Quantisation table used in joint photographic experts group JPEG standard plays a major role in the trade-off between the compression and quality of the image. Hence, finding a quantisation table is inferred as an optimisation problem. This paper proposes a classical differential evolution CDE algorithm for finding the optimal luminance quantisation table for a target bits/pixel bpp. Also, it aims to carry out an extensive performance comparison of the CDE algorithm with the classical genetic algorithm CGA. It is observed that the CDE-based quantisation table outperforms the default JPEG and CGA-based quantisation tables in terms of mean squared error MSE and peak signal to noise ratio PSNR. Images with different complexity levels have been experimented with both CDE and CGA algorithms. The validation results show that CDE guarantees a feasible solution in faster convergence rate than CGA. The results are confirmed using the statistical hypothesis test t-test.
['Balasubramanian Vinoth Kumar', 'M. Karpagam']
Differential evolution versus genetic algorithm in optimising the quantisation table for JPEG baseline algorithm