Rendering images to lower bits per pixel formats using reduced numbers of registers

摘要

Methods and systems render higher bit per pixel contone images to lower bit formats using multiple registers of a SIMD processor. The rendering process uses a first register to maintain contone image values of all the pixels being simultaneously processed. A second register maintains a threshold value used during the conversion process. A third register maintains one value for the print ready format pixels (e.g., those having less bits per pixel), and a fourth register maintains the other value (e.g., 0) for the print ready format pixels. Also, a fifth register maintains the conversion error amount for all the pixels being simultaneously processed. Sixth through ninth registers maintain distributed conversion error amounts produced by the diffusing process (for different pixels being simultaneously processed); and a tenth register maintains the pixels in the print-ready format produced by the conversion for all the pixels being simultaneously processed.

主权项

1. A method comprising:
receiving a contone image having a first amount of bits per pixel into a single-instruction, multiple-data (SIMD) processor; converting said contone image to a print-ready format using said SIMD processor, said print ready format having a second amount of bits per pixel that is smaller than said first amount of bits per pixel, and said converting producing a conversion error amount for each pixel converted; combining pixels in said print-ready format produced by said converting into a print-ready image; and outputting said print-ready image, said converting comprising:
sequentially converting pixels of said contone image along scanlines of said contone image, said scanlines comprising pixels aligned in a processing direction in said contone image;diffusing a portion of said conversion error amount from a first pixel in a first scanline to at least one other pixel in said first scanline and to at least one other pixel in a second scanline immediately adjacent said first scanline; andsimultaneously converting pixels in immediately adjacent scanlines in a spaced manner that separates pixels being simultaneously processed, said converting simultaneously using different registers of said SIMD processor to maintain each of: pixel values of said contone image; a threshold value used during said converting; said conversion error amount for each pixel; distributed conversion error amounts produced by said diffusing; and said pixels in said print-ready format, in different registers.