Understanding and Removal of False Contour in HEVC Compressed Images

Qin Huang, Hui Yong Kim, W. J. Tsai, Se Yoon Jeong, Jin Soo Choi, C. C.Jay Kuo

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


A contour-like artifact called false contour is often observed in large smooth areas of decoded images and video. Without loss of generality, we focus on detection and removal of false contours resulting from the state-of-the-art High Efficiency Video Coding codec. First, we identify the cause of false contours by explaining the human perceptual experiences on them with specific experiments. Next, we propose a precise pixel-based false contour detection method based on the evolution of a false contour candidate (FCC) map. The number of points in the FCC map becomes fewer by imposing more constraints step by step. Special attention is paid to separating false contours from real contours such as edges and textures in the video source. Then, a decontour method is designed to remove false contours in the exact contour position while preserving edge/texture details. Extensive experimental results are provided to demonstrate the superior performance of the proposed false contour detection and removal method in both compressed images and videos.

Original languageEnglish
Article number7563448
Pages (from-to)378-391
Number of pages14
JournalIEEE Transactions on Circuits and Systems for Video Technology
Issue number2
StatePublished - 1 Feb 2018


  • Compression artifact
  • contouring artifact
  • decontour
  • false contour
  • High Efficiency Video Coding (HEVC)


Dive into the research topics of 'Understanding and Removal of False Contour in HEVC Compressed Images'. Together they form a unique fingerprint.

Cite this