Human Visual System models (which several ones can be found in the literature) are responding to the physics and features of human eye perception features. They are based on elementary Heinemann's experience, which proved the nonlinear relation between luminance (physical luminous intensity) and brightness (subjective luminous intensity) of a tested image perceived by the HVS.This paper presents the comparison of several HVS models applied to own designed test image with special areas for machine valuation. It presents the results of applying these models (by the histogram modification method) to the model image and analyzing values of Ink Jet hardcopy outputs comparing to the original one. After all the best HVS model is introduced and a new test algorithm to the digital valuation.