Image fidelity

Image fidelity, often referred to as the ability to discriminate between two images or how closely the image represents the real source distribution. Different from image quality, which is often referred to as the subject preference for one image over another, image fidelity represents to the ability of a process to render an image accurately, without any visible distortion or information loss. The two terms are often used interchangeably, but they are not the same.

If we cannot detect the difference between a photograph and a digitally printed image, we might conclude that the digital print has photographic image quality. But subjective impressions of image quality are much more difficult to characterize and, consequently, nearly impossible to quantify. It is not difficult to demonstrate that people use multiple visual factors or dimensions in complex non-linear combinations to make judgements about image quality. There are also significant individual differences in their judgements.