Adaptive image filtering based on a distance transform
AssigneeSharp Laboratories of America, Inc.
InventorsShijun Sun, Shawmin Lei
Life of this patent
Estimating the term…
Abstract
A method for reducing visual artifacts in reconstructed images. One embodiment of the method determines edge energy for each pixel in the image and then compares the edge energy for each pixel to a threshold, producing an edge map. A distance transform is then used to produce a filter map and a filter is applied to pixel in the image, such that the filter applied is dependent upon a filter map value for each pixel. An output value for each pixel is then produced.
Claims24
A method for reducing visual artifacts in reconstructed images, the method comprising:
- a) determining edge energy for each pixel in the image;
- b) comparing the edge energy for each pixel to a threshold, producing an edge map;
- c) using a distance transform to produce a filter map;
- d) applying a filter to each pixel in the image, wherein the filter applied is dependent upon a filter map value for each pixel;
- and
- e) producing an output value for each pixel in the image.
A facsimile machine, comprising:
- a) a receiver operable to receive an input image;
- b) a processor operable to decompress the input image, producing a decompressed image;
- c) a postprocessor operable to
- i) determine edge energy for each pixel in the image;
- ii) compare the edge energy for each pixel to a threshold, producing an edge map;
- iii) use a distance transform to produce a filter map;
- iv) apply a filter to each pixel in the image, wherein the filter applied is dependent upon a filter map value for each pixel;
- and
- v) produce an output value for each pixel in the image;
- and
- d) a print engine operable to print the decompressed and adaptively filtered image.
An article including instructions that, when executed, result in:
- a) determination of edge energy for each pixel in the image;
- b) comparison of the edge energy for each pixel to a threshold, producing an edge map;
- c) use of a distance transform to produce a filter map;
- d) application of a filter to each pixel in the image, wherein the filter applied is dependent upon a filter map value for each pixel;
- and
- e) production of an output value for each pixel in the image.
Dependencies are inferred from the claim text.