Banding vs. Quality: Perceptual Impact and Objective Assessment

TL;DR

This paper investigates the perceptual impact of banding artifacts in videos, compares it with other distortions, and proposes a combined quality metric that better aligns with human perception.

Contribution

It introduces a banding-aware video quality metric combining VMAF and CAMBI, improving correlation with perceived quality over existing metrics.

Findings

Banding significantly affects perceived video quality.

The combined metric outperforms individual metrics in correlation.

Banding detection remains challenging for traditional quality metrics.

Abstract

Staircase-like contours introduced to a video by quantization in flat areas, commonly known as banding, have been a long-standing problem in both video processing and quality assessment communities. The fact that even a relatively small change of the original pixel values can result in a strong impact on perceived quality makes banding especially difficult to be detected by objective quality metrics. In this paper, we study how banding annoyance compares to more commonly studied scaling and compression artifacts with respect to the overall perceptual quality. We further propose a simple combination of VMAF and the recently developed banding index, CAMBI, into a banding-aware video quality metric showing improved correlation with overall perceived quality.