Low-Complexity Loeffler DCT Approximations for Image and Video Coding
Diego F. G. Coelho, Renato J. Cintra, Fábio M. Bayer, Sunera Kulasekera, Arjuna Madanayake, Paulo Martinez, Thiago L. T. da Silveira, Raíza S. Oliveira, Vassil S. Dimitrov · Journal of Low Power Electronics and Applications · 2018
This paper introduced a matrix parametrization method based on the Loeffler discrete cosine transform (DCT) algorithm. As a result, a new class of 8-point DCT approximations was proposed, capable of unifying the mathematical formalism of several 8-point DCT approximations archived in the literature. Pareto-efficient DCT approximations are obtained through multicriteria optimization, where computational complexity, proximity, and coding performance are considered. Efficient approximations and their scaled 16- and 32-point versions are embedded into image and video encoders, including a JPEG-like codec and H.264/AVC and H.265/HEVC standards. Results are compared to the unmodified standard codecs. Efficient approximations are mapped and implemented on a Xilinx VLX240T FPGA and evaluated for area, speed, and power consumption.