local_max_contours_xld🔗
Short description🔗
local_max_contours_xld — Select XLD contours with a local maximum of gray values.
Signature🔗
local_max_contours_xld( xld_cont Contours, image Image, out xld_cont LocalMaxContours, number MinPercent, integer MinDiff, integer Distance )
Description🔗
local_max_contours_xld selects XLD contours from the
contours passed in Contours, which have a local maximum
in gray values across the direction of the contour. In order to be
selected, at least MinPercent of the contour points must
have a local maximum perpendicular to the direction of the contour.
The contours’ direction is determined by fitting a regression line
through five neighboring points of the contour. In order to decide
whether there is a local maximum for a contour point, a gray value
profile that is Distance points wide and perpendicular to the
contour is computed on both sides of the contour. If the gray value
at the contour point is at least MinDiff larger than the
gray value at at least one point on each side of the profile, the
contour point is labeled as a local maximum. The selected contours
are returned in LocalMaxContours.
Execution information🔗
Execution information
-
Multithreading type: reentrant (runs in parallel with non-exclusive operators).
-
Multithreading scope: global (may be called from any thread).
-
Processed without parallelization.
Parameters🔗
Contours (input_object) xld_cont-array → object
XLD contours to be examined.
Image (input_object) singlechannelimage → object (byte)
Corresponding gray value image.
LocalMaxContours (output_object) xld_cont-array → object
Selected contours.
MinPercent (input_control) number → (integer / real)
Minimum percentage of maximum points.
Default: 70
Suggested values: 60, 70, 75, 80, 85, 90, 95
Restriction: 0.0 <= MinPercent && MinPercent <= 100.0
MinDiff (input_control) integer → (integer)
Minimum amount by which the gray value at the maximum must be larger than in the profile.
Default: 15
Suggested values: 5, 8, 10, 12, 15, 20
Restriction: 0 <= MinDiff && MinDiff <= 255
Distance (input_control) integer → (integer)
Maximum width of profile used to check for maxima.
Default: 4
Suggested values: 2, 3, 4, 5, 6
Restriction: Distance >= 1
Combinations with other operators🔗
Combinations
Possible predecessors
gen_contours_skeleton_xld, lines_gauss, lines_facet, edges_sub_pix
Possible successors
See also
Module🔗
Foundation