Abstract
This paper describes an assimilation phenomenon on monochrome images divided from the size of patterns, and proposes an analytical model about this phenomenon. The frequency spectrum of a sample pattern by the discrete Fourier Transform and human visual characteristics by the Butterworth type Low Pass Filter (LPF) are formulized. A two-dimensional model of the relation between the samples and human visual characteristics, which is additionally introduced the concept of a noise level is proposed, and discussed with the assimilation phenomenon qualitatively and quantitatively. Then, a comparative examination of this model is carried out by subjective evaluation, using the visual distance, and the validity is verified. As a result, the analysis using this proposal model, the cut-off frequency of this LPF is set to 20 cycle/degree, its attenuance is set to -20 dB/decade, and the noise level presumes -50 dB. The results almost conformed qualitatively to the results of evaluation experiments in this example.
