US4568983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image data compression/decompression
Assignee: Kodak Versamark Inc
•
Filing: 1983-12-07
•
Granted: 1986-02-04
•
Expires: 2003-12-07
Abstract
Abstract Scanned image data is assembled to represent scanned strips of a document each strip comprising a plurality of scanned lines. The lines of each strip are read in parallel to form data words defining columns of the scanned strips. The data words are encoded by means of Huffman and run-length coding to generate fixed-length coded words which are concatenated to represent the document. Each strip of coded words is reviewed and uncoded data is substituted for coded data in the event the coded data exceeds the uncoded data. Text data and continuous tone data are encoded using different encoding techniques due to their varying characteristics. Synchronization words are used to prefix all coded data strips; to prefix and suffix all uncoded data strips; to define all white and all black strips; and, to indicate changes in data type, i.e., text to continuous tone or vice versa. At least the first and the last data word of each encoded strip are defined as text so that decoding can commence using text decoding techniques. The utilization of fixed-length coded words, the forced definition of at least the first and last data word of each strip as text, and the synchronization code words permit bidirectional decoding of encoded data blocks.
Inventors
- 👤 Thomas W. Bobick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:26
CPC Classifications
G; G06; G06T; G06T9/00; G06T9/005; H; H04; H04N; H04N1/00; H04N1/41; H04N1/411; H04N1/413; H04N1/415
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
195 words
A method of encoding digital data representative of a document to be duplicated and obtained by scanning said document, said digital data including both text data and continuous tone data and said method comprising the steps of: assembling said digital data into scanned strips of said document with each scanned strip comprising a plurality of scan lines of said document; reading the scan lines in parallel to form data words defining columns of said scanned strips; counting the number of consecutive data words in each scanned strip which are identical to one another to determine the run lengths of said identical data words; encoding each run of data words read and the corresponding run length into a fixed length coded word, said continuous tone data being encoded such that at least some of said data words define blocks of said scanned strips each block comprising at least two individual columns of a scanned strip; concatenating all fixed length coded words to represent said document; prefixing a synchronization word to each encoded scanned strip; and inserting additional synchronization words at any transition of data words from text to continuous tone or from continuous tone to text.
Claim 2
Independent Claim
195 words
A method of encoding digital data representative of a document to be duplicated and obtained by scanning said document, said digital data including both text data and continuous tone data and said method comprising the steps of: assembling said digital data into scanned strips of said document with each scanned strip comprising a plurality of scan lines of said document; reading the scan lines in parallel to form data words defining columns of said scanned strips; counting the number of consecutive data words in each scanned strip which are identical to one another to determine the run lengths of said identical data words; encoding each run of data words read and the corresponding run length into a fixed length coded word, said continuous tone data being encoded such that at least some of said data words define blocks of said scanned strips each block comprising at least two individual columns of a scanned strip; concatenating all fixed length coded words to represent said document; prefixing a synchronization word to each encoded scanned strip; and inserting additional synchronization words at any transition of data words from text to continuous tone or from continuous tone to text.
Claim 3
Dependent Claim
45 words
A method of encoding digital data as claimed in claim 1 wherein at least the first and last data words of each scanned strip are defined as text data and the prefixing synchronization word includes the identification of the strip as beginning with text data.
Claim 4
Dependent Claim
53 words
A method of encoding digital data as claimed in claim 1 further comprising the steps of: determining whether each scanned strip is all white or all black prior to encoding the strip; and inserting a synchronization word to identify each all white or all black strip whereby coding of such strips is unnecessary.
Claim 5
Dependent Claim
50 words
A method of encoding digital data as claimed in claim 1 further comprising the steps of: reviewing the coded words generated to represent each scanned strip; and substituting uncoded scanned strip data for generated coded words in the event that the generated coded words exceed the uncoded scanned strip data.
Claim 6
Dependent Claim
33 words
A method of encoding digital data as claimed in claim 4 wherein the prefixing synchronization word identifies the data strip as uncompressed data and a similar synchronization word suffixes each uncompressed data strip.
