Operator Reference
get_contour_global_attrib_xld (Operator)
get_contour_global_attrib_xld — Return global attributes values of an XLD contour.
Signature
Description
get_contour_global_attrib_xld returns the values of the
global attribute Name of the XLD contour Contour
in Attrib. Global attributes are additional values defined
for each contour.
query_contour_global_attribs_xld can be used to query which global
attributes are set for a particular contour.
The following list contains information about the different global contour attributes and the operators that add them to XLD contours:
- 'bright_dark'
-
The type of transition for each output XLD contour is stored in the attribute 'bright_dark'. It is set to 1.0, if the connecting line forms a bright-dark transition (left to right, viewed from start point to end point), otherwise it is set to 0.0.
The attribute 'bright_dark' is added by the following operator:
Exemplary XLD contours (red and green) along the edges of a rectification grid (direction from start to end point indicated by arrow head). The transition type, stored in the attribute 'bright_dark', is 1.0 for red contours and 0.0 for green contours. - 'cont_approx'
-
The best way to approximate a contour is stated by the attribute 'cont_approx': for 'cont_approx'=-1.0, the contour is best approximated by a line segment, for 'cont_approx'=0.0, by an elliptic arc, and for 'cont_approx'=1.0, by a circular arc.
The attribute 'cont_approx' is added by the following operator:
- 'is_hole'
-
For boundaries that enclose holes, the global contour attribute 'is_hole' is set to 1.0, otherwise, it is set to 0.0.
The attribute 'is_hole' is added by the following operators:
symm_difference_closed_contours_xld,difference_closed_contours_xld,intersection_closed_contours_xld,union2_closed_contours_xldApplying different set operations to XLD contours or contour sets adds the global attribute 'is_hole' to the resulting contour(s). In the example above, for two sets (red and green) of closed contours different set operations are performed. If a resulting boundary encloses a hole (blue contours), 'is_hole' is set to 1.0, otherwise the value of 'is_hole' is 0.0 (orange contours). - 'regr_dev_dist'
-
'regr_dev_dist' [px] gives the standard deviation of the (Euclidean) distances between the contour points and the regression line (see image below).
The attribute 'regr_dev_dist' is added by the following operator:
- 'regr_dist'
-
'regr_dist' [px] gives the minimal distance of the regression line from the origin of the image coordinate system (see image below).
The attribute 'regr_dist' is added by the following operator:
- 'regr_mean_dist'
-
The attribute 'regr_mean_dist' [px] contains the mean of the Euclidean distances between each contour point and the regression line (see image below).
The attribute 'regr_mean_dist' is added by the following operator:
- 'regr_norm_col'
-
'regr_norm_col' [px] is the column coordinate of the unit normal vector of the regression line with the normal vector pointing from the origin to the line (see image below).
The attribute 'regr_norm_col' is added by the following operator:
- 'regr_norm_row'
-
'regr_norm_row' [px] is the row coordinate of the unit normal vector of the regression line with the normal vector pointing from the origin to the line (see image below).
The attribute 'regr_norm_row' is added by the following operator:
Sketch of the attributes 'regr_dist', 'regr_norm_col', 'regr_norm_row' for the regression of an XLD contour (red). 'regr_mean_dist' and 'regr_dev_dist' are computed from the distances (black arrows) between the contour points and the regression line (solid black line).
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
Contour (input_object) xld_cont → object
Input XLD contour.
Name (input_control) string(-array) → (string)
Name of the attribute.
Default: 'regr_norm_row'
Suggested values: 'regr_norm_row', 'regr_norm_col', 'regr_mean_dist', 'regr_dev_dist', 'cont_approx', 'bright_dark', 'is_hole'
Attrib (output_control) real-array → (real)
Attribute values.
Possible Predecessors
lines_gauss,
lines_facet,
edges_sub_pix,
segment_contours_xld
Possible Successors
fit_circle_contour_xld,
fit_ellipse_contour_xld,
fit_line_contour_xld,
fit_rectangle2_contour_xld
See also
query_contour_global_attribs_xld,
get_contour_attrib_xld,
query_contour_attribs_xld
Module
Foundation