blocking artifacts

(redirected from blocking artifact)

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 ?
Kim, "Adaptive blocking artifact reduction using wavelet-based block analysis," IEEE Transactions on Consumer Electronics, vol.
The LBT increases the coding gain and reduces the blocking artifact but it has more ringing artifacts.
4-(c), the blocking artifact always happens because of the codec operation which can affect the judgment of HVS to the VQ.
One of the main drawbacks of this method is that it produces blocking artifacts in the image.
The deblocking filter (DF) reduces blocking artifacts in encoded video sequences, and thereby significantly improves the subjective and objective quality of videos.
264/AVC deblocking filter successfully suppresses the blocking artifacts in HDV without significantly degrading the objective quality of video.
The BD-F7500's video processor includes a proprietary Samsung algorithm that improves the visual quality of block-based low bit-rate coded images and reduces blocking artifacts.
3(a) have fewer blocking artifacts and are more accurate especially at image edges.
It also features Dynamic Deblocking (DDb[TM]) which smoothes blocking artifacts that are common in MPEG encoded content.
However, DCT is not the best choice in image coding, because block DCT transform coding has serious blocking artifacts when the image is highly compressed at low bit rates.
Better picture quality, achieved by avoiding blocking artifacts and other visible problems caused by video compression algorithms.
It can be observed that edge and texture regions appear the obvious blurring and blocking artifacts.