line_orientation ( : : RowBegin, ColBegin, RowEnd, ColEnd : Phi )

Calculate the orientation of lines.

The operator line_orientation returns the orientation (-2 < Phi <= pi/2) of the given lines. If more than one line is to be treated the line and column indices can be passed as tuples. In this case Phi is, of course, also a tuple and contains the corresponding orientations.

The procedure is typically applied to model lines in order to select parallel image lines, which were found, e.g., by detect_edges1, via the operator select_lines1.


Parameters

RowBegin (input_control)
line.begin.y(-array) -> integer
Row coordinates of the starting points of the input lines.

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

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

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

Phi (output_control)
angle.rad(-array) -> real
Orientation of the input lines.


Result

line_orientation always returns the value TRUE.


Possible Predecessors

sobel_amp, edges__, threshold__, hysteresis_threshold__, split_skeleton1, split_skeleton2


Possible Successors

set_line_width, disp_line


Alternatives

line_position, select_lines1, select_lines2


See also

line_position, select_lines1, select_lines2, detect_edges1



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