Low-bit-rate video coding method based on frame difference image

Abstract

The invention discloses a low-bit-rate video coding method based on a frame difference image. The low-bit-rate video coding method based on the frame difference image includes that inputting a video sequence, if the current input frame fn is the I frame image and not the last frame image, respectively reading components Y, Cb and Cr of the current frame fn and reference frame fn+1; acquiring the luminance component DY and chromaticity component DCb and DCr of the frame difference image; performing scale change to obtain the converted frame difference components RY, RCb and RCr; storing the components RY, RCb and RCr in sequence to synthesize into a new frame difference image DR; using the new frame difference image DR to replace the I frame image in an original video sequence, jointly forming a new video sequence with a P frame image and a B frame image, and serving as the coding object of an HEVC video encoder to perform normal video coding; otherwise, directly entering the HEVC video encoder to perform normal video coding; outputting code stream. The low-bit-rate video coding method based on the frame difference image realizes low-bit-rate video coding based on keeping the quality of the video reconstructed image, improves the video coding compression ratio, saves bit resource and alleviates the contradictions between the reconstructed image quality of the video coding and the coding resource occupancy.

Description

technical field [0001] The invention belongs to the technical field of video processing, and relates to a low bit rate video encoding method based on frame difference images. Background technique [0002] There are three encoding frame types in existing video encoding standards, namely: I frame, P frame and B frame. In actual coding, code stream structures such as IPPP, IBBB, and IPBP are usually selected, that is, most video frames are predictively coded for P frames or B frames. Although P-frame and B-frame coding can obtain higher compression ratio through forward prediction and bi-directional prediction respectively, the image quality of video reconstructed by P-frame and B-frame coding often depends on the coding precision of the corresponding I frame. Therefore, in order to ensure the image quality of the reconstructed video after decoding, it is usually appropriate to insert I frames to avoid the propagation of prediction errors in the encoding of P frames and B fram...

AI Technical Summary

Problems solved by technology

At present, in the video coding standard represented by the new generation international video coding standard HEVC (High Efficiency Video Coding), the I frame is usually compressed and coded according to the spatial correlation within the coding unit and between the coding units. Compared with frame and B frame coding, I frame coding will consume more bit resources

However, the high bit occupancy rate of I-frame coding becomes the main bottleneck to further improve the overall video coding compression ratio and save video coding bit resources.

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