All-digital ring–wedge detector applied to image quality assessment
David M. Berfanger, Nicholas George · Applied Optics · 2000
In the automatic assessment of image quality we obtained a high accuracy in the classification of image degradations in a manner that is widely independent of scene content. Using an all-digital ring-wedge detector system combined with neural-network software, we conducted several experiments in which the end goal is to classify images according to numerical quality scales. Experiments are presented to stress the importance of both local and global image quality assessment. Two databases of degraded images were prepared. One uses five levels of Gaussian blur to simulate depth of field. The other was prepared with lossy compression and recovery with artifacts generated by a JPEG (Joint Photographic Experts Group) compression algorithm. In quantitative terms our best sorting of Gaussian blur without knowledge of the original scene was to an accuracy of 96%. For degradation using JPEG we obtained an accuracy of 95% without knowledge of the original and 98% when the original scene is available as a reference.