A deblocking filter is a video filter applied to decoded compressed video to improve visual quality and prediction performance by smoothing the sharp edges which can form between macroblocks when block coding techniques are used. The filter aims to improve the appearance of decoded pictures.

What is a deblocking filter used for?

The deblocking filter reduces the blocking artifacts (visible discontinuities in an image) caused by block-based encoding with strong quantization. It is applied by modifying samples along horizontal and vertical boundaries of PUs and TUs. Filtering is applied separately in P and Q blocks, as shown in figure 3.

What is deblocking in VLC?

Deblocking is one type of post-processing that makes video or images appear less pixellated by rearranging pixels and hues to emulate contours of curves.