Methods for suppressing structured noise in a digital image
AssigneeFoveon, Inc.
InventorRastislav Lukac
Life of this patent
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Abstract
A method for suppressing structured noise in a digital image includes creating a smoothed version of the original image. Monotonic and slowly-varying image regions are detected by analyzing a residual image which is the function of the original image and its smoothed version. A local window is defined in each pixel location identified in the thresholding process as the location with structured noise and samples inside the window are randomly permuted to randomize the noise structures. A noise-filtered version of the original residual image is generated. The noise-filtered residual and the smoothed version of the original image are combined to produce a final image.
Claims32
A method for suppressing structured noise in an original image, comprising:
- generating a smoothed version of the original image;
- generating a residual image from the original image and the smoothed version of the original image;
- detecting monotonic and slowly-varying image regions by analyzing the residual image;
- defining a local window in each pixel location identified in a thresholding process as being in the monotonic and slowly-varying image regions;
- randomly permuting residual image samples inside the window to randomize the noise structures, thus generating a noise-filtered version of the residual image;
- and
- combining the smoothed image and the noise-filtered version of the residual image to produce a final image.
A method for suppressing structured noise in a digital image, comprising:
- creating a smoothed version of the original image;
- detecting monotonic and slowly-varying image regions by analyzing a residual image which is the function of the original image and its smoothed version;
- defining a first one-dimensional window;
- in each pixel location inside the region identified in a thresholding process as being in the monotonic and slowly-varying image regions with structured noise, randomly permuting samples inside the first one-dimensional window to randomize the noise structures;
- defining a second one-dimensional window;
- in each pixel location inside the region identified in the thresholding process as being in the monotonic and slowly-varying image regions with structured noise, randomly permuting samples inside the second one-dimensional window to randomize the noise structures;
- combining the noise-filtered (randomized) residual and the smoothed version of the original image to produce a final image.
A method for suppressing structured noise in a digital color image, comprising:
- generating a smoothed version of the image;
- generating a residual image from the original image and its smoothed version;
- generating a grayscale residual image by averaging the color components of the residual image in each pixel location to create a grayscale residual image;
- detecting monotonic and slowly-varying image regions by analyzing the residual image;
- defining a local window in each pixel location identified in a thresholding process as being in a monotonic and slowly-varying image region;
- randomly permuting residual image samples inside the window to randomize the noise structures;
- generating a noise-filtered version of the grayscale residual image;
- combining the noise-filtered version of the grayscale residual image and each color channel of the smoothed image to produce a final color image.
A method for suppressing structured noise in a digital color image, comprising:
- generating a grayscale version of the original color image;
- generating a smoothed version of the original color image;
- generating a grayscale version of the smoothed color image;
- generating a residual image from the grayscale version of the original image and grayscale version of the smoothed color image;
- detecting monotonic and slowly-varying image regions by analyzing the residual image;
- defining a local window in each pixel location identified in a thresholding process as being in a monotonic and slowly-varying image regions;
- randomly permuting residual image samples inside the window to randomize the noise structures;
- generating a noise-filtered version of the residual image;
- combining the noise-filtered version of the residual image and each color channel of the smoothed image to produce a final color image.
Dependencies are inferred from the claim text.