Claim 7
Independent Claim
247 words
A method of encoding digital data representative of a document to be duplicated and obtained by scanning said document, said data representing either text data or continuous tone data and said method resulting in compressed data which can be decompressed in either direction to recover the original digital data and comprising the steps of: assembling said digital data into scanned strips of said document with each scanned strip comprising a plurality of scan lines of said document; reading the scan lines of said scanned strips in parallel to form data words defining columns of said scanned strips; defining at least the first and last data words of each scanned strip as text data; counting the number of consecutive data words in each scanned strip which are identical to one another to determine the run lengths of said identical data words; encoding each run of data words read and the corresponding run length into fixed length coded words; concatenating all fixed length code words for each scanned strip to form coded scanned strips; reviewing each coded scanned strip; substituting uncoded scanned strip data for any coded scanned strip which exceeds its corresponding uncoded scanned strip data; concatenating all coded and uncoded scanned strips to form a coded representation of said document; inserting synchronization words before each coded scanned strip and before and after each uncoded scanned strip; and inserting synchronization words into said coded scanned strips to separate text data from continuous tone data and continuous tone data.
Claim 8
Independent Claim
247 words
A method of encoding digital data representative of a document to be duplicated and obtained by scanning said document, said data representing either text data or continuous tone data and said method resulting in compressed data which can be decompressed in either direction to recover the original digital data and comprising the steps of: assembling said digital data into scanned strips of said document with each scanned strip comprising a plurality of scan lines of said document; reading the scan lines of said scanned strips in parallel to form data words defining columns of said scanned strips; defining at least the first and last data words of each scanned strip as text data; counting the number of consecutive data words in each scanned strip which are identical to one another to determine the run lengths of said identical data words; encoding each run of data words read and the corresponding run length into fixed length coded words; concatenating all fixed length code words for each scanned strip to form coded scanned strips; reviewing each coded scanned strip; substituting uncoded scanned strip data for any coded scanned strip which exceeds its corresponding uncoded scanned strip data; concatenating all coded and uncoded scanned strips to form a coded representation of said document; inserting synchronization words before each coded scanned strip and before and after each uncoded scanned strip; and inserting synchronization words into said coded scanned strips to separate text data from continuous tone data and continuous tone data.
Claim 9
Independent Claim
142 words
A method of handling digital data representative of a document to be duplicated and obtained by scanning said document comprising the steps of: assembling said digital data into scanned strips of said document with each scanned strip comprising a plurality of scanned lines of said document; reading the scanned lines in parallel to form data words defining columns of said scanned strips; counting the number of consecutive data words in each scanned strip which are identical to one another to determine the run length of said identical words; encoding each run of data words read and the corresponding run length into a fixed-length coded word; storing all fixed-length coded words in a concatenated form to represent said document; reading said concatenated fixed-length coded words; and decoding said fixed-length coded words to obtain the digital data representative of the document to be duplicated.
Claim 10
Independent Claim
142 words
A method of handling digital data representative of a document to be duplicated and obtained by scanning said document comprising the steps of: assembling said digital data into scanned strips of said document with each scanned strip comprising a plurality of scanned lines of said document; reading the scanned lines in parallel to form data words defining columns of said scanned strips; counting the number of consecutive data words in each scanned strip which are identical to one another to determine the run length of said identical words; encoding each run of data words read and the corresponding run length into a fixed-length coded word; storing all fixed-length coded words in a concatenated form to represent said document; reading said concatenated fixed-length coded words; and decoding said fixed-length coded words to obtain the digital data representative of the document to be duplicated.
Claim 11
Dependent Claim
157 words
A method of handling digital data as claimed in claim 7 wherein said digital data includes both text data and continuous tone data, said continuous tone data being encoded such that at least some of said data words define blocks of said scanned strips, each block comprising at least two individual columns of a scanned strip, and further comprising the steps of: defining at least the first and last data words of each scanned strip as being text data; prefixing a synchronization word to each encoded scanned strip, said synchronization word including the identification of the strip as beginning with text data; and inserting synchronization words between data words representing text and data words representing continuous tone, said reading step being either from the first encoded data word to the last or from the last encoded data word to the first whereby the encoded data can be decoded in either direction to recover the original digital data.
Claim 12
Dependent Claim
79 words
A method of handling digital data as claimed in claim 8 further comprising the steps of: reviewing the coded words generated to represent each scanned strip; substituting uncoded scanned strip data for generated coded words in the event that the generated coded words exceed the uncoded scanned strip data; changing the prefixing synchronization word to identify the data strip as uncompressed data; and suffixing a synchronization word to each uncompressed data strip to identify the strip as uncompressed data.
