US6014467A
Expired / Lapsed
US
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High speed, high precision image compression
Assignee: Fujifilm Holdings Corp
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Filing: 1997-09-17
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Granted: 2000-01-11
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Expires: 2017-09-17
Abstract
Abstract An image compression system having: an image data supply unit for supplying image data divided into a block unit; a DCT unit for discrete-cosine-transforming the image data in the block unit supplied from the image data supply unit to generate DCT coefficients in the block unit; a coded data generating unit for successively generating coded data of the DCT coefficients at first and second compression factors each time the DCT coefficients of one block are generated by the DCT unit; a counter unit for accumulating the amount of coded data generated at each of the first and second compression factors by the coded data generating unit; and a compression factor estimating unit for estimating a compression factor suitable for generating coded data of a target amount, in accordance with the amounts of coded data accumulated at the first and second compression factors by the counter unit.
Inventors
- 👤 Masanari Asano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:57
CPC Classifications
G; G06; G06T; G06T9/00; G06T9/007
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
159 words
An image compression system comprising: image data supply means for supplying image data divided into a plurality of blocks; DCT means for discrete-cosine-transforming the image data in each block of said plurality of blocks supplied from said image data supply means to generate DCT coefficients in each block; coded data generating means for successively generating coded data of the DCT coefficients of each block of said plurality of blocks at first and second standard predetermined compression factors while DCT coefficients of a succeeding block are generated by said DCT means; a counter unit for accumulating the amount of coded data generated at each of the first and second standard predetermined compression factors by said coded data generating means; and compression factor estimating means for estimating a compression factor suitable for generating coded data of a target amount in accordance with the amounts of coded data accumulated at the first and second standard predetermined compression factors by said counter unit.
Claim 2
Dependent Claim
159 words
An image compression system comprising: image data supply means for supplying image data divided into a plurality of blocks; DCT means for discrete-cosine-transforming the image data in each block of said plurality of blocks supplied from said image data supply means to generate DCT coefficients in each block; coded data generating means for successively generating coded data of the DCT coefficients of each block of said plurality of blocks at first and second standard predetermined compression factors while DCT coefficients of a succeeding block are generated by said DCT means; a counter unit for accumulating the amount of coded data generated at each of the first and second standard predetermined compression factors by said coded data generating means; and compression factor estimating means for estimating a compression factor suitable for generating coded data of a target amount in accordance with the amounts of coded data accumulated at the first and second standard predetermined compression factors by said counter unit.
Claim 3
Dependent Claim
33 words
An image compression system according to claim 1, further comprising means for instructing said coded data generating means to generate coded data at the compression factor estimated by said compression factor estimating means.
Claim 4
Dependent Claim
49 words
An image compression system according to claim 1, wherein said coded data generating means includes quantizing means for generating the coded data at the first and second compression factors by quantizing the DCT coefficients of each block of said plurality of blocks by using first and second quantization tables.
Claim 5
Dependent Claim
64 words
An image compression system according to claim 1, wherein said DCT means successively discrete-cosine-transforms the image data in each block of said plurality of blocks, and before said DCT means discrete-cosine-transforms the image data of a first block, said coded data generating means completes the generation of coded data of a preceding block to said first block at the first and second compression factors.
Claim 6
Dependent Claim
29 words
An image compression system according to claim 1, wherein said image data supply means supplies the image data of a sample block selected from blocks of one frame image.
Claim 7
Dependent Claim
64 words
An image compression system according to claim 1, wherein said counter unit includes first and second registers, the amount of coded data of each block generated at the first compression factor is cumulatively counted and stored in the first register, and the amount of coded data of each block generated at the second compression factor is cumulatively counted and stored in the second register.
Claim 8
Dependent Claim
32 words
An image compression system according to claim 3, wherein said quantizing means generates the first and second quantization tables by multiplying a standard quantization table by first and second scale factors, respectively.
Claim 9
Dependent Claim
35 words
An image compression system according to claim 3, wherein said coded data generating means includes coding means for executing Huffman coding after the DCT coefficients of each block of said plurality of blocks are quantized.
Claim 10
Dependent Claim
49 words
An image compression system according to claim 4, wherein said coded data generating means includes quantizing means for generating the coded data at the first and second compression factors by quantizing the DCT coefficients of each block of said plurality of blocks by using first and second quantization tables.
