Anisotropic denoising method
First Claim
1. A machine-implemented method comprising:
- determining an initial denoised pixel value for a color component of a particular pixel based at least in part upon a value of the color component of the particular pixel and values of the color component of a set of other pixels;
for at least a first pixel in the set of other pixels, determining whether the first pixel is to be used in denoising the particular pixel;
in response to determining that the first pixel is to be used to denoise the particular pixel, determining a weight value to be assigned to the first pixel;
determining the initial denoised pixel value for the particular pixel based at least in part upon the weight value and a value of the color component for the first pixel;
determining a type of image environment in which the particular pixel is situated, the type of image environment being one of a set comprising (a) edge/line and (b) detail;
based at least in part upon the type of image environment, determining an adjusted denoising power value for the color component of the particular pixel; and
based at least in part upon the initial denoised pixel value and the adjusted denoising power value, determining a final denoised pixel value for the color component of the particular pixel.
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Accused Products
Abstract
In accordance with an embodiment of the invention, an anisotropic denoising method is provided that removes sensor noise from a digital image while retaining edges, lines, and details in the image. In one embodiment, the method removes noise from a pixel of interest based on the detected type of image environment in which the pixel is situated. If the pixel is situated in an edge/line image environment, then denoising of the pixel is increased such that relatively stronger denoising of the pixel occurs along the edge or line feature. If the pixel is situated in a detail image environment, then denoising of the pixel is decreased such that relatively less denoising of the pixel occurs so as to preserve the details in the image. In one embodiment, detection of the type of image environment is accomplished by performing simple arithmetic operations using only pixels in a 9 pixel by 9 pixel matrix of pixels in which the pixel of interest is situated. As a result, improved image environment sensitive noise reduction is achieved that requires a relatively low gate count in hardware implementations.
22 Citations
27 Claims
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1. A machine-implemented method comprising:
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determining an initial denoised pixel value for a color component of a particular pixel based at least in part upon a value of the color component of the particular pixel and values of the color component of a set of other pixels; for at least a first pixel in the set of other pixels, determining whether the first pixel is to be used in denoising the particular pixel; in response to determining that the first pixel is to be used to denoise the particular pixel, determining a weight value to be assigned to the first pixel; determining the initial denoised pixel value for the particular pixel based at least in part upon the weight value and a value of the color component for the first pixel; determining a type of image environment in which the particular pixel is situated, the type of image environment being one of a set comprising (a) edge/line and (b) detail; based at least in part upon the type of image environment, determining an adjusted denoising power value for the color component of the particular pixel; and based at least in part upon the initial denoised pixel value and the adjusted denoising power value, determining a final denoised pixel value for the color component of the particular pixel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A device comprising one or more logic elements configured for:
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determining an initial denoised pixel value for a color component of a particular pixel based at least in part upon a value of the color component of the particular pixel and values of the color component of a set of other pixels; for at least a first pixel in the set of other pixels, determining whether the first pixel is to be used in denoising the particular pixel; in response to determining that the first pixel is to be used to denoise the particular pixel, determining a weight value to be assigned to the first pixel; determining the initial denoised pixel value for the particular pixel based at least in part upon the weight value and a value of the color component for the first pixel; determining a type of image environment in which the particular pixel is situated, the type of image environment being one of a set comprising (a) edge/line and (b) detail; based at least in part upon the type of image environment, determining an adjusted denoising power value for the color component of the particular pixel; and based at least in part upon the initial denoised pixel value and the adjusted denoising power value, determining a final denoised pixel value for the color component of the particular pixel. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification