Method for coding session video by combining time domain dependence of face region and global rate distortion optimization

Abstract

The invention discloses a method for coding a session video by combining the time domain dependence of a face region and global rate distortion optimization. The distortion of a face region of interest (ROI) and diffusion influence thereof are estimated in advance by utilizing the time domain dependence of the face ROI between adjacent coded fames in the same group of pictures (GOP), and an effective auxiliary means is provided for optimal motion vector and mode division and selection. According to the method, the optimization of a coded unit of the face ROI is particularly emphasized from an overall point of view, so that the subjective and objective quality of the coded unit of the face ROI and subsequent coded units taking the coded unit of the face ROI as a reference is well ensured, additional bit overhead caused by the distortion diffusion in the conventional coding process is avoided, and on the premise of maintaining or improving the subjective and objective quality of a coded picture, the coding rate of the session video is effectively decreased, and coding performance is improved; and the method is completely compatible with the conventional sequential coding structure, and is applied to application places such as video storage, real-time video coding with requirements on real-time performance of more than a GOP delay, and the like.

Description

Technical field

[0001] The invention belongs to the field of video coding and processing, and in particular relates to the research on the rate-distortion optimization coding method in the session video coding process. Background technique

[0002] As one of the key features that distinguish human beings from other creatures, the human face plays the role of the main information carrier in interpersonal communication and social activities. Therefore, a comprehensive and in-depth study of it has very important theoretical and practical significance. With the rise of real-time multimedia services, applications such as video conferences, videophones, and news broadcasts are directly or indirectly related to human faces. With the widespread promotion of these applications, the importance of face research is increasing day by day. Usually, the video coding and communication circles use "session video sequence" to summarize the above applications, and the corresponding coding tec...

Examples

Embodiment Construction

[0060] The present invention will be further described below in conjunction with drawings and embodiments.

[0061] For the convenience of explanation and without loss of generality, the following assumptions are made for the video sequence of the session to be coded:

[0062] Assume that the coding unit size is 16*16;

[0063] Assuming that the resolution of the coded image is 352*288, the number of coding units is 22*18, numbered sequentially from 1 to 396 in row order;

[0064] Assume that the total number of encoded frames is 100, and the GOP size is 5;

[0065] It is assumed that each coded frame can perform face detection according to an appropriate face detection method.

[0066] Based on the above assumptions, this embodiment takes the first GOP as an example for introduction.

[0067] A. Perform face ROI detection on all coded frames in the current GOP, so as to determine the specific position of the face ROI coding unit. Suppose the sequence number of the face RO...

Technical field

[0001] The invention belongs to the field of video coding and processing, and in particular relates to the research on the rate-distortion optimization coding method in the session video coding process. Background technique

[0002] As one of the key features that distinguish human beings from other creatures, the human face plays the role of the main information carrier in interpersonal communication and social activities. Therefore, a comprehensive and in-depth study of it has very important theoretical and practical significance. With the rise of real-time multimedia services, applications such as video conferences, videophones, and news broadcasts are directly or indirectly related to human faces. With the widespread promotion of these applications, the importance of face research is increasing day by day. Usually, the video coding and communication circles use "session video sequence" to summarize the above applications, and the corresponding coding tec...

Examples

Embodiment Construction

[0060] The present invention will be further described below in conjunction with drawings and embodiments.

[0061] For the convenience of explanation and without loss of generality, the following assumptions are made for the video sequence of the session to be coded:

[0062] Assume that the coding unit size is 16*16;

[0063] Assuming that the resolution of the coded image is 352*288, the number of coding units is 22*18, numbered sequentially from 1 to 396 in row order;

[0064] Assume that the total number of encoded frames is 100, and the GOP size is 5;

[0065] It is assumed that each coded frame can perform face detection according to an appropriate face detection method.

[0066] Based on the above assumptions, this embodiment takes the first GOP as an example for introduction.

[0067] A. Perform face ROI detection on all coded frames in the current GOP, so as to determine the specific position of the face ROI coding unit. Suppose the sequence number of the face RO...

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