Stereo image compression - the importance of spatial resolution in half occluded regions

The author reports on the visibility of spatial details located in those regions of a stereo pair which are seen by one eye only. In normal viewing, these regions correspond to areas of a scene which are occluded by nearer objects for one eye or the other-so called half occluded regions (or monocular regions). It is assumed that the resolving power of human vision in binocular regions would be higher than that in half occluded regions because of the effect of binocular summation. If it were true, high spatial frequency components in half occluded regions could be reduced without impairment of the subjective image quality. A comparison test of the visual resolving power for spatially low-pass filtered and non-filtered patterns in half occluded regions was carried out. The experiment showed, however, that any impairment visible in binocular regions was also visible in half occluded regions. Thus the assumption has been falsified and for the purpose of stereo image coding no irrelevant data elimination can be carried out in half occluded regions.