US5040233A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data compression by discarding portions of data
Assignee: FFEI Ltd
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Filing: 1990-01-09
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Granted: 1991-08-13
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Expires: 2010-01-09
Abstract
Abstract A method of modifying a digital representation of an image in which digital data defines the content of pixels of the image. The method comprises a) determining whether a predetermined degree of compression can be achieved if data defining a block of pixels is compressed by applying a predetermined compression algorithm; and, if not, b) discarding a portion of the data in the block, and repeating steps a and b on the most recently modified block until the predetermined degree of compression is achieved, and generating a compressed version of the image.
Inventors
- 👤 Rex W. Davy
- 👤 David J. Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:45
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/41; H04N1/411; G; G06; G06T; G06T9/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
101 words
A machine implemented method of modifying a digital representation of an image in which digital data defines the content of pixels of the image, the method comprising a) determining whether a predetermined degree of compression can be achieved if data defining a block of pixels is compressed by applying a predetermined compression algorithm; and, if not, b) discarding a portion of the data in said block, and always repeating said step a on the most recently modified block and repeating said step b, if necessary, until the predetermined degree of compression is achieved, and generating a compressed version of said image.
Claim 2
Dependent Claim
101 words
A machine implemented method of modifying a digital representation of an image in which digital data defines the content of pixels of the image, the method comprising a) determining whether a predetermined degree of compression can be achieved if data defining a block of pixels is compressed by applying a predetermined compression algorithm; and, if not, b) discarding a portion of the data in said block, and always repeating said step a on the most recently modified block and repeating said step b, if necessary, until the predetermined degree of compression is achieved, and generating a compressed version of said image.
Claim 3
Dependent Claim
23 words
A method according to claim 1, wherein each said block of pixels comprises an integral number of lines of pixels defining said image.
Claim 4
Dependent Claim
20 words
A method according to claim 1, wherein step a) is performed by applying said predetermined algorithm to said digital data.
Claim 5
Dependent Claim
67 words
A method according to claim 1, wherein step a) comprises compressing data defining pairs of lines of pixels and comparing the resulting compressed data with the data needed to define a single line, step b being carried out if said compressed data has a greater volume than that needed to define a single line and in which step b comprises discarding one of said lines of data.
Claim 6
Dependent Claim
60 words
A method according to claim 1, wherein step a comprises compressing all said data in a block; and comparing the volume of the compressed data with that which it is required should be finally generated, step b comprising discarding a portion of said block of data if said volume of said compressed data is greater than that which is required.
Claim 7
Dependent Claim
43 words
A method according to claim 1, wherein step a) comprises determining whether a memory into which said compressed data is to be stored has been filled before all the original digital data corresponding to said block corresponding to the block has been compressed.
Claim 8
Dependent Claim
38 words
A method according to claim 1, wherein header information is generated for each compressed block defining the form of said data in said compressed block and defining those parts of the uncompressed data which need to be reconstituted.
Claim 9
Independent Claim
22 words
A method according to any of the preceding claims, wherein said compression algorithm applied in step a) is one dimensional runlength encoding.
Claim 10
Dependent Claim
106 words
Apparatus for modifying a digital representation of an image in which digital data defines the content of pixels of the image, the apparatus comprising processing means for carrying out the steps of a) determining whether a predetermined degree of compression can be achieved if data defining a block of pixels is compressed by applying a predetermined compression algorithm; and, if not, b) discarding a portion of the data in the block, and always repeating said step a on the most recently modified block and repeating said step b, if necessary, until the predetermined degree of compression is achieved, and generating a compressed version of the image.
Claim 11
Dependent Claim
106 words
Apparatus for modifying a digital representation of an image in which digital data defines the content of pixels of the image, the apparatus comprising processing means for carrying out the steps of a) determining whether a predetermined degree of compression can be achieved if data defining a block of pixels is compressed by applying a predetermined compression algorithm; and, if not, b) discarding a portion of the data in the block, and always repeating said step a on the most recently modified block and repeating said step b, if necessary, until the predetermined degree of compression is achieved, and generating a compressed version of the image.
Claim 12
Dependent Claim
20 words
Apparatus according to claim 9, further comprising a RAM into which said compressed data is loaded by said processing means.
Claim 13
Dependent Claim
19 words
Apparatus according to claim 10, wherein said RAM is capable of storing only two lines of said compressed data.
Claim 14
Dependent Claim
14 words
Apparatus according to claim 9, wherein said processing means comprises a suitably programmed microcomputer.
Claim 15
Dependent Claim
20 words
Method according to claim 1, wherein said digital data defines the content of the image pixels in bit map form.
Claim 16
Dependent Claim
20 words
Apparatus according to claim 9, wherein said digital data defines the content of the image pixels in bit map form.
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) | 1994-08-12 | 1995-02-11 | 1995-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-12 | 1999-02-11 | 1999-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-12 | 2003-02-11 | 2003-08-13 | $7700.00 | Window Closed / Lapsed |