Approximate SATD Hardware Accelerator Using the 8 × 8 Hadamard Transform
Matheus F. Stigger, Victor H. S. Lima, Leonardo Bandeira Soares, Cláudio Diniz, Sérgio Bampi · 2020
Sum of Absolute Transformed Differences (SATD) is a distortion metric based on the Hadamard Transform. It is used in current video encoders inside the refinement stage of motion estimation, which decides the best block of pixels to be used as prediction for each block to be encoded. To reduce the computational effort incurred by the SATD calculation, this work proposes an approximate SATD hardware accelerator by excluding columns of adders/subtractors of the 8 × 8 Hadamard Transform (HT). The proposed approximate accelerator reduces energy by up to 40.78% compared to the precise SATD accelerator.