US4355306A
Expired / Lapsed
US
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Dynamic stack data compression and decompression system
Assignee: International Business Machines Corp
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Filing: 1981-01-30
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Granted: 1982-10-19
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Expires: 2001-01-30
Abstract
Abstract A system for encoding images by assigning variable-length code words to fixed positions in a dynamic stack. Each position in the dynamic stack is occupied by a representation of an encodable image feature, such as a run-length or a vertical correlation. These codes are arranged in order of their respective frequencies of occurrence. The order in which these features are stacked is varied dynamically by the system, in accordance with their respective frequencies of occurrence and a predetermined scheme. Thus, the system can adapt to different types of documents being scanned, or to changes of scanning resolution. A relationship exists between the code words and the stack positions, which are not permanently assigned to specific image features. This arrangement ensures that the lengths of code words will be inversely related to their frequencies of occurrence under all conditions.
Inventors
- 👤 Joan L. Mitchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:35
CPC Classifications
H; H03; H03M; H03M7/00; H03M7/30; H03M7/40; H03M7/42; G; G06; G06T; G06T9/00; G06T9/005; H04; H04N; H04N1/00; H04N1/41; H04N1/411; H04N1/413; H04N1/417; H04N1/4175
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
155 words
In a data compression apparatus wherein an image is scanned line-by-line to sense the characteristics thereof and the positions at which such characteristics are located, the combination of: first encoding means for producing digital representations of the sensed characteristics and their respective relationships to other characteristics; at least one stack each having a plurality of addressable storage positions therein for storing a subset of said digital representations as they are produced by said first encoding means; means for determining the location in at least one of said stacks, of a digital representation corresponding to a currently sensed characteristic; second encoding means responsive to said location determining means for generating a coded representation of said stack location, which is provided to a utilization means; control means functioning in response to each determination made by said location determining means for rearranging said digital representations in at least one of said stacks in accordance with a predetermined scheme.
Claim 2
Dependent Claim
155 words
In a data compression apparatus wherein an image is scanned line-by-line to sense the characteristics thereof and the positions at which such characteristics are located, the combination of: first encoding means for producing digital representations of the sensed characteristics and their respective relationships to other characteristics; at least one stack each having a plurality of addressable storage positions therein for storing a subset of said digital representations as they are produced by said first encoding means; means for determining the location in at least one of said stacks, of a digital representation corresponding to a currently sensed characteristic; second encoding means responsive to said location determining means for generating a coded representation of said stack location, which is provided to a utilization means; control means functioning in response to each determination made by said location determining means for rearranging said digital representations in at least one of said stacks in accordance with a predetermined scheme.
Claim 3
Dependent Claim
23 words
The apparatus as defined in claim 1 wherein said at least one stack comprises: a first color stack and a second color stack.
Claim 4
Dependent Claim
40 words
The apparatus as defined in claim 2 further comprising: means for examining said characteristics and determining which of said first and second color stacks are to be rearranged and which locations are to be utilized by said second encoding means.
Claim 5
Dependent Claim
40 words
The apparatus as defined in claim 3 wherein said second encoding means further comprises: pattern recognition means for examining said digital representations from said first encoding means and the coded representation from said second encoding means, and identifying repeating patterns.
Claim 6
Dependent Claim
30 words
The apparatus as defined in claim 4 wherein said at least one stack comprises: in addition to said first and second color stacks a first and second color feature stacks.
Claim 7
Dependent Claim
25 words
The apparatus as defined in claim 5 wherein said first and second color feature stacks contain locations from said first and second color stacks, respectively.
Claim 8
Dependent Claim
18 words
The apparatus as defined in claim 6 wherein said predetermined scheme for rearranging locations is move up one.
Claim 9
Dependent Claim
28 words
The apparatus as defined in claim 1 wherein the relationships identified are multi-dimensional and at least one of these dimensions relates to at least one previously scanned line.
Claim 10
Dependent Claim
18 words
The apparatus as defined in claim 1 wherein said predetermined scheme for rearranging locations is move up one.
Claim 11
Dependent Claim
19 words
The apparatus as defined in claim 1 wherein said predetermined scheme for rearranging locations is move up half way.
Claim 12
Dependent Claim
18 words
The apparatus as defined in claim 1 wherein said predetermined scheme for rearranging locations is move to top.
References Cited (Backward Citations)
US3828319A
Cited
US3694813A
Cited
US3701108A
Cited
US3878513A
Cited
US3833900A
Cited
US4029947A
Cited
US3916385A
Cited
US3967247A
Cited
US3958228A
Cited
US4121258A
Cited
UST985005I4
Cited
US4258392A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-18 | 1986-04-19 | 1986-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-18 | 1990-04-19 | 1990-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-18 | 1994-04-19 | 1994-10-19 | $7700.00 | Window Closed / Lapsed |