Model of Roberts effect in noisy images : evaluation and quantification

Abstract

The Roberts effect in noisy quantized images is explained. This effect produces the apparently contradictory fact that a better perceived quality of a quantized picture is obtained when noise is added. It is proposed that this effect is due to the action of a visual spatial filter, which consequently provokes the apparition of Mach bands. An experimental setup has been developed to quantify the model. Results show that the Roberts effect can be well explained by said filtering. An evaluation of the effect in terms of error function is also carried out.