Method and device for scaling motion vectors, and method and system for coding/decoding

Abstract

The embodiment of the invention relates to a method and a device for scaling motion vectors, and a method and a system for coding/decoding. The method for scaling motion vector comprises that: according to the amount of coordinate offset between a bottom field and a top field of an interlaced scanned image, coordinate transformation is performed on a first motion vector so as to obtain a second motion vector; the second motion vector is scaled so as to obtain a third motion vector; and according to the amount of coordinate offset, coordinate inverse transformation is performed to the third motion vector so as to obtain a fourth motion vector. The embodiment of the invention performs half-pixel compensation or coordinate transformation on the motion vectors before and after being scaled according to the offset of a top-field image and a bottom-field image in spatial positions, transforms a coordinate into a coordinate system reflecting the actual position relation of the images, and then scales the motion vector, thereby having the advantages of according with motion models better, guaranteeing the accuracy of scaling the motion vectors, raising the precision of predicting the motion vectors and improving the efficiency of coding and compressing field images.

Description

technical field [0001] The present invention relates to the field of multimedia technologies, in particular to a motion vector scaling method and device, and a codec method and system. Background technique [0002] In the video coding compression standard, the motion vector prediction technology is adopted to reduce the bit overhead required to transmit the motion vector. Motion vector prediction techniques include spatial motion vector prediction and temporal motion vector prediction. In spatial motion vector prediction, the motion vector of the current macroblock can be predicted according to the motion vectors of the adjacent macroblocks in space; while in time domain motion vector prediction, the motion vector of the current macroblock can be predicted according to the The motion vector of the current macroblock is predicted by the motion vectors of adjacent or close macroblocks on the time axis. [0003] Motion vector scaling is commonly used in motion vector predicti...

AI Technical Summary

Problems solved by technology

However, since the field image is different from the frame image, there is a spatial position offset (offset of half a pixel) between the top field and the bottom field of the field image, and the same motion vector scaling process as the frame image scaling will reduce the motion Accuracy of vector scaling, resulting in reduced encoding compression efficiency for field images

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