Artifacts removal of compressed digital images by linear enhancement and filtering

Abstract

Digital images that are compressed by JPEG compression schemes are affected by compression artifacts. The blocking artifacts and the ringing artifacts are the commonly seen compression artifacts. These artifacts need to be removed when we decompress the image for various applications. The objective of this work is to remove these artifacts without degrading the image. These compression artifacts can be reduced by low pass filtering of compressed mages. Low pass filtering of images cause loss of information whereby the images get blurred or the clarity of images get reduced. In this work, compressed image is first enhanced using linear enhancement technique and the resulting enhanced image is filtered using Gaussian type filter. The enhanced artifacts are removed more effectively when filtering is done in the enhanced image domain. After the removal of compression artifacts the linear enhancement is removed by the inverse of the transform which is used for linearly enhancing the image. After the removal of artifacts images will be of good quality which can be used in application areas like analysis medical image, analysis of satellite image, remote sensing and product inspection in industry.