Bit Depth Optimization In DCT-IV for Extended JPEG

A discrete cosine transform (DCT) expresses a finite sequence of data points in terms of a sum of cosine functions oscillating at different frequencies. DCTs are vital to varied applications in science and engineering, from lossy compression of audio (e. g. MP3) and images (e. g. JPEG) (where small high-frequency components can be discarded to spectral ways for the numerical answer of partial differential equations. The modified discrete cosine transform (MDCT) is a lapped transform based on the type-IV discrete cosine transform (DCT-IV), with the additional property of being lapped it is designed to be performed on consecutive blocks of a larger dataset, wherever later blocks are unit overlapped so that the last half of one block coincides with the first half of the next block. Energy crisis in multimedia devices has resulted in poor quality of image/video resolution. These devices use compression standard, having Discrete Cosine Transform (DCT) as core computation intensive component. This work presents a novel approach to have an effective computation based on behavior of pixels, pixel approximation, and multiplicand value decision. We propose an energy aware computation driven approximate DCT architecture/compression. Reducing the simulation time by sacrificing the quality of an image with a new concept of error resilient. Further we introspect the computational time of matrix multiplications and coefficients scaling based on pixel behaviors. At last compare the results with new parameters like FSIM, SSIM etc.