JP2016082304A5

JP2016082304A5 -

Info

Publication number: JP2016082304A5
Application number: JP2014209220A
Authority: JP
Filing date: 2014-10-10
Publication date: 2017-02-23
Anticipated expiration: 2034-10-10

Claims

An offset correction unit that corrects an offset value to be applied to the reconstructed image based on an image feature amount for each block of the reconstructed image;
An offset unit for offsetting a pixel value of the reconstructed image with an offset value corrected by the offset correcting unit;
An image processing apparatus comprising:

The image feature amount includes an index related to flatness of each block,
The offset correction unit corrects the offset value so that a smaller offset value is applied to a flatter block;
The image processing apparatus according to claim 1.

The image processing apparatus according to claim 2, wherein the index relating to flatness includes one or more of a variance of pixel values, a standard deviation, and a first-order differential sum.

The image feature amount includes an index related to a loss of high frequency components in each block,
The offset correction unit corrects the offset value so that a smaller offset value is applied to a block with a smaller loss of high-frequency components.
The image processing apparatus according to claim 1.

The index related to the loss of the high-frequency component may be one or more of a ratio of sub-blocks whose transform coefficient is zero, a quantization parameter, and a ratio of sub-blocks whose motion compensation sample accuracy is a specific accuracy. The image processing apparatus according to claim 4, further comprising:

The image processing apparatus according to claim 5, wherein the offset correction unit corrects the offset value so that a smaller offset value is applied to a block having a larger ratio of sub blocks in which the transform coefficient is zero.

The image processing apparatus according to claim 6, wherein the correction strength by the offset correction unit is weakened as the value of the quantization parameter increases.

The image processing apparatus according to claim 5, wherein the offset correction unit corrects the offset value so that a smaller offset value is applied to a block having a smaller quantization parameter.

The image processing according to claim 5, wherein the offset correction unit corrects the offset value so that a smaller offset value is applied to a block having a larger proportion of sub-blocks in which the motion compensation sample accuracy is decimal accuracy. apparatus.

The image processing apparatus according to claim 1, wherein the image feature amount includes a proportion of sub-blocks having a motion vector of zero.

The image processing apparatus according to claim 10, wherein the offset correction unit corrects the offset value so that a smaller offset value is applied to a block having a larger proportion of sub-blocks in which the motion vector is zero.

The image processing apparatus further includes an offset determination unit that determines an offset value to be applied to the reconstructed image for each block based on rate distortion optimization,
The offset correction unit corrects the offset value determined by the offset determination unit based on the image feature amount;
The image processing apparatus according to claim 1 .

The offset determination unit selects an offset type for each block,
The offset correction unit corrects the offset value for a block in which the selected offset type is an edge offset;
The image processing apparatus according to claim 12.

Said offset portion skips offsetting the pixel values of the blocks belonging to the B picture or B-slice, the image processing apparatus according to any one of claims 1 to 13.

Said offset portion skips offsetting the pixel value of the motion vector is zero block or sub-block, the image processing apparatus according to any one of claims 1 to 14.

The image processing apparatus according to claim 1 , wherein the block corresponds to a CTB (Coding Tree Block).

Correcting an offset value to be applied to the reconstructed image based on an image feature amount for each block of the reconstructed image;
Offsetting the pixel value of the reconstructed image with the modified offset value;
An image processing method including:

An offset correction unit that corrects an offset value to be applied to the reconstructed image based on an image feature amount for each block of the reconstructed image;
An encoding unit for encoding the offset value corrected by the offset correction unit;
A decoding unit for decoding the modified offset value encoded by the encoding unit;
An offset unit for offsetting a pixel value of the reconstructed image with the corrected offset value decoded by the decoding unit;
An image processing system comprising: