Retinal DOG Filters: Effects of the Discretization Process

This paper aims at analyzing the effects of the discretization process of the continuous Difference-of-Gaussians models obtained empirically by Enroth-Cugell and Robson (1966). The filter properties of the Discrete DoG kernels were analyzed in the frequency domain and their effects on input images were characterized by means of GLCM descriptors. The results demonstrate that the DoG Kernels behaviour range between true High-Frequency Enhancing filters and Band-pass filters depending on the discretization parameters. Moreover, the analysis of filtered images suggest that those kernels that enhance contrast come at a cost of higher entropy as well as lower spatial correlation.