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US6882754B2 Expired / Lapsed US ⏱️ 0.0 years remaining

Image signal processor with adaptive noise reduction and an image signal processing method therefor

Assignee: Fujifilm Holdings Corp
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Filing: 2001-06-19
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Granted: 2005-04-19
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Expires: 2021-06-19
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Abstract

Abstract An image signal processing device includes a signal processing circuit for executing signal processing for correction and recording on image data representative of an input image. Also, the signal processing circuit executes noise reduction on the individual image data in accordance with image inputting conditions and/or a pixel level. In the signal processing circuit, a threshold generating circuit generates a threshold by taking account of the image inputting conditions and/or a pixel level. During noise reduction, a noise reducing circuit produces a difference in level between the subject pixel data whose noise is to be detected and the mean value of the subject pixel data and pixel data around the subject pixel. The noise reducing circuit then selects either one of the subject pixel data and mean value in accordance with the difference and threshold.

Inventors

  • 👤 Kenkichi Hayashi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 10:16
CPC Classifications
G; G06; G06T; G06T5/00; G06T5/70; G06T5/20; G06T2207/00; G06T2207/20; G06T2207/20172; G06T2207/20192

Claims Analysis

Total Claims: 28
Claim 1
Independent Claim 150 words
An image signal processing device for executing signal processing on image data representative of an input image, said device comprising: a signal processing circuit for executing signal processing on the image data for correction and recording, and executing noise reduction on individual image data in accordance with at least one of image inputting conditions and a pixel level; said signal processing circuit comprising; a threshold generating circuit for generating a threshold by taking account of at least one of the image inputting conditions and the pixel level; and a noise reducing circuit for producing, during the noise reduction, a difference in level between, subject pixel data whose noise is to be detected and a mean value of said subject pixel data and pixel data around said subject pixel data, and selecting either one of said subject pixel data and said mean value in accordance with said difference and the threshold.
Claim 2
Dependent Claim 150 words
An image signal processing device for executing signal processing on image data representative of an input image, said device comprising: a signal processing circuit for executing signal processing on the image data for correction and recording, and executing noise reduction on individual image data in accordance with at least one of image inputting conditions and a pixel level; said signal processing circuit comprising; a threshold generating circuit for generating a threshold by taking account of at least one of the image inputting conditions and the pixel level; and a noise reducing circuit for producing, during the noise reduction, a difference in level between, subject pixel data whose noise is to be detected and a mean value of said subject pixel data and pixel data around said subject pixel data, and selecting either one of said subject pixel data and said mean value in accordance with said difference and the threshold.
Claim 3
Dependent Claim 40 words
The device in accordance with claim 1 , wherein said threshold generating circuit comprises: a condition collecting circuit for collecting various conditions for determining the threshold; and a calculating circuit for calculating the threshold in accordance with the conditions collected.
Claim 4
Dependent Claim 33 words
The device in accordance with claim 2 , wherein said threshold generating circuit further comprises a threshold correcting circuit for correcting the threshold in accordance with a level of the subject pixel data.
Claim 5
Dependent Claim 39 words
The device in accordance with claim 3 , wherein said condition collecting circuit collects at least one of pickup sensitivity, an exposing condition, a shooting mode, sharpness, a kind of a light source, an operation, and a display magnification.
Claim 6
Dependent Claim 30 words
The device of claim 3 , wherein the threshold is determined for an entire image, and the correcting circuit operates on a pixel by pixel basis to adjust the threshold.
Claim 7
Dependent Claim 116 words
The device in accordance with claim 1 , wherein said noise reducing circuit comprises: a difference calculating circuit for calculating a difference in level between the subject pixel data and the pixel data around said subject pixel data; a mean value calculating circuit for calculating a mean value of the subject pixel data and the pixel data around said subject pixel data; a comparing circuit for comparing the difference and the threshold to thereby determine which of the subject pixel data and the mean value should be used; and a switch for selecting either one of the subject pixel data and the mean value in accordance with a result of comparison output from said comparing circuit.
Claim 8
Dependent Claim 44 words
The device in accordance with claim 6 , wherein said mean value calculating circuit multiplies each pixel data around the subject pixel data by a particular weighting coefficient on the basis of a position of said pixel data to thereby calculate the mean value.
Claim 9
Dependent Claim 66 words
The device according to claim 6 , wherein said difference calculating circuit calculates a selecting difference between the subject pixel data and an average value calculated with 1) the subject pixel data and 2) data around the subject pixel, and wherein the comparing circuit compares the selecting difference and the threshold to determine which of the subject pixel data and the average value should be used.
Claim 10
Dependent Claim 26 words
The device of claim 1 , wherein the noise reducing circuit is operable to alternatively select one of the subject pixel data and the mean value.
Claim 11
Dependent Claim 36 words
The device of claim 1 , wherein the mean value includes a sum of the subject pixel data and n pixel data around said subject pixel, said sum divided by n+1, where n is an integer.
Claim 12
Dependent Claim 43 words
The device of claim 1 , further including an edge detector, wherein the edge detector causes selection of the subject pixel data regardless of the difference between the subject pixel data and mean value when an edge is detected at said subject pixel.
Claim 13
Independent Claim 131 words
