Segment an image using an automatically determined threshold.

bin_threshold segments a single-channel gray value image using an automatically determined threshold. First, the relative histogram of the gray values is determined. Then, relevant minima are extracted from the histogram, which are used as parameters for a thresholding operation. In order to reduce the number of minima, the histogram is smoothed with a Gaussian, as in auto_threshold. The mask size is enlarged until there is only one minimum in the smoothed histogram. The selected region contains the pixels with gray values from 0 to the minimum. This operator is, for example useful for the segmentation of dark characters on a light paper.

read_image (Image, 'letters')
bin_threshold (Image, Seg)
connection (Seg, Connected)

bin_threshold is reentrant and automatically parallelized (on tuple level).

anisotropic_diffusion, median_image, illuminate

connection, select_shape, select_gray

auto_threshold, char_threshold

gray_histo, smooth_funct_1d_gauss, threshold

Foundation