Color image data compression
AssigneeHewlett-Packard Indigo B.V.
InventorsNoam SHAHAM, Gideon AMIR, Ram DAGAN, Michael MELAMED
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Abstract
Color image data is compressed by determining the number of colors within a cell of an input image, each cell comprising an N×M array of pixels; in response to determining that the number of colors is greater than a first predetermined threshold, compress the cell using lossy compression; and in response to determining that the number of colors is less than the first predetermined threshold, reduce the number of colors.
Claims16
1-20. (canceled)
A method comprising:
- determining, by a processor, the number of colors within a cell of an input image, each cell comprising an N×M array of pixels;
- and
- in response to determining that the number of colors is greater than a first predetermined threshold, compressing, by the processor, the cell using lossy compression;
- in response to determining that the number of colors is less than or equal to the first predetermined threshold, reducing, by the processor, the number of colors by:
- determining whether the number of colors is 2;
- in response to determining that the number of colors is 2, determining the distance between the two colors;
- determining whether the distance between the two colors is less than or equal to a predetermined threshold distance;
- and
- in response to determining that the distance between the two colors is less than or equal to the predetermined threshold distance, averaging the two colors to reduce the number of colors to 1.
An apparatus comprising:
- a processor;
- a memory on which stored machine readable instructions to cause the processor to:
- determine the number of colors within a cell of an input image, each cell comprising an N×M array of pixels;
- in response to a determination that the number of colors is greater than a first predetermined threshold, compress the cell using lossy compression;
- in response to a determination that the number of colors is less than or equal to the first predetermined threshold, reduce the number of colors, wherein to reduce the number of colors, the machine readable instructions are further to cause the processor to:
- determine whether the number of colors is 2;
- in response to a determination that the number of colors is 2, determine the distance between the two colors;
- determine whether the distance between the two colors is less than or equal to a predetermined threshold distance;
- and
- in response to determining that the distance between the two colors is less than or equal to the predetermined threshold distance, average the two colors to reduce the number of colors to 1.
A non-transitory computer-readable medium comprising machine readable instructions that when executed by a processor cause the processor to:
- determine the number of colors within a cell of an input image, each cell comprising an N×M array of pixels;
- and
- compress the cell using lossy compression in response to a determination that the number of colors is greater than a first predetermined threshold;
- and
- reduce the number of colors in response to a determination that the number of colors is less than or equal to the first predetermined threshold, where to reduce the number of colors, the machine readable instructions are further to cause the processor to:
- determine whether the number of colors is 2;
- in response to a determination that the number of colors is 2, determine the distance between the two colors;
- determine whether the distance between the two colors is less than or equal to a predetermined threshold distance;
- and
- in response to determining that the distance between the two colors is less than or equal to the predetermined threshold distance, average the two colors to reduce the number of colors to 1.
Dependencies are inferred from the claim text.