A method of processing image data representative of an input image to thereby generate an image, comprising: a first step of collecting image inputting conditions under which the image is input; a second step of calculating a threshold for determining, based on the image inputting conditions, whether or not to use subject pixel data to which noise reduction is to be applied; a third step of calculating a mean value of a level of the subject pixel data and levels of pixel data around said subject pixel; a fourth step of producing a difference between the level of the subject pixel data and the mean value; and a fifth step of comparing the difference and the threshold to thereby select either one of the subject pixel data and the mean value.
Claim 14
Independent Claim 131 words
A method of processing image data representative of an input image to thereby generate an image, comprising: a first step of collecting image inputting conditions under which the image is input; a second step of calculating a threshold for determining, based on the image inputting conditions, whether or not to use subject pixel data to which noise reduction is to be applied; a third step of calculating a mean value of a level of the subject pixel data and levels of pixel data around said subject pixel; a fourth step of producing a difference between the level of the subject pixel data and the mean value; and a fifth step of comparing the difference and the threshold to thereby select either one of the subject pixel data and the mean value.
Claim 15
Dependent Claim 26 words
The method in accordance with claim 12 , further comprising the step of correcting the threshold value calculated in said second step before said fifth step.
Claim 16
Dependent Claim 39 words
The method in accordance with claim 13 , wherein the image inputting conditions comprise at least one of pickup sensitivity, an exposing condition, a shooting mode, sharpness, a king of a light source, an operation, and a display magnification.
Claim 17
Dependent Claim 35 words
The method of claim 13 , wherein the threshold value is determined for an entire image, and the correcting of the threshold value is performed on a pixel by pixel basis to adjust the threshold.
Claim 18
Dependent Claim 39 words
The method in accordance with claim 12 , wherein the image inputting conditions comprise at least one of pickup sensitivity, an exposing condition, a shooting mode, sharpness, a king of a light source, an operation, and a display magnification.
Claim 19
Dependent Claim 46 words
The method in accordance with claim 12 , wherein said third step comprises the step of multiplying each pixel data around the subject pixel data by a particular weighting coefficient on the basis of a position of said pixel data to thereby calculate the mean value.
Claim 20
Dependent Claim 36 words
The method of claim 12 , wherein the mean value includes a sum of the subject pixel data and n pixel data around said subject pixel, said sum divided by n+1, where n is an integer.
Claim 21
Dependent Claim 46 words
The method of claim 12 , further comprising detecting whether an edge occurs at the subject pixel, wherein selection of the subject pixel data occurs regardless of the difference between the subject pixel data and mean value when an edge is detected at said subject pixel.
Claim 22
Dependent Claim 143 words
An image signal processing device for executing signal processing on image data representative of an input image, comprising: a signal processing circuit for executing signal processing on the image data for correction and recording, and executing noise reduction on individual image data in accordance with at least one of image inputting conditions and a pixel level; said signal processing circuit comprising: a threshold generating circuit for generating a threshold by taking account of at least one of the image inputting conditions and the pixel level; and a noise reducing circuit for producing, during the noise reduction, a difference in level between subject pixel data whose noise is to be detected and a mean value of pixel data around the subject pixel data, and selecting either one of the subject pixel data and the mean value in accordance with the difference and the threshold.
Claim 23
Dependent Claim 143 words
An image signal processing device for executing signal processing on image data representative of an input image, comprising: a signal processing circuit for executing signal processing on the image data for correction and recording, and executing noise reduction on individual image data in accordance with at least one of image inputting conditions and a pixel level; said signal processing circuit comprising: a threshold generating circuit for generating a threshold by taking account of at least one of the image inputting conditions and the pixel level; and a noise reducing circuit for producing, during the noise reduction, a difference in level between subject pixel data whose noise is to be detected and a mean value of pixel data around the subject pixel data, and selecting either one of the subject pixel data and the mean value in accordance with the difference and the threshold.
Claim 24
Dependent Claim 40 words
The device in accordance with claim 20 , wherein said threshold generating circuit comprises: a condition collecting circuit for collecting various conditions for determining the threshold; and a calculating circuit for calculating the threshold in accordance with the conditions collected.
Claim 25
Dependent Claim 33 words
The device in accordance with claim 21 , wherein said threshold generating circuit further comprises a threshold correcting circuit for correcting the threshold in accordance with a level of the subject pixel data.
Claim 26
Dependent Claim 39 words
The device in accordance with claim 22 , wherein said condition collecting circuit collects at least one of pickup sensitivity, an exposing condition, a shooting mode, sharpness, a kind of a light source, an operation, and a display magnification.
Claim 27
Dependent Claim 111 words
The device in accordance with claim 20 , wherein said noise reducing circuit comprises: a difference calculating circuit for calculating a difference in level between the subject pixel data and the pixel data around the subject pixel data; a mean value calculating circuit for calculating a mean value of the pixel data around the subject pixel data; a comparing circuit for comparing the difference and the threshold to thereby determine which of the subject pixel data and the mean value should be used; and a switch for selecting either one of the subject pixel data and the mean value in accordance with a result of comparison output from said comparing circuit.
Claim 28
Dependent Claim 44 words
The device in accordance with claim 24 , wherein said mean value calculating circuit multiplies each pixel data around the subject pixel data by a particular weighting coefficient on the basis of a position of the pixel data to thereby calculate the mean value.

References Cited (Backward Citations)

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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) 2008-04-18 2008-10-18 2009-04-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2012-04-18 2012-10-18 2013-04-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2016-04-18 2016-10-18 2017-04-19 $7700.00 Window Closed / Lapsed

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