Deblocking filtering

摘要

Blocking artifacts at a block boundary between a block and a neighboring block in a video frame are reduced by calculating an offset based on pixel values of pixels in a line of pixels in the block and based on pixel values of pixels in a corresponding line of pixels in the neighboring block. The offset is added to the pixel value of the pixel closest to the block boundary in the line of pixels and is subtracted from the pixel value of the pixel closest to the block boundary in the corresponding line of pixels. The resulting deblocking filter has good low-pass characteristics and is efficient for reducing blocking artifact.

主权项

1. A method of reducing blocking artifacts at a block boundary between a first block of multiple pixels and a neighboring block of multiple pixels in a video frame, said method comprises:
calculating a first offset to be based on (9×(q0−p0)−3×(q1−p1))/16, wherein p0 denotes a pixel value of a pixel closest to said block boundary in a line of pixels in said first block, wherein said line of pixels is perpendicular to said block boundary, p1 denotes a pixel value of a pixel next closest to said block boundary in said line of pixels, q0 denotes a pixel value of a pixel closest to said block boundary in a corresponding line of pixels in said neighboring block, wherein said corresponding line of pixels is perpendicular to said block boundary and q1 denotes a pixel value of a pixel next closest to said block boundary in said corresponding line of pixels; modifying said pixel value p0 of said pixel closest to said block boundary in said line of pixels by adding said first offset to said pixel value p0 of said pixel closest to said block boundary in said line of pixels to form a modified pixel value p0′ of said pixel closest to said block boundary in said line of pixels; and modifying said pixel value q0 of said pixel closest to said block boundary in said corresponding line of pixels by subtracting said first offset from said pixel value q0 of said pixel closest to said block boundary in said corresponding line of pixels to form a modified pixel value q0′ of said pixel closest to said block boundary in said corresponding line of pixels.