Multiplierless 16-point DCT Approximation for Low-complexity Image and Video Coding

TL;DR

This paper introduces a novel 16-point approximate DCT that requires no multiplications or bit-shifts, using only 44 additions, and demonstrates superior performance and efficiency in image and video coding applications.

Contribution

The paper presents the first low-complexity, multiplication-free 16-point DCT approximation with a fast algorithm and hardware implementation, outperforming existing methods in efficiency and coding performance.

Findings

Achieves the lowest arithmetic cost with only 44 additions.

Provides the best cost-benefit ratio in image compression.

Shows 35-37% improvements in hardware metrics over previous transforms.

Abstract

An orthogonal 16-point approximate discrete cosine transform (DCT) is introduced. The proposed transform requires neither multiplications nor bit-shifting operations. A fast algorithm based on matrix factorization is introduced, requiring only 44 additions---the lowest arithmetic cost in literature. To assess the introduced transform, computational complexity, similarity with the exact DCT, and coding performance measures are computed. Classical and state-of-the-art 16-point low-complexity transforms were used in a comparative analysis. In the context of image compression, the proposed approximation was evaluated via PSNR and SSIM measurements, attaining the best cost-benefit ratio among the competitors. For video encoding, the proposed approximation was embedded into a HEVC reference software for direct comparison with the original HEVC standard. Physically realized and tested using FPGA hardware, the proposed transform showed 35% and 37% improvements of area-time and area-time-squared VLSI metrics when compared to the best competing transform in the literature.