Toward a simplified perceptual quality metric for watermarking applications

Abstract

This work is motivated by the limitations of statistical quality metrics to assess the quality of images distorted in distinct frequency ranges. Common quality metrics, which basically have been designed and tested for various kind of global distortions, such as image coding may not be efficient for watermarking applications, where the distortions might be restricted on a very narrow portion of the frequency spectrum. We hereby want to propose an objective quality metric whose performances do not depend on the distortion frequency range, but we nevertheless want to provide a simplified objective quality metric in opposition to the complex Human Visual System (HVS) based quality metrics recently made available. The proposed algorithm is generic (not designed for a particular distortion), and exploits the contrast sensitivity function (CSF) along with an adapted Minkowski error pooling. The results show a high correlation between the proposed objective metric and the mean opinion score (MOS) given by observers. A comparison with relevant existing objective quality metrics is provided. © 2010 Copyright SPIE - The International Society for Optical Engineering.