A Quality Metric for High Dynamic Range

The Peak Signal to Noise Ratio (PSNR) metric has long been utilized for codec evaluation and development, and other uses. However, for High Dynamic Range (HDR), the PSNR metric is not suitable. A more appropriate characterization of coding and image quality is to split image brightness into ranges (such as factors of two), and then determine the standard deviation within each such range. Once the standard deviation (sigma) has been determined, the two sigma and above population of pixel differences is shown as percentages of pixels. This is necessary because codec pixel differences do not typically follow a normal Gaussian error distribution. The value of sigma at each brightness range, together with the percentage proportions of two sigma and above outliers, provides an appropriate quality metric system for HDR.

Published

2014-10

Content type

Original Research

Keywords

HDR, Sigma, PSNR, Outliers

DOI

10.5594/M001594

ISBN

978-1-61482-954-6