select_contours_xldselect_contours_xldSelectContoursXldSelectContoursXld (Operator)

Name

select_contours_xldselect_contours_xldSelectContoursXldSelectContoursXld — Select XLD contours according to several features.

Signature

Description

select_contours_xldselect_contours_xldSelectContoursXldSelectContoursXldSelectContoursXld selects XLD contours from the input contours ContoursContoursContoursContourscontours according to the following features (parameter FeatureFeatureFeatureFeaturefeature):

'contour_length'"contour_length""contour_length""contour_length""contour_length":

all contours whose length is smaller than Min1Min1Min1Min1min1 or larger than Max1Max1Max1Max1max1 are not returned (Min2Min2Min2Min2min2 and Max2Max2Max2Max2max2 have no influence here).

'maximum_extent'"maximum_extent""maximum_extent""maximum_extent""maximum_extent":

all contours whose maximum extent (as measured by their eight extremal points in row and column direction, according to Haralick and Shapiro: Computer and Robot Vision, Addison-Wesley 1992, chapter 3.2) is smaller than Min1Min1Min1Min1min1 or larger than Max1Max1Max1Max1max1 are not returned (Min2Min2Min2Min2min2 and Max2Max2Max2Max2max2 have no influence here).

'direction'"direction""direction""direction""direction":

only contours for which the direction of the regression line is between Min1Min1Min1Min1min1 and Max1Max1Max1Max1max1 (in radians, counter-clockwise) are returned. Min1Min1Min1Min1min1 and Max1Max1Max1Max1max1 are mapped to the range of [0,2*PI[. (Min2Min2Min2Min2min2 and Max2Max2Max2Max2max2 have no influence here).

'curvature'"curvature""curvature""curvature""curvature":

only contours for which the mean distance from the regression line lies between Min1Min1Min1Min1min1 and Max1Max1Max1Max1max1, and for which the standard deviation of the distances is between Min2Min2Min2Min2min2 and Max2Max2Max2Max2max2 are returned.

'closed'"closed""closed""closed""closed":

only contours for which the distance between their start point and their end point is less or equal Max1Max1Max1Max1max1 pixels are returned. (Min1Min1Min1Min1min1, Min2Min2Min2Min2min2 and Max2Max2Max2Max2max2 have no influence here.)

'open'"open""open""open""open":

only contours for which the distance between their start point and their end point is greater than Min1Min1Min1Min1min1 pixels are returned. (Max1Max1Max1Max1max1, Min2Min2Min2Min2min2 and Max2Max2Max2Max2max2 have no influence here).

If Min1Min1Min1Min1min1 = Max1Max1Max1Max1max1 = 0 or Min2Min2Min2Min2min2 = Max2Max2Max2Max2max2 = 0 is used for the selection according to curvature, the respective feature has no influence on the selection.

Attention

Before contour can be filtered by select_contours_xldselect_contours_xldSelectContoursXldSelectContoursXldSelectContoursXld according to 'direction' or 'curvature', the parameters of the regression lines to the contours must be calculated with regress_contours_xldregress_contours_xldRegressContoursXldRegressContoursXldRegressContoursXld. If this has not been done, select_contours_xldselect_contours_xldSelectContoursXldSelectContoursXldSelectContoursXld calls regress_contours_xldregress_contours_xldRegressContoursXldRegressContoursXldRegressContoursXld internally with the parameters Mode = 'no'"no""no""no""no" and Iterations = 1. If a different mode should be used, regress_contours_xldregress_contours_xldRegressContoursXldRegressContoursXldRegressContoursXld must be called explicitly.

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

Possible Predecessors

regress_contours_xldregress_contours_xldRegressContoursXldRegressContoursXldRegressContoursXld

See also

get_contour_xldget_contour_xldGetContourXldGetContourXldGetContourXld, get_contour_attrib_xldget_contour_attrib_xldGetContourAttribXldGetContourAttribXldGetContourAttribXld, gen_contours_skeleton_xldgen_contours_skeleton_xldGenContoursSkeletonXldGenContoursSkeletonXldGenContoursSkeletonXld, lines_gausslines_gaussLinesGaussLinesGaussLinesGauss, lines_facetlines_facetLinesFacetLinesFacetLinesFacet, edges_sub_pixedges_sub_pixEdgesSubPixEdgesSubPixEdgesSubPix, get_regress_params_xldget_regress_params_xldGetRegressParamsXldGetRegressParamsXldGetRegressParamsXld, get_contour_global_attrib_xldget_contour_global_attrib_xldGetContourGlobalAttribXldGetContourGlobalAttribXldGetContourGlobalAttribXld, query_contour_global_attribs_xldquery_contour_global_attribs_xldQueryContourGlobalAttribsXldQueryContourGlobalAttribsXldQueryContourGlobalAttribsXld

References

R. Haralick, L. Shapiro: “Computer and Robot Vision” Vol. 1; Kapitel 3.2, Addison-Wesley 1992

Module

Foundation