A novel Type-2 fuzzy directed hybrid post-filtering technique for efficient JPEG image artifact reduction

Image and video compression become very popular and intense field in recent decades, due to fast and high quality communication demand of visual information. Currently, JPEG and JPEG2000 are the most popularly used codec's for achieving image compression. Practically, on the low bit rate compression, it has been observed that the JPEG compressed images suffer from multifarious visual distortions. To address this problem effectively, this paper proposed an innovative Type-2 fuzzy directed hybrid post filtering technique, which is framed to suppress the artifacts generated in JPEG compressed images at low bit rate compression. The proposed technique addresses all three types of JPEG image artifacts: blocking, edges blurring, and aliasing. Furthermore, the proposed technique is structured with two stages to enhance the quality of JPEG compressed images. The first stage removes blocking artifacts using boundary smoothing and guided filtering techniques. The second stage reduces blurring and aliasing around the edges through Type-2 fuzzy directed local edge regeneration. To prove higher artifacts reduction efficiency of proposed work, a complete comparative performance evaluation with other existing JPEG artifact removal techniques has been also presented. This extensive performance analysis includes visual quality assessment of post-filtered images along with a subjective quality assessment on the basis of Peak Signal to Noise Ratio (PSNR) parameter. Performance evaluation illustrates that the proposed approach is efficient; provides PSNR improvement in the range of 0.2 to 1.1 dB as compared to the state of the art algorithms for all bitrates.