Claim 13
Dependent Claim
129 words
Apparatus for encoding digital data representative of a document to be duplicated and obtained by scanning said document, said apparatus comprising: buffer means for assembling said digital data into scanned strips of said document with each scanned strip comprising a plurality of scanned lines of said document; pattern recognition means connected to said buffer means for identifying data words representative of columns of said scanned strips; counter means responsive to said pattern recognition means for determining the run length of consecutive data words in each scanned strip which are identical to one another; encoder means responsive to the identified data words and run lengths for forming fixed-length coded words representative thereof; and output buffer means for concatenating all fixed-length coded words to form a coded representation of said document.
Claim 14
Dependent Claim
129 words
Apparatus for encoding digital data representative of a document to be duplicated and obtained by scanning said document, said apparatus comprising: buffer means for assembling said digital data into scanned strips of said document with each scanned strip comprising a plurality of scanned lines of said document; pattern recognition means connected to said buffer means for identifying data words representative of columns of said scanned strips; counter means responsive to said pattern recognition means for determining the run length of consecutive data words in each scanned strip which are identical to one another; encoder means responsive to the identified data words and run lengths for forming fixed-length coded words representative thereof; and output buffer means for concatenating all fixed-length coded words to form a coded representation of said document.
Claim 15
Dependent Claim
52 words
Apparatus for encoding digital data as claimed in claim 10 wherein said pattern recognition means comprises: text pattern recognition means for identifying data words representative of single columns of said scanned strips; and continuous tone pattern recognition means for identifying data words representative of at least two columns of said scanned strips.
Claim 16
Dependent Claim
48 words
Apparatus for encoding digital data as claimed in claim 11 further comprising control means for inserting synchronization code words into said coded representation of said document to identify the beginning of each coded scanned strip and to separate data representative of text from data representative of continuous tone.
Claim 17
Dependent Claim
68 words
Apparatus for encoding digital data as claimed in claim 12 wherein said control means further provides for reviewing each coded scanned strip data and for substantially uncoded scanned strip data for coded scanned strip data if the uncoded scanned strip data is less, said control means also inserting synchronization code words at the beginning and end of each strip of uncoded data to identify such strips as uncoded.
Claim 18
Independent Claim
140 words
A method of encoding digital data representative of a document to be duplicated and obtained by scanning said document comprising the steps of: assembling said digital data into scanned strips of said document with each scanned strip comprising a plurality of scan lines of said document; reading the scan lines in parallel to form data words defining columns of said scanned strips; counting the number of consecutive data words in each scanned strip which are identical to one another to determine the run lengths of said identical data words; encoding runs of data words read and the corresponding run lengths into fixed length coded words, said run lengths being equal to or less than one of a number of maximum run lengths associated with said fixed length coded words; and concatenating all fixed length coded words to represent said document.
Claim 19
Independent Claim
140 words
A method of encoding digital data representative of a document to be duplicated and obtained by scanning said document comprising the steps of: assembling said digital data into scanned strips of said document with each scanned strip comprising a plurality of scan lines of said document; reading the scan lines in parallel to form data words defining columns of said scanned strips; counting the number of consecutive data words in each scanned strip which are identical to one another to determine the run lengths of said identical data words; encoding runs of data words read and the corresponding run lengths into fixed length coded words, said run lengths being equal to or less than one of a number of maximum run lengths associated with said fixed length coded words; and concatenating all fixed length coded words to represent said document.
Claim 20
Dependent Claim
25 words
A method of encoding digital data as claimed in claim 14 further comprising the step of prefixing a synchronization word to each encoded scanned strip.
Claim 21
Dependent Claim
83 words
A method of encoding digital data as claimed in claim 15 wherein said digital data includes both text data and continuous tone data, said continuous tone data being encoded such that at least some of said data words define blocks of said scanned strips each block comprising at least two individual columns of a scanned strip and further comprising the step of inserting additional synchronization words at any transition of data words from text to continuous tone or from continuous tone to text.
References Cited (Backward Citations)
US2953638A
Cited
US4135214A
Cited
US3916095A
Cited
US3992572A
Cited
US4048656A
Cited
US4070694A
Cited
US4121259A
Cited
US4376933A
Cited
US4327379A
Cited
US4386373A
Cited
US4499499A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |