histo_2dim — Calculate the histogram of two-channel gray value images.
The operator histo_2dim calculates the 2-dimensional histogram of two images within Regions. The gray values of channel 1 (ImageCol) are interpreted as row index, those of channel 2 (ImageRow) as column index. The gray value at one point P(g1,g2) in the output image Histo2Dim indicates the frequency of the gray value combination (g1,g2) with g1 indicating the line index and g2 the column index.
Note that the operator histo_2dim only considers the given Regions and ignores any previously set domain of the input images.
Region in which the histogram is to be calculated.
Histogram to be calculated.
read_image(Image,'monkey') get_domain (Image, Domain) gauss_filter (Image, ImageGauss, 7) histo_2dim(Domain,ImageGauss, Image,Histo2Dim) dev_display(Histo2Dim)
If F is the plane of the region, the runtime complexity is O(F + 256^2).
The operator histo_2dim returns the value 2 (H_MSG_TRUE) if both images have defined gray values. The behavior in case of empty input (no input images available) is set via the operator set_system(::'no_object_result',<Result>:), the behavior in case of empty region is set via set_system(::'empty_region_result',<Result>:). If necessary an exception is raised.
decompose3, decompose2, draw_region
threshold, class_2dim_sup, pouring, local_max, gray_skeleton