To quantizing method and the device of image
To quantizing method and the device of image
 CN 101,771,868 B
 Filed: 12/31/2008
 Issued: 03/02/2016
 Est. Priority Date: 12/31/2008
 Status: Active Grant
First Claim
1. to a quantizing method for image, it is characterized in that, comprising:
 Image block is converted, obtains the transform coefficient matrix of correspondence image block;
According to the dividing mode preset, Region dividing process is carried out to described transform coefficient matrix;
Add up the statistical value of the regional marked off;
Carry out quantification adjustment according to the statistical value in region and the priori data of corresponding region to region corresponding in the transform coefficient matrix of image block, the priori data of described corresponding region is the statistical value obtained by the coefficient of the corresponding region in the transform coefficient matrix of the image block in the image in statistics selected digital image sequence.
Chinese PRB Reexamination
Abstract
The embodiment of the invention discloses a kind of quantizing method to image and device thereof, with on the basis more simply, not affecting coding/decoding system performance, improve the subjective quality quantizing encoded images.The method comprises and converting image block, obtains the transform coefficient matrix of correspondence image block; According to the dividing mode preset, Region dividing process is carried out to described transform coefficient matrix; Add up the statistical value of the regional marked off; Statistical value according to region carries out quantification adjustment to region corresponding in the transform coefficient matrix of image block.
11 Claims

1. to a quantizing method for image, it is characterized in that, comprising:

Image block is converted, obtains the transform coefficient matrix of correspondence image block; According to the dividing mode preset, Region dividing process is carried out to described transform coefficient matrix; Add up the statistical value of the regional marked off; Carry out quantification adjustment according to the statistical value in region and the priori data of corresponding region to region corresponding in the transform coefficient matrix of image block, the priori data of described corresponding region is the statistical value obtained by the coefficient of the corresponding region in the transform coefficient matrix of the image block in the image in statistics selected digital image sequence.


2. the method for claim 1, is characterized in that, the statistical value of the regional that described statistics marks off comprises:

The mean value of the absolute value of the conversion coefficient comprised in each region marked off in computed image, as the statistical value of corresponding region;
OrThe variance of the conversion coefficient comprised in each region marked off in computed image, as the statistical value of corresponding region.


3. the method for claim 1, is characterized in that, described priori data obtains in the following way:
In advance for selected digital image sequence, first count the first mean value of the absolute value of the conversion coefficient of each diagonal zones in the corresponding each zoning of each image block of each image, and then add up second mean value of described first mean value of all image blocks of each image, and then add up the 3rd mean value of described second mean value of all images in described selected digital image sequence, and then calculate described 3rd mean value numerical value and, and then calculate described 3rd mean value and described numerical value and ratio, last the 4th mean value calculating described ratio for all video sequences in typical image sequence, as described priori data.

4. the method as described in claim 13 any one, is characterized in that, by following account form, carries out quantification adjustment to region corresponding in the transform coefficient matrix of image block:

WQk′
＝
WQk×
(1+α
·
(afkafk′
)/afk)In the transform coefficient matrix of wherein WQk '"'"' representative image block, index value is the coefficient value after the quantification regulation coefficient adjustment in the region of k; In the transform coefficient matrix of WQk representative image block, index value is the coefficient value before the quantification regulation coefficient adjustment in the region of k; The index value in region corresponding in k representation transformation coefficient matrix; α
representative quantizes the amplitude of regulation coefficient more new change;Afk is that in the transform coefficient matrix of image block, index value is the statistical value in the region of k; Afk '"'"' is the priori data in the region of k for index value.


5. method as claimed in claim 1 or 2, is characterized in that, described image block is through dividing the block obtained before Image Coding, or
It is the block that image obtains through division through the residual image that estimation obtains.

6. a method for image procossing, is characterized in that, specifically comprises:

Image block is converted, obtains the transform coefficient matrix of correspondence image block; According to the dividing mode preset, Region dividing process is carried out to described transform coefficient matrix; Add up the statistical value of the regional marked off; According to the statistical value of regional in the transform coefficient matrix of the last width of present image or the image block of multiple image, with the statistical value of the regional of the image block of present image, by following account form, determine that in the transform coefficient matrix of the image block of next image of present image, index value is the statistical value in the region of k; afk′
＝
α
·
(afk1afk0)Wherein afk '"'"' represents index value in the transform coefficient matrix of image block corresponding to next image is the statistical value in the region of k; K represents the index value in each region, and α
representative quantizes the amplitude of regulation coefficient more new change;Afk1 represents the statistical value in each region in transform coefficient matrix corresponding to the image block of present image; It is the statistical value of the region unit of k that afk0 represents index value in the last width of present image or the image block transform coefficient matrix of multiple image; Be that the statistical value in the region of k and the priori data of corresponding region carry out quantifications adjustment to region corresponding in the transform coefficient matrix of image block according to index value in the transform coefficient matrix of the image block of next image of present image, the priori data of described corresponding region is the statistical value that the coefficient of corresponding region in the transform coefficient matrix of image block in the image by adding up in selected digital image sequence obtains.


7. method as claimed in claim 6, it is characterized in that, described present image is current encoded image;

The last width of described present image or multiple image are the front one or more encoded image of current encoded image; Next image described is next image to be encoded of current encoded image.


8. method as claimed in claim 6, it is characterized in that, described present image is current decoded picture;

The last width of described present image or multiple image are the front one or more decoded picture of current decoded picture; Next image described is or next image to be decoded of current decoded picture.


9. , to a quantification treatment device for image, it is characterized in that, comprising:

Converter unit, for converting image block, obtains the transform coefficient matrix of correspondence image block; Division unit, for carrying out Region dividing process according to the dividing mode preset to the described transform coefficient matrix that described converter unit obtains; Statistic unit, for adding up the statistical value of the regional that described division unit marks off; Adjustment unit, for carrying out quantification adjustment according to the statistical value in region and the priori data of corresponding region to region corresponding in the transform coefficient matrix of image block, the priori data of described corresponding region is the statistical value obtained by the coefficient of the corresponding region in the transform coefficient matrix of the image block in the image in statistics selected digital image sequence.


10. device as claimed in claim 9, is characterized in that, the mean value of the absolute value of conversion coefficient of described statistic unit specifically for comprising in region marked off each in computed image, as the statistical value of corresponding region;
 Or
The variance of the conversion coefficient comprised in each region marked off in computed image, as the statistical value of corresponding region.
 Or

11. devices as described in claim 9 or 10, is characterized in that, described adjustment unit specifically for by following account form, carries out quantifications adjustment to region corresponding in the transform coefficient matrix of image block:

WQk′
＝
WQk×
(1+α
·
(afkafk′
)/afk)In the transform coefficient matrix of wherein WQk '"'"' representative image block, index value is the coefficient value after the quantification regulation coefficient adjustment in the region of k; In the transform coefficient matrix of WQk representative image block, index value is the coefficient value before the quantification regulation coefficient adjustment in the region of k; The index value in region corresponding in k representation transformation coefficient matrix; α
representative quantizes the amplitude of regulation coefficient more new change;Afk is that in the transform coefficient matrix of image block, index value is the statistical value in the region of k; Afk '"'"' is the priori data in the region of k for index value.

Specification(s)