"Perfect" displays and "perfect" image compression in space and time

Several topics connecting basic vision research to image compression and image quality are discussed: (1) A battery of about 7 specially chosen simple stimuli should be used to tease apart the multiplicity of factors affecting image quality. (2) A 'perfect' static display must be capable of presenting about 135 bits/min2. This value is based on the need for 3 pixels/min and 15 bits/pixel. (3) Image compression allows the reduction from 135 to about 20 bits/min2 for perfect image quality. 20 bit/min2 is the information capacity of human vision. (4) A presumed weakness of the JPEG standard is that it does not allow for Weber's Law nonuniform quantization. We argue that this is an advantage rather than a weakness. (5) It is suggested that all compression studies should report two numbers separately: the amount of compression achieved from quantization and the amount from redundancy coding. (6) The DCT, wavelet and viewprint representations are compared. (7) Problems with extending perceptual losslessness to moving stimuli are discussed. Our approach of working with a 'perfect' image on a 'perfect' display with 'perfect' compression is not directly relevant to the present situation with severely limited channel capacity. Rather than studying perceptually lossless compression we must carry out research to determine what types of lossy transformations are least disturbing to the human observer. Transmission of 'perfect', lossless images will not be practical for many years.