We compare the measured Wiener spectra of practical film graininess of radiographic granularity with theoretical results of the conventional random dot model and the extended random dot model which has been proposed previously. Comparing theoretical Wiener spectra and computer-generated random dot patterns with measured results, we found that whereas the extended random dot model can reproduce the experimental results in low frequency regions by using proper values of parameters of the model, the conventional random dot model cannot.
© 1989 Optical Society of America
Kazuo Tanaka and Takao Sasaki, "Image microstructure model of radiographic film granularity," Appl. Opt. 28, 3897-3901 (1989)