blocking artifacts


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blocking artifacts

A distortion that appears in compressed video material as abnormally large pixel blocks. Also called "macroblocking," it occurs when the encoder cannot keep up with the allocated bandwidth. It is especially visible with fast motion sequences or quick scene changes.

Video uses lossy compression, and the higher the compression rate, the more content is removed. At decompression, the output of certain decoded blocks makes surrounding pixels appear averaged together and look like larger blocks. As TVs get larger, blocking and other artifacts become more noticeable. See artifact and pixelated.


Before and After
The lines at the edge of the original frame are used to point to the blocking artifacts, which are removed with Algolith's MPEG Noise Reduction system. Both images are enlarged to show details. (Image courtesy of Algolith inc., www.algolith.com)
References in periodicals archive ?
Consequently, videos encoded using the HEVC standard may suffer from blocking artifacts, ringing, color deviations, and image blurring.
Blocking artifacts are discontinuities caused by encoding at the block boundary of the reconstructed picture, and seriously affect the subjective quality of videos.
Key words: high definition video, blocking artifacts, deblocking filter, H.
2003; Raja and Mirza, 2004) However, during compression process, loss of correlation between adjacent blocks during quantization process results in visually disturbing artifacts called blocking artifacts.
On the one hand, the blocking artifacts seriously affect the visual quality of the image.
The image deblocking method based on image enhancement does not consider the cause of blocking artifacts and only conducts image enhancement operation, such as spatial filtering [6], [7] and frequency domain filtering [8], [9].
Removal of Blocking artifacts in DC and AC filtering", IEEE Conference on Signal Processing, 1: 229-232.
The cause of blocking artifacts in lossy compression is artificial boundaries between neighboring blocks induced by BDCT.
So the efficiency problem of conventional APBT algorithm and the blocking artifacts in DCT can be solved by the parallel APBT algorithm.
10) and effectively remove the blurring and blocking artifacts in edge and texture regions.
Whereas block edges may not always be consistent with the heterogeneous object edges, and thus blocking artifacts are usually perceived in the regions where one block has a significantly different motion compared with its neighbors.
The visibility strength of the blocking artifacts for the horizontal direction ([V.