How Many Bits Are Enough?

Carlson and Cohen suggest that 'the perfect image is one that looks like a piece of the world viewed through a picture frame.' They propose that the metric for the perfect image be the discriminability of the reconstructed image from the ideal image the reconstruction is meant to represent. If these two images, the ideal and the reconstruction are noticeably different, then the reconstruction is less than perfect. If they cannot be discriminated then the reconstructed image is perfect. This definition has the advantage that it can be used to define 'good enough' image quality. An image that fully satisfies a task's image quality requirements for example text legibility, is selected to be the standard. Rendered images are then compared to the standard. Rendered images that are indiscriminable from the standard are good enough. Test patterns and test image sets serve as standards for many tasks and are commonplace to the image communications and display industries, so this is not a new nor novel idea.