Coding of distortion-corrected fisheye video sequences using H.265/HEVC

TL;DR

This paper compares distortion correction before and after encoding fisheye videos using H.265/HEVC, showing pre-processing improves coding efficiency and video quality.

Contribution

It demonstrates that applying distortion correction as a pre-processing step enhances coding efficiency and quality for fisheye videos compared to post-processing.

Findings

Maximum PSNR gain of 1.91 dB for intra-frame coding

Average PSNR gains of 1.16 dB for intra-frame coding

Pre-processing improves coding efficiency and subjective quality

Abstract

Images and videos captured by fisheye cameras exhibit strong radial distortions due to their large field of view. Conventional intra-frame as well as inter-frame prediction techniques as employed in hybrid video coding schemes are not designed to cope with such distortions, however. So far, captured fish-eye data has been coded and stored without consideration to any loss in efficiency resulting from radial distortion. This paper investigates the effects on the coding efficiency when applying distortion correction as a pre-processing step as opposed to the state-of-the-art method of post-processing. Both methods make use of the latest video coding standard H.265/HEVC and are compared with regard to objective as well as subjective video quality. It is shown that a maximum PSNR gain of 1.91 dB for intra-frame and 1.37 dB for inter-frame coding is achieved when using the pre-processing method. Average gains amount to 1.16 dB and 0.95 dB for intra-frame and inter-frame coding, respectively.