US 5,506,944 AGranted

Method and apparatus for processing data for a visual-output device with reduced buffer memory requirements

AssigneeAdobe Systems Incorporated

InventorRonald S. Gentile

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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 programs 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.

Claims6

Dependent claims

A method of printing a two-dimensional page representation on a page having a maximum area, using a print system having at least one data memory coupled to at least one data processor and a print device coupled to at least one of the data processors, the page representation including a combination of text, graphic and image representation types, the method comprising the steps of:

inputting into a processor data defining the page representation as a combination of the different types of representations;
dividing the page into a plurality of contiguous parallel bands containing collectively the page representation;
identifying separate data for each band corresponding to the portion of the page representation contained in that band;
rasterizing the assigned data for each band;
determining the types of representations and boundaries of each type of representation contained in each band;
assigning the data for each representation type in each band to a region of that band corresponding to the boundaries of the representation of that type in that band;
providing a plurality of different algorithms for compressing data associated with corresponding different representation types;
providing at least one compression factor other than the representation type, which compression factor has a determinable value;
determining the value of each of the at least one compression factor;
selecting algorithms corresponding to the value of the compression factor and to the determined representation types and combinations of representation types for each region;
compressing the rasterized data for each region of each band with the selected algorithms;
storing the compressed data and associated information identifying the bands, representation types and combinations of representation types, and algorithms used to compress the associated data;
and
sequentially for each band:
reading and decompressing the corresponding stored data;
and
transmitting sequentially the decompressed data to the print device for printing the page representation.

14 more elements

A system for printing a two-dimensional page representation on a page having a maximum area, the page representation including a combination of text, graphic and image representation types, the system comprising:

a print device;
input means for inputting data defining the page representation as a combination of different types of representations;
data memory means for storing data representative of the page representation;
and
computer means including program memory means for storing computer program instructions including a plurality of different algorithms for compressing the defining data associated with corresponding different representation types and instructions defining at least one compression factor in addition to representation type and having a value determinable in association with a page representation, and processing means coupled to the input means, print device, data memory means and program memory means for executing the stored program instructions, the processing means being responsive to input data for (a) identifying separate data for each of a plurality of adjacent parallel bands containing collectively the page representation, the data identified for each band corresponding to the portion of the page representation contained in that band;
(b) rasterizing the assigned data for each band;
(c) determining the types of representations and boundaries of each type of representation contained in each band;
(e) determining the value of each of the at least one compression factor;
(f) assigning the data for each representation type in each band to a region of that band corresponding to the boundaries of the representation of that type in that band;
(g) selecting at least one algorithm for compressing the rasterized data for each region corresponding to the value of the at least one compression factor and to the determined representation type or combination of representation types;
(h) compressing the rasterized data for each band with the selected algorithms;
(f) storing the compressed data for each band and data identifying:
the bands, the regions of each band, the determined representation type or combination of representation types of each region, and the algorithms used to compress the data associated with each region;
and (g) after compressing the data, for each band, reading the corresponding stored data, decompressing the read data, and transmitting the decompressed data to the print device;
the print device being responsive to the transmitted data for printing the page representation.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/486,133Filed 6 Jun 1995 · division
Priority: 10 Nov 1992
Granted: 9 Apr 1996
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

H04N 1/41
Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof: bandwidth or redundancy reduction
G06K 15/00
Arrangements for producing a permanent visual presentation of the output data
G06K 15/181
Input data handling means: receiving print data characterized by its formatting, e.g. particular page description languages
G06K 15/1851
Using an intermediate representation, e.g. a list of graphical primitives: parted in a plurality of segments per page