Claim 11
Dependent Claim
36 words
An image compression system according to claim 5, further comprising means for instructing said coded data generating means to generate coded data of all blocks at the compression factor estimated by said compression factor estimating means.
Claim 12
Dependent Claim
18 words
An image compression system according to claim 8, wherein said coding means includes means for executing run-length coding.
Claim 13
Dependent Claim
98 words
An image compression method comprising the steps of: (a) generating DCT coefficients of a first block by discrete-cosine-transforming-image data of the first block; (b) after the DCT coefficients of the first block are generated, generating DCT coefficients of a second block by discrete-cosine-transforming image data of the second block; (c) after the DCT coefficients of the first block are generated, while the DCT coefficients of the second block are generated, generating coded data of the DCT coefficients of the first block at a first standard predetermined compression factor and in succession at a second standard predetermined compression factor.
Claim 14
Dependent Claim
98 words
An image compression method comprising the steps of: (a) generating DCT coefficients of a first block by discrete-cosine-transforming-image data of the first block; (b) after the DCT coefficients of the first block are generated, generating DCT coefficients of a second block by discrete-cosine-transforming image data of the second block; (c) after the DCT coefficients of the first block are generated, while the DCT coefficients of the second block are generated, generating coded data of the DCT coefficients of the first block at a first standard predetermined compression factor and in succession at a second standard predetermined compression factor.
Claim 15
Dependent Claim
73 words
An image compression method according to claim 12, further comprising the steps of: (d) accumulating the amount of coded data generated at each of the first and second compression factors, for all blocks constituting one frame of the image data; and (e) estimating a compression factor suitable for generating coded data of a target data amount, in accordance with the accumulated amounts of coded data generated at the first and second compression factors.
Claim 16
Dependent Claim
34 words
An image compression method according to claim 12, wherein said step (c) generates the coded data at the first and second compression factors by quantizing the DCT coefficients by first and second quantization tables.
Claim 17
Dependent Claim
20 words
An image compression method according to claim 12, wherein said step (c) is executed in parallel with said step (b).
Claim 18
Dependent Claim
35 words
An image compression method according to claim 12, wherein said steps (a) and (b) executes discrete cosine transformation by using sample blocks selected from blocks of one frame image as the first and second blocks.
Claim 19
Dependent Claim
29 words
An image compression method according to claim 13, further comprising the step of: (f) generating coded data of all blocks of the image data at the estimated compression factor.
Claim 20
Dependent Claim
57 words
An image compression method according to claim 13, wherein said step (d) cumulatively counts and stores in a first register the amount of coded data of each block generated at the first compression factor, and cumulatively counts and stores in a second register the amount of coded data of each block generated at the second compression factor.
Claim 21
Dependent Claim
32 words
An image compression method according to claim 14, wherein said step (c) generates the first and second quantization tables by multiplying a standard quantization table by first and second scale factors, respectively.
Claim 22
Dependent Claim
26 words
An image compression method according to claim 14, wherein said step (c) generates the coded data by executing Huffman coding after the DCT coefficients are quantized.
Claim 23
Dependent Claim
35 words
An image compression method according to claim 15, wherein said step (c) generates the coded data at the first and second compression factors by quantizing the DCT coefficients by using first and second quantization tables.
Claim 24
Dependent Claim
89 words
An image compression method according to claim 16, further comprising the steps of: (d) accumulating the amount of coded data generated at each of the first and second compression factors, for all blocks constituting one frame of the image data; (e) estimating a compression factor suitable for generating coded data of a target data amount, in accordance with the accumulated amounts of coded data generated at the first and second compression factors; and (f) generating coded data of all blocks of the image data at the estimated compression factor.
Claim 25
Dependent Claim
29 words
An image compression method according to claim 20, wherein said step (c) generates the coded data by executing run-length coding and Huffman coding after the DCT coefficients are quantized.
References Cited (Backward Citations)
US5764806A
Cited
US5361220A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-01-10 | 2003-07-12 | 2004-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-01-10 | 2007-07-12 | 2008-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-01-10 | 2011-07-12 | 2012-01-11 | $7700.00 | Window Closed / Lapsed |