JPEG is a lossy compression technique which is the default format for all major digital cameras and estimated to be used for over 80% of all digital images on the web [1], [2]. During JPEG encoding, quantization is used to approximate frequency coefficients by a set of integers called the quantization table. We introduce OptQT as a new framework for the optimal design of JPEG quantization tables.

JPEG is a widely used format for images. Most JPEG variants are based upon a block-based DCT transformation followed by quantization and entropy coding. Redundancy at row/column level is explored in [1]. Brunsli [2] and Lepton [3], lossless JPEG repacking libraries, explore redundancy at block level.