read_polygon_xld_arc

Herror ::read_polygon_xld_arc_info ( Hobject *Polygons, const HTuple &FileName ) HXLDPoly HXLDPoly::ReadPolygonXldArcInfo ( const HTuple &FileName ) HXLDPolyArray HXLDPolyArray::ReadPolygonXldArcInfo ( const HTuple &FileName )

Read XLD polygons from a file in ARC/INFO generate format.

::read_polygon_xld_arc_info reads the lines stored in ARC/INFO generate format in the file FileName, and returns them as XLD polygons in Polygons. To find the file FileName, all directories contained in the HALCON system variable 'image_dir' (usually this is the content of the environment variable HALCONIMAGES) are searched (see ::read_image). The returned polygons are in world coordinates. They can be transformed to the image coordinate system with the operator ::affine_trans_polygon_xld. The necessary transformation matrix can be generated by using ::read_world_file to read the transformation matrix from image to world coordinates, and inverting this matrix by calling ::hom_mat2d_invert.

Parameters

`Polygons` (output_object)	xld_poly(-array) `->` Hobject : HXLDPoly(Array)*
Read XLD polygons.

`FileName` (input_control)	filename `->` HTuple.char *
Name of the ARC/INFO file.

Example

/* Read the transformation and invert it */
read_world_file ('image.tfw', WorldTransformation)
hom_mat2d_invert (WorldTransformation, ImageTransformation)
/* Read the image */
read_image (Image, 'image.tif')
/* Read the line data */
read_polygon_xld_arc_info (LinesWorld, 'lines.gen')
/* Transform the line data to image coordinates */
affine_trans_polygon_xld (LinesWorld, Lines, ImageTransformation)

Result

If the parameters are correct and the file could be read, the operator ::read_polygon_xld_arc_info returns the value H_MSG_TRUE. Otherwise an exception is raised.

Possible Successors

::hom_mat2d_invert, ::affine_trans_polygon_xld

Module

Sub-pixel operators