Compressing and decompressing text files
First Claim
1. A method of creating a compressed text file stored in a computer memory in digital form, comprising:
- generating a full text file having characters formed into phrases, said characters being digital data;
generating a first level compressed text file from said full text file by replacing frequently occurring phrases in said first level compressed text file with a key phrase flag byte and an index byte; and
generating a second level compressed text file from said first level compressed text file by replacing each unique string of bytes in said first level compressed text file with a unique string of bits.
1 Assignment
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Accused Products
Abstract
A method of compressing a text file in digital form is disclosed. A full text file having characters formed into phrases is provided by an author. The characters are digitally represented by bytes. A first pass compression is sequentially followed by a second pass compression of the text which has previously been compressed. A third or fourth level compression is serially performed on the previously compressed text. For example, in a first pass, the text is run-length compressed. In a second pass, the compressed text is further compressed with key phrase compression. In a third pass, the compressed text is further compressed with Huffman compression. The compressed text is stored in a text file having a Huffman decode tree, a key phrase table, and a topic index. The data is decompressed in a single pass and provided one line at a time as an output. Sequential compressing of the text minimizes the storage space required for the file. Decompressing of the text is performed in a single pass. As a complete line is decompressed, it is output rapidly, providing full text to a user.
142 Citations
18 Claims
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1. A method of creating a compressed text file stored in a computer memory in digital form, comprising:
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generating a full text file having characters formed into phrases, said characters being digital data; generating a first level compressed text file from said full text file by replacing frequently occurring phrases in said first level compressed text file with a key phrase flag byte and an index byte; and generating a second level compressed text file from said first level compressed text file by replacing each unique string of bytes in said first level compressed text file with a unique string of bits. - View Dependent Claims (6)
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2. A method of creating a compressed text file stored in a computer memory in digital form, comprising:
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generating a full text file having characters formed into phrases, said characters being digital data; generating a first level compressed text file from said full text file by replacing digital data from said full text file with different digital data; generating a second level compressed text file from said first level compressed text file by replacing digital data from said first level compressed text file with different digital data to provide a second level compressed text file; and generating a third level compressed text file from said second level compressed text file by replacing digital data from said second level compressed text file with different digital data. - View Dependent Claims (16, 17)
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3. A method of creating a compressed text file stored in a computer memory in digital form, comprising:
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generating a full text file having characters formed into phrases, said characters being digital data; generating a first level compressed text file from said full text file by replacing digital data from said full text file with different digital data, the type of compression performed at the first level compression being selectable by a user from a plurality of choices; and generating a second level compressed text file from said first level compressed text file by replacing digital data from said first level compressed text file with different digital data to provide a compressed text file. - View Dependent Claims (18)
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4. A method of creating a compressed text file stored in a computer memory in digital form, comprising:
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generating a full text file having characters formed into phrases, said characters being digital data; generating a first level compressed text file from said full text file by replacing digital data from said full text file with different digital data; generating a second level compressed text file from said first level compressed text file by replacing digital data from said first level compressed text file with different digital data to provide a second level compressed text file; and generating a final compressed text file having a topic index, a context strings table, and said second level compressed text, wherein said topic index provides an address within said second level compressed text for obtaining selected information and said context strings table includes a listing of topics which are related to said information within said second level compressed text. - View Dependent Claims (5)
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7. A method of locating and decompressing text stored in the memory of a computer, comprising:
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inputting a first sample string of data representing a phrase; determining a first block of data within a compressed text file which relates to said sample string of data, said compressed text file including cross-reference data that defines topic relationships between data strings, said topic relationships being selectable by an author based on the context of said sample string as determined by said author; retrieving said compressed text file from memory; converting said compressed text file into a full format file ready for display on a computer monitor, said full format file including information for display to a viewer and cross-reference information; and displaying said information to said viewer, said cross-reference information providing an address to a second block of data related to a second sample string within said displayed information. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method of creating a compressed text file stored in a computer memory in digital form, comprising:
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generating a full text file having characters formed into phrases, said characters being digital data; generating a compressed text file containing said full text file in compressed data form; generating a context string table having full text data strings selected from said full text file; generating a topic index having addressed to different locations within said compressed text file; and combining said compressed text file, said context string table, and said topic index in a single data file to provide an accessible file that contains some full text of phrases, compressed text of the same selected phrases, and said topic index for facilitating access to user selectable portions of said compressed text. - View Dependent Claims (14, 15)
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Specification