Method and apparatus for processing data for a visual-output device with reduced buffer memory requirements
First Claim
1. A method of generating data for producing a page representation having an object representation with a first determinable characteristic, on a page by a visual-output device, comprising the steps of:
- receiving descriptive commands defining the page representation;
identifying at least a first region of the page having at least a portion of the object representation;
defining a first compression factor to have a value determined from the first characteristic of the object representation;
providing at least a first compression algorithm associated with a first value of the first compression factor and a second compression algorithm associated with a second value of the first compression factor;
determining the value of the first compression factor from the received descriptive commands;
selecting the algorithm based on the determined value of the first compression factor;
determining separate data for the portion of the object representation in the first region;
compressing at least a portion of the separate data with the selected algorithm;
storing the compressed data; and
after storing the compressed data, decompressing the stored data, and transmitting the decompressed data to the visual-output device.
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Accused Products
Abstract
A two-dimensional page representation to be printed has a combination of text, graphic and image representation types. A data memory stores data representative of the page representation. A program memory stores program instructions including a plurality of different algorithms for compressing data associated with corresponding different representation types and their combinations. A processor is coupled to the data and program memories for (a) identifying separate data for each of a plurality of regions containing collectively the page representation, with the data for each region corresponding to the portion of the page representation contained in that region; (b) determining the types of representations and boundaries of each type of representation and the combinations of types contained in each region; (c) rasterizing and compressing the data associated with the determined types of representations for each region with algorithms based on selected compression factors; (d) storing sequentially the compressed data for each region; and (e) when needed for printing, sequentially for each region, reading the corresponding stored data, decompressing the read data, and transmitting the decompressed data to the print device for printing.
139 Citations
17 Claims
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1. A method of generating data for producing a page representation having an object representation with a first determinable characteristic, on a page by a visual-output device, comprising the steps of:
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receiving descriptive commands defining the page representation; identifying at least a first region of the page having at least a portion of the object representation; defining a first compression factor to have a value determined from the first characteristic of the object representation; providing at least a first compression algorithm associated with a first value of the first compression factor and a second compression algorithm associated with a second value of the first compression factor; determining the value of the first compression factor from the received descriptive commands; selecting the algorithm based on the determined value of the first compression factor; determining separate data for the portion of the object representation in the first region; compressing at least a portion of the separate data with the selected algorithm; storing the compressed data; and after storing the compressed data, decompressing the stored data, and transmitting the decompressed data to the visual-output device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of generating data for producing a page representation having an object representation with a determinable characteristic, on a page by a visual-output device, comprising the steps of:
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dividing the page into a plurality of regions; receiving at least one descriptive command defining the page representation; providing a plurality of compression algorithms providing different compression characteristics; defining a compression factor to have a value determined from compression characteristics; progressively for respective regions, determining a current value of the compression factor from the characteristic of previously compressed data; selecting a compression algorithm based on the determined current value of the compression factor; and determining separate data for the portion of the object representation in the region; compressing the separate data with the selected algorithm; and storing the compressed data; and after storing the compressed data, decompressing the stored data, and transmitting the decompressed data to the visual-output device. - View Dependent Claims (14, 15, 16, 17)
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Specification