Tampere University of Technology

TUTCRIS Research Portal

Additional lossless compression of JPEG images based on BPG

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Details

Original languageEnglish
Title of host publicationImage Processing: Algorithms and Systems XVII
DOIs
Publication statusPublished - 13 Jan 2019
Publication typeA4 Article in a conference publication
Event17th Image Processing: Algorithms and Systems Conference, IPAS 2019 - Burlingame, United States
Duration: 13 Jan 201917 Jan 2019

Publication series

NameIS and T International Symposium on Electronic Imaging Science and Technology

Conference

Conference17th Image Processing: Algorithms and Systems Conference, IPAS 2019
CountryUnited States
CityBurlingame
Period13/01/1917/01/19

Abstract

The task of additional lossless compression of JPEG images is considered. We propose to decode JPEG image and recompress it using lossy BPG (Better Portable Graphics) codec based on a subset of the HEVC open video compression standard. Then the decompressed and smoothed BPG image is used for calculation and quantization of DCT coefficients in 8x8 image blocks using quantization tables of the source JPEG image. A difference between obtained quantized DCT coefficients and quantized DCT coefficients of the source JPEG image (prediction error) is calculated. The difference is lossless compressed by a proposed context modeling and arithmetical coding. In this way the source JPEG image is replaced by two files: compressed BPG image and the compressed difference which needed for lossless restoration of the source JPEG image. It is shown that the proposed approach provides compression ratios comparable with state of the art PAQ8, WinZip and STUFFIT file archivers. At the same time BPG images may be used for fast preview of compressed JPEG images.