Relative luminance and figure-background segmentation problems: Using AMLA to avoid nondiscernible stimulus pairs in common and color blind observers

Four experiments evaluated AMLA temporal version accuracy to measure relative luminosity in people with and without color blindness and, consequently, to provide the essential information to avoid poor figurebackground combinations in any possible “specific screen-specific observer” pair. Experiment 1 showed that two very different apparatus, a sophisticated photometer and a common luxometer, provide equivalent measurements to compute: (1) screen gamma exponents and (2) relative luminance (Y/Yn) of achromatic but not of chromatic stimuli. Experiments 2, 3 and 4 showed that the psychophysical task of AMLA temporal version provided, for any stimulus type, accurate relative luminance measurements. They were: equivalent to standardised photometric measurements for common observers (Experiment 2); similar to the expected distortions for simulated (Experiment 2) and real (Experiment 3) aged tritanomalous observers; concordant with the expected distortions of protanope observers (Experiment 4).