US5295077A
Expired / Lapsed
US
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Digital electronic still camera
Assignee: Ricoh Co Ltd
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Filing: 1992-01-23
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Granted: 1994-03-15
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Expires: 2012-01-23
Abstract
Abstract A digital electronic still camera has an image pickup device to pick up an image to be photographed. The picked-up image data is compressed by a data compressing unit using the two-dimensional discrete cosine transformation (DCT), the optimum quantization table, and the Huffman coding. The optimum quantization table is selected by comparing a characteristic parameter of the image data with preliminarily obtained values for respective image kinds. The two-dimensional DCT provides transformation coefficients of image, which are linearly quantized with reference to the optimum quantization table. The quantized data is coded by the Huffman coding method to have a minimum length. The coded data is sent to a recording device, which records the coded data in a recording medium such as a memory card. Fuzzy control theory may be applied to determine whether the image attributes to a document, a portrait, or a landscape. The image attribute may also manually be set, for example, on an input device.
Inventors
- 👤 Hiroki Fukuoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:14
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/10; H04N19/134; H04N19/136; H04N19/14; H04N19/102; H04N19/124; H04N19/126; Y; Y10; Y10S; Y10S706/00; Y10S706/90
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
160 words
A digital electronic still camera, comprising: image pickup means for picking up an image of a field to be photographed; block-dividing means for dividing the image into a plurality of blocks which are respectively made up of a plurality of pixels; transforming means for executing an adaptive discrete cosine transformation of each block of the image to generate a corresponding block of image data; quantizing means for quantizing the image data of each block with reference to a quantization table selected as an optimum one from a plurality of quantization tables having different quantization step sizes; image attributable judging means for judging an image attribute based on a spectrum distribution of the image data selected as membership functions of fuzzy decision; quantization table setting means for selecting a quantization table as the optimum one based on the image attribute obtained; coding means for coding the image data quantized; and recording means for recording the coded image data into a memory.
Claim 2
Dependent Claim
160 words
A digital electronic still camera, comprising: image pickup means for picking up an image of a field to be photographed; block-dividing means for dividing the image into a plurality of blocks which are respectively made up of a plurality of pixels; transforming means for executing an adaptive discrete cosine transformation of each block of the image to generate a corresponding block of image data; quantizing means for quantizing the image data of each block with reference to a quantization table selected as an optimum one from a plurality of quantization tables having different quantization step sizes; image attributable judging means for judging an image attribute based on a spectrum distribution of the image data selected as membership functions of fuzzy decision; quantization table setting means for selecting a quantization table as the optimum one based on the image attribute obtained; coding means for coding the image data quantized; and recording means for recording the coded image data into a memory.
Claim 3
Dependent Claim
26 words
A digital electronic still camera according to claim 1, wherein the plurality of quantization tables are quantization tables for a document, a portrait and a landscape.
Claim 4
Dependent Claim
37 words
A digital electronic still camera according to claim 2, wherein the optimum quantization table is constructed by selecting a quantization table based on the image attribute obtained and multiplying the selected quantization table by a scaling factor.
Claim 5
Dependent Claim
24 words
A digital electronic still camera according to claim 1, wherein the plurality of quantization tables are quantization tables for a document and a nature.
Claim 6
Dependent Claim
37 words
A digital electronic still camera according to claim 4, wherein the optimum quantization table is constructed by selecting a quantization table based on the image attribute obtained and multiplying the selected quantization table by a scaling factor.
Claim 7
Dependent Claim
32 words
A digital electronic still camera according to claim 1, wherein the plurality of blocks are respectively made up of N×N pixels, where N is an integer greater than or equal to two.
Claim 8
Dependent Claim
163 words
A digital electronic still camera, comprising: image pickup means for picking up an image of a field to be photographed; block-dividing means for dividing the image into a plurality of blocks which are respectively made up of a plurality of pixels; transforming means for executing an orthogonal transformation of each block of the image to generate a corresponding block of image data; quantizing means for quantizing the image data of each block with reference to a quantization table selected as an optimum one from a plurality of quantization tables including at least a quantization table for a document; image attribute judging means for judging an image attribute based on a spectrum distribution of the image data selected as membership functions as fuzzy decision; quantization table setting means for selecting a quantization table as the optimum one based on the image attribute obtained; coding means for coding the image data quantized; and recording means for recording the coded image data into a memory card.
Claim 9
Dependent Claim
163 words
A digital electronic still camera, comprising: image pickup means for picking up an image of a field to be photographed; block-dividing means for dividing the image into a plurality of blocks which are respectively made up of a plurality of pixels; transforming means for executing an orthogonal transformation of each block of the image to generate a corresponding block of image data; quantizing means for quantizing the image data of each block with reference to a quantization table selected as an optimum one from a plurality of quantization tables including at least a quantization table for a document; image attribute judging means for judging an image attribute based on a spectrum distribution of the image data selected as membership functions as fuzzy decision; quantization table setting means for selecting a quantization table as the optimum one based on the image attribute obtained; coding means for coding the image data quantized; and recording means for recording the coded image data into a memory card.
Claim 10
Dependent Claim
19 words
A digital electronic still camera according to claim 7, wherein the orthogonal transformation is an adaptive discrete cosine transformation.
Claim 11
Dependent Claim
32 words
A digital electronic still camera according to claim 7, wherein the plurality of blocks are respectively made up of N×N pixels, where N is an integer greater than or equal to two.
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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) | 1997-03-14 | 1997-09-13 | 1998-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-14 | 2001-09-13 | 2002-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-14 | 2005-09-13 | 2006-03-15 | $7700.00 | Window Closed / Lapsed |