EP0705025A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and apparatus for reducing quantization artifacts in a hierarchical image storage and retrieval system
Assignee: Eastman Kodak Co
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Filing: 1995-09-25
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Granted: —
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Expires: 2015-09-25
Abstract
Abstract The system and method reduces the quantization artifacts in the addition and removal of a digital watermark to and from a selected resolution image of a hierarchical image storage system where the watermark removal record is placed in a higher resolution image component. For those applications where preserving the image quality of a higher resolution image component is more critical than preserving the image quality of a lower resolution image component, the low-resolution image is modified according to the teachings of the present invention to minimize and in many cases eliminate the quantization artifacts at the higher resolution component.
Inventors
- 👤 Majid c/o Eastman Kodak Company Rabbani
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 19:39
CPC Classifications
G; G06; G06T; G06T1/00; G06T1/0021; G06T1/0028; H; H04; H04N; H04N1/00; H04N1/32; H04N1/32101; H04N1/32144; H04N1/32149; H04N1/32203; H04N1/32251; H04N1/32267; H04N1/40; H04N1/40068; H04N21/00; H04N21/20; H04N21/23; H04N21/238; H04N21/2389; H04N21/23892; H04N21/80; H04N21/83; H04N21/835; H04N21/8358; H04N2201/00; H04N2201/32; H04N2201/3201; H04N2201/3225; H04N2201/3233; H04N2201/3273; H04N2201/3274; H04N2201/328
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
140 words
A method for reducing quantization artifacts in a hierarchical image system of the type that decomposes a high resolution image into low resolution image components, including low resolution image pixel values, and residual image pixel values comprising the steps of: a) determining the difference values between the pixel values in the low resolution image and the corresponding pixel values in the higher resolution image; b) comparing each of the difference values against quantizer conversion values to determine if an error would exist for an executed conversion; c) adjusting the image pixel values within the low resolution image component if an error would exist, to a value that eliminates the error to form an adjusted low resolution image; and d) using the unadjusted image pixel values as part of the adjusted low resolution image component if an error does not exist.
Claim 2
Dependent Claim
137 words
A method according to Claim 1 further comprising : e) forming a predicted higher resolution image by interpolating the pixel values of the adjusted low resolution image components of steps c) and d); f) determining the difference values between the interpolated pixel values in the predicted higher resolution image and the corresponding pixel values in the higher resolution image; g) comparing each of the difference values against quantizer conversion values to determine if an error would exist for an executed conversion; h) adjusting further the image pixel values within the adjusted low resolution image component if an error would exist, to a value that eliminates the error to form an adjusted low resolution image; and i) using the unadjusted image pixel value as part of the adjusted low resolution image component if an error does not exist.
Claim 3
Dependent Claim
40 words
A method for according to Claim 2, wherein a step of applying watermark pixel values to pixel positions within the low resolution image is performed before step a) and said modified low resolution image is used as low resolution image.
Claim 4
Dependent Claim
48 words
A method according to Claim 3, wherein the predicted higher resolution image of step e) is formed by sequentially interpolating the pixel values of a first block of low resolution image pixel values and steps f) through i) are repeated for each pixel in the higher resolution image.
Claim 5
Dependent Claim
25 words
A storage device having stored thereon the adjusted low resolution image components and the residual image pixel values of any of Claims 1 to 4.
Claim 6
Dependent Claim
138 words
Apparatus for reducing quantization artifacts in a hierarchical image system of the type that decomposes a high resolution image into low resolution components, including low resolution image pixel values, and residual image pixel values, comprising: means for determining the difference values between the pixel values in the low resolution image and the corresponding pixel values in the higher resolution image; means for comparing each of the difference values against quantizer conversion values to determine if an error would exist for an executed conversion; and means for adjusting the image pixel values within the low resolution image component if an error would exist, to a value that eliminates the error to form an adjusted low resolution image component and using the image pixel value as part of the adjusted low resolution image component if an error does not exist.
Claim 7
Dependent Claim
137 words
Apparatus according to Claim 6 further comprising : means for forming a predicted higher resolution image by interpolating the pixel values of the adjusted low resolution image component; means for determining the difference values between the interpolated pixel values in the predicted higher resolution image and the corresponding pixel values in the higher resolution image; means for comparing each of the difference values against quantizer conversion values to determine if an error would exist for an executed conversion; means for adjusting the image pixel values within the adjusted low resolution image component if an error would exist, to a value that eliminates the error to form a twice adjusted low resolution image component; and means for using the image pixel value as part of the twice adjusted low resolution image component if an error does not exist.
Claim 8
Dependent Claim
27 words
Apparatus according to Claim 7, further comprising: means for applying pixel values to pixel positions within the low resolution image to form a low resolution image component.
References Cited (Backward Citations)
US4969204A
Cited
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