US6459816B2
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Image processing system for compressing image data including binary image data and continuous tone image data by a sub-band transform method with a high-compression rate
Assignee: Ricoh Co Ltd
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Filing: 1998-05-07
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Granted: 2002-10-01
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Expires: 2018-05-07
Abstract
Abstract An image processing system which compresses an image including both a binary image and a continuous tone image by a sub-band transform method with a high compression rate. A 2×2 pixel matrix block is extracted from image data. A transform factor having a plurality of frequency components is obtained from the 2×2 pixel matrix block data. The transform factor is quantized by a fixed-length quantizing method by deleting a predetermined number of lower order bits of each of the frequency components.
Inventors
- 👤 Nekka Matsuura
- 👤 Yukiko Yamazaki
- 👤 Takahiro Yagishita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:44
CPC Classifications
G; G06; G06T; G06T9/00; G06T9/005; G06T9/007
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
132 words
An image processing system comprising: a buffer unit extracting n×m pixel matrix block data from image data, where n and m are integers; a sub-band transform unit transforming the n×m pixel matrix block data by a sub-band transform method so as to obtain a transform factor having a plurality of frequency components; and a quantizing unit quantizing the transform factor by a fixed-length quantizing method by deleting a predetermined number of lower order bits of each of the frequency components, wherein the frequency components comprise low frequency component LL and high frequency components HL, LH and HH, and the quantizing unit deletes two lower order bits from the LL frequency component, four lower order bits from the HL and LH frequency components, and six lower order bits from the HH frequency components.
Claim 2
Dependent Claim
132 words
An image processing system comprising: a buffer unit extracting n×m pixel matrix block data from image data, where n and m are integers; a sub-band transform unit transforming the n×m pixel matrix block data by a sub-band transform method so as to obtain a transform factor having a plurality of frequency components; and a quantizing unit quantizing the transform factor by a fixed-length quantizing method by deleting a predetermined number of lower order bits of each of the frequency components, wherein the frequency components comprise low frequency component LL and high frequency components HL, LH and HH, and the quantizing unit deletes two lower order bits from the LL frequency component, four lower order bits from the HL and LH frequency components, and six lower order bits from the HH frequency components.
Claim 3
Dependent Claim
129 words
An image processing method comprising the steps of: extracting n×m pixel matrix block data from image data, where n and m are integers; transforming the n×m pixel matrix block data by a sub-band transform method so as to obtain a transform factor having a plurality of frequency components; and quantizing the transform factor by a fixed-length quantizing method by deleting a predetermined number of lower order bits of each of the frequency components, wherein the frequency components comprise low frequency component LL and high frequency components HL, LH and HH, and the quantizing step further comprises: deleting two lower order bits from the LL frequency component; deleting four lower order bits from the HL and LH frequency components; and deleting six lower order bits from the HH frequency component.
Claim 4
Dependent Claim
129 words
An image processing method comprising the steps of: extracting n×m pixel matrix block data from image data, where n and m are integers; transforming the n×m pixel matrix block data by a sub-band transform method so as to obtain a transform factor having a plurality of frequency components; and quantizing the transform factor by a fixed-length quantizing method by deleting a predetermined number of lower order bits of each of the frequency components, wherein the frequency components comprise low frequency component LL and high frequency components HL, LH and HH, and the quantizing step further comprises: deleting two lower order bits from the LL frequency component; deleting four lower order bits from the HL and LH frequency components; and deleting six lower order bits from the HH frequency component.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-09-30 | 2006-04-01 | 2006-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-09-30 | 2010-04-01 | 2010-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-09-30 | 2014-04-01 | 2014-10-01 | $7700.00 | Window Closed / Lapsed |