Rotationally symmetric vs. oriented frequency channels for the Hotelling observer: a comparison with human observers

摘要

This study investigated the inclusion of oriented channels into the Hotelling observer. The performances of the channelized Hotelling observer with rotationally symmetric channels (CHO_(RS)), the channelized Hotelling observer with rotationally oriented channels (CHO_(RO)), and human observers were compared for a simple signal detection task. There were four Gaussian signals-circular, elliptical horizontal, elliptical diagonal and elliptical vertical of equal maximum intensity and signal power. There were four types of lumpy backgrounds-circular, horizontal and vertical-created by filtering a zero-mean, white, Gaussian noise image. For the CHO_(RO), the CHO_(RS), and the human observers, detectability indices for each of the 16 combinations of signal and background were calculated. The CHO_(RS) and CHO_(RO) were equivalent for the images where the signal and background had the same orientation; however, the CHO_(RO) was more predictive of human performance overall. Neither the CHO_(RS) nor CHO_(RO) models were predictive of human performance for images of elliptical signals on circularly oriented backgrounds—a result that underscores the need for further refinement of the channel models.