The patients were presented blocks of 5 different digitally frozen video frames representing typical images encountered in movies. The order of the images within the block was randomized. Each block of images was presented a total of 4 times. Patients viewed the screen with their habitual optical correction used for TV viewing at home. Such interaction may be anticipated in consideration of the different spatial content which is relevant and interesting in different images.
Mean position correspond to mouse position on the bit pad.
Area to the left of that line represents image degradation by low-pass filtering. Area to the right represents enhancement. All patients selected values corresponding to enhancement. One patient was unable to manipulate the bit pad due to arthritis. In this group also patients never selected no enhancement or low-pass filtered images.