JPEG is the prevailing compression algorithm used for digital images. Compression ratio and quality depend on quantization tables that are matrixes of 64 integers. The quality of compression for many applications has to be determined not by human judgment, but by software systems that perform some processing on compressed images, based on successfulness of such processing. Since there are many such applications, there is not unique best quantization table but it has to be selected for each application. Quantization table selection is intractable combinatorial problem that can be successfully solved by swarm intelligence metaheuristics. In this paper we present framework for application of the recently introduced firefly algorithm to the quantization table selection problem for different image similarity metrics.
JPEG algorithm; image compression; quantization table; swarm inelligence; firefly algorithm; optimization metaheuristicsI.