| 摘要 |
A method of processing a video image 500 to determine an edge strength 502 in a region associated with each image pixel to be processed, wherein for large edge strengths, the pixel is filtered by an edge-preserving filter 504, which may be an epsilon filter, and for small edge strengths, the edge-preserving filter is replaced by a smoothing filter 505,506. For very large edge strengths 502, which may be within 20% of a maximum value, no filter may be applied. A directional filter may also be applied when the edge-preserving filter 504 is applied. The smoothing filter may comprise an image blurring filter 505 followed by an image sharpening filter 506. A weighted combination of edge-preserving filter 504 and smoothing filter 505,506 may be applied in a blend mode 507 according to the size of the edge strength 502. The edge strength 502 may be determined as a function of variations in pixel values in a plurality of pixel blocks, which may be in a single pixel row, in the neighbourhood of the pixel to be processed. Epsilon edge-preserving filtering performs well at reducing mosquito noise near edges, but it tends to create jaggy edges, especially on diagonal edges. This image processing method is used to improve the quality of digital TV and video by smoothing the jagged diagonal edges. |
