select_lines

Herror ::select_lines ( const HTuple &RowBeginIn, const HTuple &ColBeginIn, const HTuple &RowEndIn, const HTuple &ColEndIn, const HTuple &Feature, const HTuple &Operation, const HTuple &Min, const HTuple &Max, HTuple *RowBeginOut, HTuple *ColBeginOut, HTuple *RowEndOut, HTuple *ColEndOut )

Select lines according to various criteria.

The operator ::select_lines chooses lines according to various criteria. For every input line the indicated features (Feature) are calculated. If each (Operation = 'and') or at least one (Operation = 'or') of the calculated features is within the given limits (Min,Max) the line is transferred into the output.

Condition:   Min_i <= Feature_i(Line) <= Max_i

Possible values for Feature:
  - 'length'       (Euclidean) length of the line
  - 'row'          Line index of the center
  - 'column'       Column index of the center
  - 'phi'          Orientation of the line (-pi/2 < phi <= pi/2)

Attention

If only one feature is used the value of Operation is meaningless. Several features are processed according to the sequence in which they are passed.

Parameters

`RowBeginIn` (input_control)	line.begin.y-array `->` HTuple.long
Row coordinates of the starting points of the input lines.

`ColBeginIn` (input_control)	line.begin.x-array `->` HTuple.long
Column coordinates of the starting points of the input lines.

`RowEndIn` (input_control)	line.end.y-array `->` HTuple.long
Row coordinates of the ending points of the input lines.

`ColEndIn` (input_control)	line.end.x-array `->` HTuple.long
Column coordinates of the ending points of the input lines.

`Feature` (input_control)	string(-array) `->` HTuple.char *
Features to be used for selection.
Default value: 'length'
List of values: 'length', 'row', 'column', 'phi'

`Operation` (input_control)	string `->` HTuple.char *
Desired combination of the features.
Default value: 'and'
List of values: 'and', 'or'

`Min` (input_control)	string(-array) `->` HTuple.char * / long / double
Lower limits of the features or 'min'.
Default value: 'min'

`Max` (input_control)	string(-array) `->` HTuple.char * / long / double
Upper limits of the features or 'max'.
Default value: 'max'

`RowBeginOut` (output_control)	line.begin.y-array `->` HTuple.long *
Row coordinates of the starting points of the output lines.

`ColBeginOut` (output_control)	line.begin.x-array `->` HTuple.long *
Column coordinates of the starting points of the output lines.

`RowEndOut` (output_control)	line.end.y-array `->` HTuple.long *
Row coordinates of the ending points of the output lines.

`ColEndOut` (output_control)	line.end.x-array `->` HTuple.long *
Column coordinates of the ending points of the output lines.

Result

The operator ::select_lines returns the value H_MSG_TRUE if the parameter values are correct. Otherwise an exception is raised.

Possible Predecessors

::sobel_amp, ::edges_image, ::threshold, ::hysteresis_threshold, ::split_skeleton_region, ::split_skeleton_lines

Possible Successors

::set_line_width, ::disp_line

Alternatives

::line_orientation, ::line_position, ::partition_lines

Module

Region processing