System and method for directed acuity segmentation resolution compression and decompression
First Claim
1. A hyperacuity printing system usable to render image data on a photosensitive recording medium, the image data being rendered as an array of pixels across the photosensitive recording medium in both a fastscan direction and an orthogonal slowscan direction, the hyperacuity printing system comprising:
- an output scanning device having a writing device that writes scan spots on the photosensitive recording medium;
transformation circuitry that transforms grayscale input image data into grayscale output image data, and a modulating device that receives the grayscale output image data from the transformation circuitry and that drives the output scanning device by intensity modulating scan spots in accordance with the grayscale output image data, wherein the transformation circuitry includes;
a halftoner that renders toneart;
a thresholder that renders non-continuous tone data, a resampling fabricator, coupled to the thresholder, that provides information about local rate of change of intensity of scan spots on the photosensitive recording medium in both fastscan and slowscan directions;
a segmenter that switches between the thresholder and the halftoner to provide grayscale output image data;
an encoder that discards image data corresponding to half of the pixels of the image data and compresses the remaining image data so that data corresponding to two non-continuous tone pixels are compressed into a single compressed-data-bitword; and
a data decompressor that decompresses a data in a single compressed-data-bitword to render the two pixels of non-continuous tone data and synthesizes data to render a third pixel of non-continuous tone data, the data decompressor being coupled to the thresholder.
4 Assignments
0 Petitions
Accused Products
Abstract
A compression and decompression system and process for optimally compressing and decompressing multibit per pixel image regions based on the type of data contained in the image region, e.g., whether the image region contains continuous tone data, including data to be halftoned, or non-continuous tone data, including antialiased text and lineart data. Segmented bytemap data blocks are processed to provide both low spatial resolution continuous tone data and high spatial resolution non-continuous tone data. However, the high spatial resolution non-continuous tone data is generated by quantizing and packing the high resolution bytes across an edge and discarding the high resolution bytes along the edge, i.e., the multibit data is discarded only in directions parallel to the edges of marks to be rendered in the image data. Additional information indicating the directions of the edges in the image data are stored to aid in decompression. Subsequently, during decompression, the non-continuous tone data is decompressed into a high spatial resolution bytemap by unpacking the high resolution across the edges and inferring the high resolution along the edges. The low spatial resolution continuous tone data are processed to provide a low spatial resolution continuous tone data bytemap. As a result of this compression and decompression method, the amount of memory necessary to store the non-continuous tone data is reduced to a quarter of the memory necessary to store a conventional high spatial resolution bytemap.
26 Citations
22 Claims
-
1. A hyperacuity printing system usable to render image data on a photosensitive recording medium, the image data being rendered as an array of pixels across the photosensitive recording medium in both a fastscan direction and an orthogonal slowscan direction, the hyperacuity printing system comprising:
-
an output scanning device having a writing device that writes scan spots on the photosensitive recording medium;
transformation circuitry that transforms grayscale input image data into grayscale output image data, and a modulating device that receives the grayscale output image data from the transformation circuitry and that drives the output scanning device by intensity modulating scan spots in accordance with the grayscale output image data, wherein the transformation circuitry includes;
a halftoner that renders toneart;
a thresholder that renders non-continuous tone data, a resampling fabricator, coupled to the thresholder, that provides information about local rate of change of intensity of scan spots on the photosensitive recording medium in both fastscan and slowscan directions;
a segmenter that switches between the thresholder and the halftoner to provide grayscale output image data;
an encoder that discards image data corresponding to half of the pixels of the image data and compresses the remaining image data so that data corresponding to two non-continuous tone pixels are compressed into a single compressed-data-bitword; and
a data decompressor that decompresses a data in a single compressed-data-bitword to render the two pixels of non-continuous tone data and synthesizes data to render a third pixel of non-continuous tone data, the data decompressor being coupled to the thresholder. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
Specification