Image processing device, image processing method, and integrated circuit
First Claim
1. An image processing device for correcting pixel values of an image to reduce noise in the image, the image processing device comprising:
- a determination unit configured to;
specify, on a normal distribution representing a noise model of the image, a reference range having a value of a target pixel as a median;
compute, with respect to a local region that is an image region containing the target pixel, the number of pixels having a value falling within a first sub-range of the reference range and the number of pixels having a value falling within a second sub-range of the reference range, the first sub-range corresponding to larger values than the median and the second sub-range corresponding to smaller values than the median;
correct one of the first sub-range and the second sub-range so that one of the sub-ranges in which a fewer number of pixels are distributed than in the other sub-range is narrower relative to the other sub-range; and
determine a selection range that is composed of the one of the first sub-range and the second sub-range as corrected and the other one of the first sub-range and the second sub-range as is; and
a generating unit configured to generate a corrected value for the target pixel by correcting values of pixels contained in a target region to reduce noise, the target region being an image region subjected to noise reduction and at least containing the local region, and the value correction involving use of values falling within the selection range from among the values of the respective pixels contained in the target region.
3 Assignments
0 Petitions
Accused Products
Abstract
Provided is an image processing device capable of performing appropriate noise reduction without causing blurring of edges and details of the image. The image processing device: specifies, on a normal distribution representing a noise model of the image, a reference range having a value of a target pixel as a median; computes, with respect to a local region that is an image region containing the target pixel, the number of pixels having a value falling within a first sub-range of the reference range and the number of pixels having a value falling within a second sub-range of the reference range, the first sub-range corresponding to larger values than the median and the second sub-range corresponding to smaller values than the median; corrects one of the first sub-range and the second sub-range so that one of the sub-ranges in which a fewer number of pixels are distributed than in the other sub-range is narrower relative to the other sub-range; determines a selection range that is composed of the one of the first sub-range and the second sub-range as corrected and the other one of the first sub-range and the second sub-range as is; and performs noise reduction on an image region subjected to noise reduction and at least containing the local region by using values falling within the selection range from among the values of the respective pixels contained in the target region.
16 Citations
10 Claims
-
1. An image processing device for correcting pixel values of an image to reduce noise in the image, the image processing device comprising:
-
a determination unit configured to; specify, on a normal distribution representing a noise model of the image, a reference range having a value of a target pixel as a median; compute, with respect to a local region that is an image region containing the target pixel, the number of pixels having a value falling within a first sub-range of the reference range and the number of pixels having a value falling within a second sub-range of the reference range, the first sub-range corresponding to larger values than the median and the second sub-range corresponding to smaller values than the median; correct one of the first sub-range and the second sub-range so that one of the sub-ranges in which a fewer number of pixels are distributed than in the other sub-range is narrower relative to the other sub-range; and determine a selection range that is composed of the one of the first sub-range and the second sub-range as corrected and the other one of the first sub-range and the second sub-range as is; and a generating unit configured to generate a corrected value for the target pixel by correcting values of pixels contained in a target region to reduce noise, the target region being an image region subjected to noise reduction and at least containing the local region, and the value correction involving use of values falling within the selection range from among the values of the respective pixels contained in the target region. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. An image processing method for an image processing device to correct pixel values of an image to reduce noise, the image processing method comprising:
-
a determining step of; specifying, on a normal distribution representing a noise model of the image, a reference range having a value of a target pixel as a median; computing, with respect to a local region that is an image region containing the target pixel, the number of pixels having a value falling within a first sub-range of the reference range and the number of pixels having a value falling within a second sub-range of the reference range, the first sub-range corresponding to larger values than the median and the second sub-range corresponding to smaller values than the median; correcting one of the first sub-range and the second sub-range so that one of the sub-ranges in which a fewer number of pixels are distributed than in the other sub-range is narrower relative to the other sub-range; and determining a selection range that is composed of the one of the first sub-range and the second sub-range as corrected and the other one of the first sub-range and the second sub-range as is; and a generating step of generating a corrected value for the target pixel by correcting values of pixels contained in a target region to reduce noise, the target region being an image region subjected to noise reduction and at least containing the local region, and the value correction involving use of values falling within the selection range from among the values of the respective pixels contained in the target region.
-
-
9. An integrated circuit to be used in an image processing device that corrects pixel values of an image to reduce noise, the integrated circuit comprising:
-
a determination unit configured to; specify, on a normal distribution representing a noise model of the image, a reference range having a value of a target pixel as a median; compute, with respect to a local region that is an image region containing the target pixel, the number of pixels having a value falling within a first sub-range of the reference range and the number of pixels having a value falling within a second sub-range of the reference range, the first sub-range corresponding to larger values than the median and the second sub-range corresponding to smaller values than the median; correct one of the first sub-range and the second sub-range so that one of the sub-ranges in which a fewer number of pixels are distributed than in the other sub-range is narrower relative to the other sub-range; and determine a selection range that is composed of the one of the first sub-range and the second sub-range as corrected and the other one of the first sub-range and the second sub-range as is; and a generating unit configured to generate a corrected value for the target pixel by correcting values of pixels contained in a target region to reduce noise, the target region being an image region subjected to noise reduction and at least containing the local region, and the value correction involving use of values falling within the selection range from among the values of the respective pixels contained in the target region.
-
-
10. An image processing device for correcting pixel values of an image to reduce noise, the image processing device comprising:
-
a first noise reduction unit configured to; specify, on a normal distribution representing a noise model of the image, a first reference range having a value of a target pixel as a median; and generate noise reduced pixel values by performing noise reduction processing on an initial target region that is an image region subjected to noise reduction and containing the target pixel, the noise reduction of the initial target region involving use of values falling within the first reference range from among values of respective pixels contained in the target region; and a second noise reduction unit configured to; specify, on the normal distribution representing the noise model of the image, a second reference range narrower than the first reference range and having, as a median, the noise reduced pixel value generated for the target pixel; and generate noise reduced pixel values by performing noise reduction processing on an enlarged target region that is an image region subjected to noise reduction and at least containing the initial target region, the noise reduction of the enlarged target region involving use of values falling within the second reference range from among values of respective pixels contained in the target region.
-
Specification