select_lines

select_lines ( : : RowBeginIn, ColBeginIn, RowEndIn, ColEndIn, Feature, Operation, Min, Max : RowBeginOut, ColBeginOut, RowEndOut, 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 `->` integer
Row coordinates of the starting points of the input lines.

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

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

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

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

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

`Min` (input_control)	string(-array) `->` string / integer / real
Lower limits of the features or 'min'.
Default value: 'min'

`Max` (input_control)	string(-array) `->` string / integer / real
Upper limits of the features or 'max'.
Default value: 'max'

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

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

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

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

Result

The operator select_lines returns the value 2 (H_MSG_TRUE) if the parameter values are correct. Otherwise an exception is raised.

Parallelization Information

select_lines is reentrant and processed without parallelization.

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