Image and Video Compression

142 Image and Video Compression

of the quality of the image is estimated by the absolute magnitude of the error

signal.

As a result, for the same error or noise, the distortion measure remains the

same. As discussed, if perceived image quality is good and PSNR is low, this

quality metric fails. In such a case, the image quality is judged based on the

HVS parameters such as contrast, luminance, and structural information.

Wang and Bovik (2004) designed a metric called the mean structural simi-

larity index measure (MSSIM), which performs well in such situations and

correlates well with perceived image quality by HVS.

7.4.3 Spectral Activity Mea ...