pcontourextensionconic

Performs cone-shaped extension of end points.

Synopsis

pcontourextensionconic length [-m mask] [im_in|-] [im_out|-]

Description

pcontourextensionconic extends all contour end points by a cone shape defined by the size length. A contour chain is a sequence of connected non null pixels with 1 pixel thickness. An end point is a contour point with only 1 neighbor.

The extension of the end point is done with a cone of the specified length in the sense of the contour. For example, the 2D contour on the left is extended to the contour on the right if length=3.

                        x
                       xx
                      xxx
    xxxx    ->   xxxxxxxx
                      xxx
                       xx
                        x

Warning: if the contour is not 1 pixel thickness, the operator may have unpredictable behavior. It might be necessary to use the operator ppostthinning to guaranty 1 pixel thickness.

Parameters

length is an integer that specifies the length of the cone in the sense of the contour.

Inputs

im_in: a 2D or 3D grayscale image (Img2duc or Img3duc).

Outputs

im_out: an image of the same type as the input image.

Result

The number of end points.

Examples

Closes contours yielded by a simple edge detection of tangram.pan by using an extension of the end points:

   psobel tangram.pan b.pan
   pbinarization 55 1e30 b.pan c.pan
   pskeletonization c.pan d.pan 
   ppostthinning d.pan e.pan
   pcontourextensionconic 3 e.pan f.pan
   plabeling 8 f.pan out.pan

C++ prototype

Errc PContourExtensionConic( const Img2duc &im_in, Img2duc &im_out, int length );

Version française

Extension des points terminaux dans la direction du contour par une forme conique.

Author: Arnaud Renouf