JP2001224031A5 - - Google Patents

Description

[Title of the Invention] Filter Device

[0001]
Field of the Invention
The present invention is divided into blocks, and decode the orthogonal transform and quantization and coding the encoded data, a block His Mito mosquito noise generated in the decoded image obtained by the inverse quantization and inverse orthogonal transform The present invention relates to a filter device to be reduced.
[0002]

[0009]
The post filter unit 58 performs post filtering to reduce blocking His body and mosquito noise on the decoded image of the current frame which is the output from the adder 54, and outputs the decoded image to reduce noise.

[0012]
In view of these problems, the present invention provides a block distortion reduction filter and a mosquito noise reduction filter based on the presence or absence of coding of the current block, motion vectors, information of interframe / intraframe prediction, and the state of transform coefficients. Adaptively performs block on / off control of the previous frame and post-filtered decoded image of the previous frame, and reduces the amount of processing while obtaining a decoded image with reduced noise due to the post filter The present invention provides a filter device capable of improving the image quality.

[0013]
[Means for Solving the Problems]
According to the present invention, the prediction code of the block is provided with a filter means for decoding an image encoded for each block and filtering the decoded image, and a filter strength determination means for determining the filter strength at the time of the filtering. When the conversion mode is intra-frame prediction , the above problem is solved by setting a filter strength stronger than inter-frame prediction and filtering the block boundaries according to the filter strength .

[0057]
As described above, the post filter and the information on the inter-frame / in-frame prediction are adaptively controlled based on the presence / absence of coding and the second frame memory in which the image of the previous frame on which the post filter and the post filter are performed is stored. By doing this, it is possible to obtain a decoded image with reduced noise while reducing the amount of processing. That is, on / off control of the block distortion reduction filter and the mosquito noise reduction filter based on the presence / absence of coding execution of the current block, motion vector, information of inter / interframe prediction, and transform coefficient Since the block replacement by the postfiltered decoded image is performed adaptively, it is possible to obtain a noise-reduced decoded image by the postfilter while reducing the processing amount. Further, when the present embodiment is implemented as hardware, the reduction of the processing amount also has the effect of reducing the power consumption.

[0058]
【Effect of the invention】
As apparent from the above description, according to the present invention, by determining the filter strength based on the inter-frame / inter-frame predictive coding mode between blocks, the frame is compressed higher than the inter-frame prediction and the image quality is degraded. Since strong filtering is performed on block boundaries of intra prediction, block distortion can be effectively reduced.

Brief Description of the Drawings
FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.
FIG. 2 is an explanatory view showing processing of a post filter processing content control unit in the present invention;
FIG. 3 is a view for explaining an example of post-filter processing in the present invention.
FIG. 4 is a view showing the details of the configuration of a post filter unit in the present invention.
5 is a diagram illustrating the configuration of a block His viewed reduction filter according to the present invention.
FIG. 6 is a diagram for explaining the configuration of a mosquito noise reduction filter according to the present invention.
FIG. 7 is a block diagram showing a configuration of a conventional moving picture decoding apparatus.
[Description of the code]
DESCRIPTION OF SYMBOLS 1 ... Variable length decoding part, 2 ... Inverse quantization part, 3 ... Inverse orthogonal transformation part, 4 ... Adder, 5 ... 1st frame memory part, 6 ... Motion compensation estimation part, 7 ... Switch, 8 ... Post filter Processing content control unit, 9: post filter unit, 10: second frame memory unit, 11: output signal selection unit.

Claims (3)

The image processing apparatus further comprises: filter means for decoding an image encoded for each block and filtering the decoded image; and filter strength determination means for determining filter strength in the filtering, wherein the prediction coding mode of the block is intraframe prediction A filter apparatus characterized by setting a filter strength stronger than inter-frame prediction in the case of and filtering a block boundary according to the filter strength . The filter device according to claim 1, wherein the filter means changes pixel values sandwiching the block boundary to connect the block boundary smoothly, and uses the value as a pixel value after filtering . Said filter means based on the size of the pixels sandwiching the block boundary, the filter apparatus according to claim 1, wherein the obtaining the output pixel value of the filtering.