Patent US6646246B1 successfully refreshed from Google Patents.
US6646246B1
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US
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Method and system of noise removal for a sparsely sampled extended dynamic range image sensing device
Assignee: Apple Inc
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Filing: 2000-11-21
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Granted: 2003-11-11
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Expires: 2020-11-21
Abstract
Abstract A method of removing noise from a sparsely sampled extended dynamic range image produced by a sparsely sampled extended dynamic range image sensing device having fast photosites with a predetermined response to a light exposure for producing fast pixel values and slow photosites with a slower response to the same light exposure for producing slow pixel values, includes the steps of: providing a sparsely sampled extended dynamic range digital image having fast and slow pixel values; using a noise filter method to remove noise from the sparsely sampled extended dynamic range digital image by using only slow pixel values to generate slow noise reduced pixel values and using only fast pixel values to generate fast noise reduced pixel values; and combining the slow noise reduced pixel values and the fast noise reduced pixel values to generate a noise reduced sparsely sampled digital image.
Inventors
- 👤 Edward B. Gindele
- 👤 Andrew C. Gallagher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:07
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/70; H04N23/80; H04N23/84; H04N23/843; H04N25/00; H04N25/60; H04N25/10; H04N25/11; H04N25/13; H04N25/134
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
146 words
A method of removing noise from a sparsely sampled extended dynamic range image produced by a sparsely sampled extended dynamic range image sensing device having fast photosites with a predetermined response to a light exposure for producing fast pixel values and slow photosites with a slower response to the same light exposure for producing slow pixel values, comprising the steps of: a) providing a sparsely sampled extended dynamic range digital image having fast and slow pixel values; b) using a noise filter method to remove noise from the sparsely sampled extended dynamic range digital image by using only slow pixel values to generate slow noise reduced pixel values and using only fast pixel values to generate fast noise reduced pixel values; and c) combining the slow noise reduced pixel values and the fast noise reduced pixel values to generate a noise reduced sparsely sampled digital image.
Claim 2
Independent Claim
146 words
A method of removing noise from a sparsely sampled extended dynamic range image produced by a sparsely sampled extended dynamic range image sensing device having fast photosites with a predetermined response to a light exposure for producing fast pixel values and slow photosites with a slower response to the same light exposure for producing slow pixel values, comprising the steps of: a) providing a sparsely sampled extended dynamic range digital image having fast and slow pixel values; b) using a noise filter method to remove noise from the sparsely sampled extended dynamic range digital image by using only slow pixel values to generate slow noise reduced pixel values and using only fast pixel values to generate fast noise reduced pixel values; and c) combining the slow noise reduced pixel values and the fast noise reduced pixel values to generate a noise reduced sparsely sampled digital image.
Claim 3
Dependent Claim
84 words
The method of claim 1 wherein the noise filter method includes the steps of: identifying a pixel of interest and a local neighborhood of pixels located about the pixel of interest; calculating a difference pixel value for pixels in the local neighborhood of pixels based on the absolute difference between the value of the pixel of interest and the individual values of pixels included in the local neighborhood of pixels; and using the absolute difference pixel values to calculate a noise reduced pixel value.
Claim 4
Dependent Claim
66 words
The method of claim 2 , wherein the step of using the absolute difference pixel values, further includes the steps of: comparing the absolute difference pixel values to a threshold value; and using only the values of pixels included in the local neighborhood of pixels for which the corresponding absolute difference pixel values are less than the threshold value to calculate the noise reduced pixel value.
Claim 5
Dependent Claim
53 words
The method of claim 3 , wherein the threshold value is determined by: providing a table of two or more noise characteristic values; using the values of pixels in the local neighborhood of pixels to select one of the noise characteristic values; and using the selected noise characteristic value as the threshold value.
Claim 6
Dependent Claim
25 words
The method of claim 4 , wherein different tables of noise characteristic values are provided for the slow pixel values and the fast pixel values.
Claim 7
Dependent Claim
64 words
The method of claim 5 , wherein the sparsely sampled extended dynamic range digital image includes red, green, and blue slow pixel values and red, green, and blue fast pixel values and wherein different tables of noise characteristic values are provided respectively for the red slow, green slow and blue slow pixel values and the red fast, green fast and blue fast pixel values.
Claim 8
Dependent Claim
14 words
The method of claim 1 wherein the noise filter method employs a median filter.
Claim 9
Dependent Claim
33 words
The method of claim 1 , further comprising the step of: d) expanding the dynamic range of the noise reduced fast and slow pixel values in the noise reduced sparsely sampled digital image.
