| 摘要 |
A recursive filter system 10 for a video image includes a memory 14 to store a first image of stored picture elements S(x,y). Weighted values W(x,y) of luminance and chrominance of a stored picture element S(x,y) are obtained by summing weighted values B(x,y).S(x,y) of luminance and chrominance of the picture element and neighbouring picture elements. A first proportional parameter A(x,y) is generated for the stored picture element based on a modular sum of differences between luminance and chrominance of the stored picture element and of surrounding picture elements. The first proportional parameter A(x,y) is used to generate a weighted picture element M(x,y) from a proportion of the stored picture element S(x,y) and a complementary proportion of the weighted value W(x,y). Picture elements C(x,y) of a next image and a second proportional parameter K are input and a filtered image generated by combining a proportion K of each input picture element of the next image with a complementary proportion 1-K of the weighted stored picture element M(x,y) of the first stored image using the second proportional parameter K. The filtered image is stored for processing a next succeeding image. In embodiments of the invention the second proportional parameter K may be varied pixel to pixel dependent on noise, motion and detail in a region of a picture element being processed.
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