Coding distortion removal method, video encoding method, video decoding method, and apparatus and program for the same

Abstract

Mosaic-shaped block noise occurs when a compressed video signal is reproduced. This block noise is removed, but removing block noise from every block using a deblocking filter imposes a significant load on the deblocking filter. This load is therefore reduced by determining whether coding distortion removal (deblocking) is necessary, and applying a deblocking filter only when needed.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of pending U.S. patent application Ser. No. 10 / 451,628, filed Jul. 8, 2003, which is a U.S. National Stage of PCT application PCT / JP02 / 12488, filed on Nov. 29, 2002, and claims the benefit of U.S. Provisional Application No. 60 / 333,763, filed Nov. 29, 2001, U.S. Provisional Application No. 60 / 333,767, filed Nov. 29, 2001, and U.S. Provisional Application No. 60 / 394,312, filed Jul. 9, 2002, as well as Japanese Application Nos. 2002-008859, filed Jan. 17, 2002, 2002-110748, filed Apr. 12, 2002, 2002-127101, filed Apr. 26, 2002, and 2002-291264, filed Oct. 3, 2002, the disclosures of which are expressly incorporated herein by reference in their entireties.TECHNICAL FIELD [0002] The present invention relates to a coding distortion removal method for removing coding distortion that occurs when encoding a video signal, an encoding method and a decoding method for increasing the compression rate using this cod...

AI Technical Summary

Benefits of technology

"The present invention provides a simple coding distortion removal method that can efficiently remove coding distortion from an image signal containing coding distortion. The method uses different methods to remove coding distortion at boundaries where the motion compensation unit boundary matches the coding unit boundary and at boundary positions where the motion compensation block size is larger than the coding block size. By using these methods, the likelihood of degrading image signal quality can be reduced. The method also uses picture parameters to identify the pixels that need to be processed for coding distortion removal, reducing the processing required. The invention also provides a coding distortion removal method for removing coding distortion in an area disposed on both sides of a block boundary between adjacent blocks in a picture having a plurality of blocks. This method uses a combination of quantization parameters and a threshold value to determine the appropriate method for removing coding distortion. The invention also provides a moving picture coding apparatus that uses plural reference images obtained by removing coding distortion to increase the compression rate of moving picture coding."

Problems solved by technology

The conventional coding distortion removal methods described above are particularly effective at removing coding distortion, but the process is extremely complex and implementation difficult.

A further problem is that the amount of data processed per unit time is high.

Furthermore, no matter how effective the coding distortion removal method, it is impossible to accurately distinguish image signals and coding distortion without other additional information, and there is, therefore, the possibility that coding distortion removal will degrade image quality.

This problem is particularly great with a configuration as shown in the block diagram in FIG. 33 of a video decoder using a conventional decoding method because the result of deblocking is used as the reference image and therefore affects the result of coding each subsequent picture.

Images