Digital printing system and process using adaptive compression
AssigneeXionics Document Technologies, Inc.
InventorsCraig C. Cook, Thomas P. Blumer, Theodore B. Packard, Geoffrey A. Dreher, Thomas A. Schuneman
Life of this patent
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Abstract
A system and process for digital printing divides an image area into segments, defines display lists for each segment, generates graphic primitives from page description language commands, stores the graphic primitives in the display lists, and adaptively compresses and converts the contents of display lists as memory requirements exceed available memory capacity. Display lists contain either uncompressed pixel representations, compressed pixel representations, graphic primitives, or combinations of the foregoing.
Claims8
A computer-implemented process of drawing an image on an imaging area of a computer output device in response to commands generated by a computer, the process comprising:
- spatially dividing the imaging area into a plurality of sections;
- creating a plurality of display lists, each of the display lists corresponding to one of the sections;
- determining, for a current one of the commands, a subset of the sections to which said current command pertains;
- generating a graphic primitive for a selected one of the subset of sections;
- updating with said graphic primitive one of said plurality of display lists corresponding to said selected section;
- adaptively reducing a subset of said plurality of display lists responsive to a memory requirement exceeding an available memory capacity by determining a type for each display list responsive to presence therein of a pixel representation and responsive to presence therein of a graphic primitive representation;
- and
- drawing said image responsive to said updated display list.
A computer-implemented process of drawing an image on an imaging area of a computer output device in response to commands generated by a computer, the process comprising:
- spatially dividing the imaging area into a plurality of sections;
- creating a plurality of display lists, each of the display lists corresponding to one of the sections;
- determining, for a current one of the commands, a subset of the sections to which said current command pertains;
- generating a graphic primitive for a selected one of the subset of sections;
- determining a memory requirement for storing said graphic primitive in one of said display lists corresponding to said selected section;
- adaptively reducing a subset of said plurality of display lists responsive to the memory requirements exceeding an available memory capacity by determining a type for each display list responsive to presence therein of a pixel representation and responsive to presence therein of a graphic primitive representation;
- updating, subsequent to said step of adaptively compressing, said one display list with said graphic primitive;
- and
- drawing said image responsive to said updated display list.
A system for displaying an image defined by image data, the system, comprising:
- an interpreter disposed to receive the image data and produce graphic primitive and pixel representations therefrom;
- a display list storage area including a plurality of segments corresponding to spatially distinct sections of the image;
- a display list generator coupled to the interpreter and to the display list storage area and generating for storage in the display list storage area display lists from said representations;
- a memory manager coupled to the display list generator and disposed to compare storage requirements for display lists generated by the display list generator with available storage space in the display list storage area;
- a compression processor coupled to the memory manager and the display list storage area for adaptively compressing display lists in the display list storage area in response the memory manager indicating storage requirements for display lists exceeding available storage space in the display list storage area, the compression processor disposed to analyze display lists to determine inclusion therein of pixel and graphic primitive components;
- the compression processor further disposed to selectively decompress, convert between graphic primitive and pixel form, combine, and compress the components of display lists in response to inclusion therein of the components to increase available storage space in display list storage area;
- a display list processor coupled to the display list storage area to retrieve display lists from the display list storage area and to produce pixel representations therefrom;
- and
- an output device coupled to the display list processor for drawing the image in response to the pixel representations produced by the display list processor.
Dependencies are inferred from the claim text.