Image data compression and decompression
US6683979B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1999 |
| Grant date | Jan 27, 2004 |
| Priority date | — |
| Expiry date | Dec 10, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/005
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
System, method and apparatus for compressing and decompressing image data. In an embodiment, a color cell is compressed by: defining at least four luminance levels of the color cell; generating a bitmask for the color cell, the bitmask having a plurality of entries each corresponding to a respective one of the pixels, each of the entries for storing data identifying one of the luminance levels associated with a corresponding one of the pixels; calculating a first average color of pixels associated with a first one of the luminance levels; calculating a second average color of pixels associated with a second one of the luminance levels; and storing the bitmask in association with the first average color and the second average color. In a second embodiment of the present invention, a color cell is compressed by: determining a luminance value (Y) for each pixel of the color cell; selecting a maximum luminance value (YMAX) and a minimum luminance value (YMIN) for the color cell; subdividing the interval YMAX to YMIN into at least two approximately equal subintervals; generating at least one bitmask that associates each pixel of the color cell with one subinterval; and determining a rep…
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