On Energy Compaction of 2D Saab Image Transforms

TL;DR

This paper evaluates the energy compaction of the Saab transform compared to DCT and KLT in HEVC intra-coding, demonstrating its effectiveness through extensive experiments.

Contribution

It provides the first comprehensive analysis of the Saab transform's energy compaction in image coding, comparing it with traditional transforms in the HEVC standard.

Findings

Saab transform shows comparable energy compaction to DCT and KLT.

Visualizations of Saab basis functions reveal interpretability.

Experimental results confirm Saab's potential in intra-coding efficiency.

Abstract

The block Discrete Cosine Transform (DCT) is commonly used in image and video compression due to its good energy compaction property. The Saab transform was recently proposed as an effective signal transform for image understanding. In this work, we study the energy compaction property of the Saab transform in the context of intra-coding of the High Efficiency Video Coding (HEVC) standard. We compare the energy compaction property of the Saab transform, the DCT, and the Karhunen-Loeve transform (KLT) by applying them to different sizes of intra-predicted residual blocks in HEVC. The basis functions of the Saab transform are visualized. Extensive experimental results are given to demonstrate the energy compaction capability of the Saab transform.