Claim 10
Dependent Claim
54 words
The method of claim 8 , wherein the sparsely sampled extended dynamic range digital image includes red, green and blue slow pixel values and red, green and blue fast pixel values, and further including the step of: using an interpolation spatial filter to generate missing pixel values to produce a noise reduced digital image.
Claim 11
Independent Claim
145 words
A system for removing noise from a sparsely sampled extended dynamic range image produced by a sparsely sampled extended dynamic range image sensing device having fast photosites with a predetermined response to a light exposure for producing fast pixel values and slow photosites with a slower response to the same light exposure for producing slow pixel values, comprising: a) means for providing a sparsely sampled extended dynamic range digital image having fast and slow pixel values; b) a noise filter for removing noise from the sparsely sampled extended dynamic range digital image by using only slow pixel values to generate slow noise reduced pixel values and using only fast pixel values to generate fast noise reduced pixel values; and c) means for combining the slow noise reduced pixel values and the fast noise reduced pixel values to generate a noise reduced sparsely sampled digital image.
Claim 12
Independent Claim
145 words
A system for removing noise from a sparsely sampled extended dynamic range image produced by a sparsely sampled extended dynamic range image sensing device having fast photosites with a predetermined response to a light exposure for producing fast pixel values and slow photosites with a slower response to the same light exposure for producing slow pixel values, comprising: a) means for providing a sparsely sampled extended dynamic range digital image having fast and slow pixel values; b) a noise filter for removing noise from the sparsely sampled extended dynamic range digital image by using only slow pixel values to generate slow noise reduced pixel values and using only fast pixel values to generate fast noise reduced pixel values; and c) means for combining the slow noise reduced pixel values and the fast noise reduced pixel values to generate a noise reduced sparsely sampled digital image.
Claim 13
Dependent Claim
86 words
The system of claim 10 wherein the noise filter includes: means for identifying a pixel of interest and a local neighborhood of pixels located about the pixel of interest; means for calculating a difference pixel value for pixels in the local neighborhood of pixels based on the absolute difference between the value of the pixel of interest and the individual values of pixels included in the local neighborhood of pixels; and means for using the absolute difference pixel values to calculate a noise reduced pixel value.
Claim 14
Dependent Claim
67 words
The system of claim 11 , wherein the means for using the absolute difference pixel values, further includes: means for comparing the absolute difference pixel values to a threshold value; and means for using only the values of pixels included in the local neighborhood of pixels for which the corresponding absolute difference pixel values are less than the threshold value to calculate the noise reduced pixel value.
Claim 15
Dependent Claim
58 words
The system of claim 12 , further comprising means for determining the threshold value comprising: a table of two or more noise characteristic values; means for using the values of pixels in the local neighborhood of pixels to select one of the noise characteristic values; and means for using the selected noise characteristic value as the threshold value.
Claim 16
Dependent Claim
23 words
The system of claim 13 , including different tables of noise characteristic values for the slow pixel values and the fast pixel values.
Claim 17
Dependent Claim
62 words
The system of claim 14 , wherein the sparsely sampled extended dynamic range digital image includes red, green and blue slow pixel values and red, green and blue fast pixel values and including different tables of noise characteristic values respectively for the red slow, green slow and blue slow pixel values and the red fast, green fast and blue fast pixel values.
Claim 18
Dependent Claim
13 words
The system of claim 10 wherein the noise filter includes a median filter.
Claim 19
Dependent Claim
32 words
The system of claim 10 , further comprising: d) means for expanding the dynamic range of the noise reduced fast and slow pixel values in the noise reduced sparsely sampled digital image.
Claim 20
Dependent Claim
50 words
The system of claim 17 , wherein the sparsely sampled extended dynamic range digital image includes red, green and blue slow pixel values and red, green and blue fast pixel values, and further including: an interpolation spatial filter for generating missing pixel values to produce a noise reduced digital image.
Claim 21
Dependent Claim
12 words
A computer program product for performing the method of claim 1 .
Claim 22
Dependent Claim
11 words
A digital image produced by the method of claim 1 .
Claim 23
Dependent Claim
15 words
The method of claim 1 , wherein the method is performed in a digital camera.
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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) | 2006-11-10 | 2007-05-12 | 2007-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-11-10 | 2011-05-12 | 2011-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-11-10 | 2015-05-12 | 2015-11-11 | $7700.00 | Window Closed / Lapsed |