Visual Effects of Sampling in Digital Picture Processing-A Pilot Experiment

The perceptual significance of sampling distortions due to band limitation and aliasing was investigated. Sampling errors were investigated in two different scenes. A perceptual experiment comprising similarity judgements was designed. Four observers were asked to judge the similarity of pictures processed with different combinations of prefiltering and sampling frequency. The similarities were analyzed by a multidimensional scaing technique (INDSCAL). The obtained multidimensional solutions indicated that sampling distortions could be mapped in two perceptual dimensions. The perceptual dimensions were related both to the amount of aliasing and to band limitation. The subjective data indicated that the relative saliency of aliasing versus band limitation effects were different in the two scenes.