imge 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 the pixel,

using the data read out of the color map memory to generate a video display comprised of pixels having the selectec colors ad 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.