US4712140A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image reduction method
Assignee: International Business Machines Corp
•
Filing: 1986-03-17
•
Granted: 1987-12-08
•
Expires: 2006-03-17
Abstract
Abstract A binary image is reduced in size by a method including the steps of: storing the image in bit sequence; dividing the image into transposable blocks; transposing by look up table, for each block having any nonzero data, each group of 6 bits along a first axis to a group of 5 bits; transposing by look up table, for each block having any nonzero data, each group of 6 bits along a second axis to a group of 5 bits; storing said transposed blocks.
Inventors
- 👤 Frederick C. Mintzer
- 👤 Karen L. Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:14
CPC Classifications
G; G06; G06T; G06T3/00; G06T3/60; G06T3/602; H; H04; H04N; H04N1/00; H04N1/387; H04N1/393; H04N1/3935
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
104 words
A method for reducing the size of a binary image in a general-purpose computer comprising the steps of: storing said binary image in bit sequence in said computer dividing said image into transposable blocks of n×i bits transposing for each block, each string of n bits along a first axis to a string of m bits along a second axis where m is less than n; transposing for each transposed block, each string of i bits along said first axis to a string of j bits along said second axis, where j is less than or equal to i; and storing said transposed blocks.
Claim 2
Independent Claim
104 words
A method for reducing the size of a binary image in a general-purpose computer comprising the steps of: storing said binary image in bit sequence in said computer dividing said image into transposable blocks of n×i bits transposing for each block, each string of n bits along a first axis to a string of m bits along a second axis where m is less than n; transposing for each transposed block, each string of i bits along said first axis to a string of j bits along said second axis, where j is less than or equal to i; and storing said transposed blocks.
Claim 3
Dependent Claim
15 words
A method according to claim 1 wherein said transposing steps are accomplished by table lookup.
Claim 4
Dependent Claim
14 words
A method according to claim 1 wherein n equals 6 and m equals 5.
Claim 5
Dependent Claim
22 words
A method according to claim 1 further comprising the step of testing each block for all bits of the same binary value.
Claim 6
Dependent Claim
25 words
A method according to claim 4 further comprising the step of omitting the transposing of each block having all bits of the same binary value.
Claim 7
Dependent Claim
10 words
A method according to claim 1 wherein n=i and m=j.
Claim 8
Dependent Claim
41 words
A method according to claim 2 wherein said table lookup for said block transposing step comprises: a first lookup table and i-1 successive lookup tables with each of said successive lookup tables having their values shifted successively left by one bit.
Claim 9
Dependent Claim
42 words
A method according to claim 2 wherein said table lookup for said transposed block transposing step comprises: a first lookup table and m-1 successive lookup tables with each of said successive lookup tables having their values shifted successively left by one bit.
Claim 10
Dependent Claim
109 words
A method according to claim 3 wherein said transposing of each string of n bits comprises the steps of: removing the third bit in said string if no run is destroyed thereby; otherwise, removing one bit from any run in a string longer than all the other runs; otherwise, if there are two two-bit runs not spaced equidistant from the center of the string, shortening the two-bit run closer to the center of the string by one bit; otherwise, if there are two two-bit runs of different color equidistant from said center, shortening the run of zero bits by one bit; otherwise, removing the zero bit nearest said center.
Claim 11
Dependent Claim
105 words
A computerized system for reducing the size of a binary image comprising: means for storing said binary image in bit sequence; means for dividing said image into transposable blocks of n×i bits; means for transposing in each block, a string of n bits along a first axis to a string of m bits along a second axis, where m is less than n; means for transposing for each transposed block, each string of i bits along said first axis to a string of j bits along said second axis, where j is less than or equal to i; and means for storing said transposed blocks.
Claim 12
Dependent Claim
105 words
A computerized system for reducing the size of a binary image comprising: means for storing said binary image in bit sequence; means for dividing said image into transposable blocks of n×i bits; means for transposing in each block, a string of n bits along a first axis to a string of m bits along a second axis, where m is less than n; means for transposing for each transposed block, each string of i bits along said first axis to a string of j bits along said second axis, where j is less than or equal to i; and means for storing said transposed blocks.
Claim 13
Dependent Claim
21 words
A system as in claim 10 further comprising means for testing each block for all bits of the same binary value.
Claim 14
Dependent Claim
24 words
A system as in claim 11 further comprising means for omitting the transposition of each block having all bits of the same binary value.
Claim 15
Dependent Claim
18 words
A system as in claim 10 wherein both of said transposing means comprise a plurality of lookup tables.
Claim 16
Dependent Claim
41 words
A system as in claim 13 wherein said lookup tables for said block transposing means comprise: a first lookup table and i-1 successive lookup tables with each of said successive lookup tables having their values shifted successively left by one bit.
Claim 17
Dependent Claim
42 words
A system as in claim 13 wherin said lookup tables for said transposed block transposing means comprise: a first lookup table and m-1 successive lookup tables with each of said successive lookup tables having their values shifted successively left by one bit.
Claim 18
Independent Claim
102 words
A method for reducing the size of a binary image in a general-purpose computer comprising the steps of: storing said binary image in bit sequence in said computer; dividing said image into transposable blocks of bits having i bits on one axis and n bits on the other axis; transposing each block by converting the string of n bits along said other axis to a string of m bits along said one axis, where m is less than n; transposing each transposed block by converting the string of m bits to said other axis; and storing said blocks after the foregoing transpositions.
Claim 19
Independent Claim
102 words
A method for reducing the size of a binary image in a general-purpose computer comprising the steps of: storing said binary image in bit sequence in said computer; dividing said image into transposable blocks of bits having i bits on one axis and n bits on the other axis; transposing each block by converting the string of n bits along said other axis to a string of m bits along said one axis, where m is less than n; transposing each transposed block by converting the string of m bits to said other axis; and storing said blocks after the foregoing transpositions.
Claim 20
Dependent Claim
38 words
A method as in claim 16, further comprising the step of: converting each string of i bits to a string of j bits during the transposition of each of said transposed blocks, where j is less than i.
Claim 21
Dependent Claim
20 words
A method as in claim 16, wherein blocks consisting of bits having all the same binary value are not transposed.
Claim 22
Dependent Claim
106 words
A method as in claim 16, wherein said transposing of each string of n bits comprises: removing bit n/2, where n/2=the nearest integer, in the string, if no run is destroyed thereby; otherwise, removing one bit from the longest run in the string, if there is one run that is longer than all the other runs; otherwise, shortening by one bit the run of maximum length closest to the center of the string, if such a run exists; otherwise, if there are two runs of maximum length and opposite color equidistant from the center of the string, shortening the run of zero bits by one bit.
Claim 23
Dependent Claim
46 words
A method according to claim 16, wherein said transposing steps are accomplished by table lookup comprising a first lookup table and the greater of i-1 and m-1 successive lookup tables with each of said successive lookup tables having their values shifted successively left by one bit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-12-07 | 1991-06-08 | 1991-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-07 | 1995-06-08 | 1995-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-07 | 1999-06-08 | 1999-12-08 | $7700.00 | Window Closed / Lapsed |