An algorithm for improving the quality of compacted JPEG image by minimizes the blocking artifacts

TL;DR

This paper introduces a deblocking algorithm that reduces JPEG compression artifacts by detecting and smoothing block boundaries, improving image quality without excessive blurring.

Contribution

The proposed algorithm effectively minimizes blocking artifacts in JPEG images through edge detection and targeted filtering, outperforming previous smoothing approaches.

Findings

Significant reduction in blocky artifacts observed

Improved subjective and objective image quality

Effective preservation of high-contrast edges

Abstract

The Block Transform Coded, JPEG- a lossy image compression format has been used to keep storage and bandwidth requirements of digital image at practical levels. However, JPEG compression schemes may exhibit unwanted image artifacts to appear - such as the 'blocky' artifact found in smooth/monotone areas of an image, caused by the coarse quantization of DCT coefficients. A number of image filtering approaches have been analyzed in literature incorporating value-averaging filters in order to smooth out the discontinuities that appear across DCT block boundaries. Although some of these approaches are able to decrease the severity of these unwanted artifacts to some extent, other approaches have certain limitations that cause excessive blurring to high-contrast edges in the image. The image deblocking algorithm presented in this paper aims to filter the blocked boundaries. This is accomplished by employing smoothening, detection of blocked edges and then filtering the difference between the pixels containing the blocked edge. The deblocking algorithm presented has been successful in reducing blocky artifacts in an image and therefore increases the subjective as well as objective quality of the reconstructed image.