Accession Number : ADA112436

Title :   Spatial Frequency Masking and Visibility.

Descriptive Note : Annual rept. no. 2, FY 81,


Personal Author(s) : Smith,Robert A

PDF Url : ADA112436

Report Date : 15 Jan 1982

Pagination or Media Count : 37

Abstract : In the past year, work has progressed in four interrelated areas. (1) Substantial, evidence supports the hypothesis that visual detection in the presence of masking noise occurs at a constant signal/noise ratio only if the subject is unfamiliar with the mask. (2) The computerized model of visual masking now incorporates enhancement by sub-threshold masks and spatial frequency tuning, in addition to (1), above. (3) Spatial adaptation studies provide a better estimate of channel bandwidth than was previously available. This appears, however, to represent an altogether different mechanism from that involved in masking. (4) Attempts to confirm studies showing the existence of two separate visual systems for the processing of spatial and temporal information have failed even to replicate published effects. The reason for this is still under investigation. (Author)

Descriptors :   *Optical images, *Spatial filtering, *Masking, *Signal to noise ratio, Cathode ray tube screens, Predictions, Tuning, Adaptation, Bandwidth, Channels, Threshold effects, Computerized simulation, Target acquisition, Target detection, Contours, Arrays, Interactions

Subject Categories : Printing and Graphic Arts
      Optical Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE