Fig. 2.

Example simulated CRs. Top row: example images used during model training and for the validation set. Left column: different values of Gaussian amplitude A. Right column: different pixel noise values ${\sigma }_n^2$ (image levels). For both columns, random positions (within $[-1.5r,1.5r]$) and orientations of the dividing line between the dark and light sections of the background are shown. Bottom row: example images used for evaluation, showing different background locations E as well as a CR image without a gray background. The value for the varied parameter is denoted on the panels. A was set to 10000 for all panels except the top-left. For illustration purposes, the CR radius (r) in these panels is 50 pixels. During both training and evaluation, the pixel intensity of the lighter section of the background was also varied (not shown)