Luminance-Guided Chrominance Image Enhancement for HEVC Intra Coding

TL;DR

This paper introduces a luminance-guided neural network for enhancing chrominance images in HEVC intra coding, significantly improving compression quality and reducing bitrate.

Contribution

It presents a novel luminance-guided CNN with a gated recursive asymmetric-convolution block for chrominance enhancement in HEVC intra coding.

Findings

Achieves 28.96% BD-rate reduction for U images.

Achieves 16.74% BD-rate reduction for V images.

Demonstrates superior performance over standard HEVC.

Abstract

In this paper, we propose a luminance-guided chrominance image enhancement convolutional neural network for HEVC intra coding. Specifically, we firstly develop a gated recursive asymmetric-convolution block to restore each degraded chrominance image, which generates an intermediate output. Then, guided by the luminance image, the quality of this intermediate output is further improved, which finally produces the high-quality chrominance image. When our proposed method is adopted in the compression of color images with HEVC intra coding, it achieves 28.96% and 16.74% BD-rate gains over HEVC for the U and V images, respectively, which accordingly demonstrate its superiority.