| Operators |
nonmax_suppression_amp — Suppress non-maximum points on an edge.
nonmax_suppression_amp(ImgAmp : ImageResult : Mode : )
nonmax_suppression_amp suppresses all points in the regions of the image ImgAmp whose gray values are not local (directed) maxima. In contrast to nonmax_suppression_dir, a direction image is not needed. Two modes of operation can be selected:
A point is labeled as a local maximum if its gray value is larger than or equal to the gray values within a search space of pm 5 pixels, either horizontally or vertically. Non-maximum points are removed from the region, gray values remain unchanged.
A point is labeled as a local maximum if its gray value is larger than or equal to the gray values of its eight neighbors.
Amplitude (gradient magnitude) image.
Image with thinned edge regions.
Select horizontal/vertical or undirected NMS.
Default value: 'hvnms'
List of values: 'hvnms', 'loc_max'
nonmax_suppression_amp returns 2 (H_MSG_TRUE) if all parameters are correct. The behavior with respect to the input images and output regions can be determined by setting the values of the flags 'no_object_result', 'empty_region_result', and 'store_empty_region' with set_system. If necessary, an exception is raised.
threshold, hysteresis_threshold
local_max, nonmax_suppression_dir
S.Lanser: “Detektion von Stufenkanten mittels rekursiver Filter nach
Deriche”; Diplomarbeit; Technische Universität München, Institut
für Informatik, Lehrstuhl Prof. Radig; 1991.
J.Canny: “Finding Edges and Lines in Images”; Report, AI-TR-720;
M.I.T. Artificial Intelligence Lab., Cambridge, MA; 1983.
Foundation
| Operators |