Systems and Methods for Optimizing Pixel Based Raster Trapping
AssigneeKonica Minolta Laboratory U.S.A., Inc.
InventorStuart Guarnieri
Life of this patent
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Abstract
Methods disclosed permit the identification of frame buffer pixels for trapping. In some embodiments, flags associated with pixels in the frame buffer may be used to provide an indication of pixels for trapping. A bit in a flag associated with a pixel may be set when the pixel is painted, if the luminosity value of the pixel does not exceed a luminosity threshold. In some embodiments, the method discloses a process for updating the value of the bit through the rasterization process. The pixel may be identified as a candidate for trapping based on the value of the at least one bit at trapping time.
Claims20
A computer-implemented method for identifying at least one frame buffer pixel associated with at least one display list object as a candidate for trapping, by associating at least one flag with the at least one frame buffer pixel, the method comprising the computer-implemented steps of:
- calculating a value for a first bit in the at least one flag when rendering the at least one frame buffer pixel to a frame buffer by:
- setting the first bit in the at least one flag, if a luminosity value of the at least one frame buffer pixel does not exceed a luminosity threshold and the object is opaque;
- resetting the first bit in the at least one flag, if the luminosity value of the at least one frame buffer pixel exceeds a luminosity threshold and the object is opaque;
- setting the first bit in the at least one flag, if a blended luminosity value of the at least one frame buffer pixel does not exceed a luminosity threshold and the object is non-opaque;
- and,
- resetting the first bit in the at least one flag, if the blended luminosity value of the at least one frame buffer pixel exceeds a luminosity threshold and the object is non-opaque;
- and
- identifying the at least one frame buffer pixel as a candidate for trapping, if the first bit in the flag associated with the at least one frame buffer pixel has been set.
A computer-readable medium that stores instructions, which when executed by a processor perform steps in a method for identifying at least one frame buffer pixel associated with at least one display list object as a candidate for trapping, by associating at least one flag with the at least one frame buffer pixel, the method comprising the computer-implemented steps of:
- calculating a value for a first bit in the at least one flag when rendering the at least one frame buffer pixel to a frame buffer by:
- setting the first bit in the at least one flag, if a luminosity value of the at least one frame buffer pixel does not exceed a luminosity threshold and the object is opaque;
- resetting the first bit in the at least one flag, if the luminosity value of the at least one frame buffer pixel exceeds a luminosity threshold and the object is opaque;
- setting the first bit in the at least one flag, if a blended luminosity value of the at least one frame buffer pixel does not exceed a luminosity threshold and the object is non-opaque;
- and,
- resetting the first bit in the at least one flag, if the blended luminosity value of the at least one frame buffer pixel exceeds a luminosity threshold and the object is non-opaque;
- and
- identifying the at least one frame buffer pixel as a candidate for trapping, if the first bit in the flag associated with the at least one frame buffer pixel has been set.
A computer readable memory containing instructions for controlling a processor to perform steps in a method for identifying at least one frame buffer pixel associated with at least one display list object as a candidate for trapping, by associating at least one flag with the at least one frame buffer pixel, the method comprising the computer-implemented steps of:
- calculating a value for a first bit in the at least one flag when rendering the at least one frame buffer pixel to a frame buffer by:
- setting the first bit in the at least one flag, if a luminosity value of the at least one frame buffer pixel does not exceed a luminosity threshold and the object is opaque;
- resetting the first bit in the at least one flag, if the luminosity value of the at least one frame buffer pixel exceeds a luminosity threshold and the object is opaque;
- setting the first bit in the at least one flag, if a blended luminosity value of the at least one frame buffer pixel does not exceed a luminosity threshold and the object is non-opaque;
- and,
- resetting the first bit in the at least one flag, if the blended luminosity value of the at least one frame buffer pixel exceeds a luminosity threshold and the object is non-opaque;
- and
- identifying the at least one frame buffer pixel as a candidate for trapping, if the first bit in the flag associated with the at least one frame buffer pixel has been set.
Dependencies are inferred from the claim text.