RETRO (vipl) functions


LIBRARY ROUTINE

lvclose - Close boundaries on an image

LIBRARY CALL

int lvclose(
	unsigned char *edge,
	unsigned char *gradient,
	int nc,
	int nr,
	int length,
	int thresh)

INPUT

OUTPUT

RETURN VALUE

TRUE (1) on success, FALSE (0) on failure

DESCRIPTION

lvclose uses a boundary image and a gradient image as input. Then it tries to close the boundaries by following the maximum gradient between two end points of two contours. Both have to be pointers on xvimage data of VFF_TYP_1_BYTE data storage type.

The new closing part of a boundary is kept if its length is at least "Minimum_Gap_Size" pixels. This parameter is used to prevent the result from being covered by small contours (edges of noisy areas...).

The minimum gradient value "Gradient_Threshold" has to be set up to indicate to the the closing process up to what value it can follow a maximum gradient curve to close a boundary.

This Algorithm has been writen by: Professor SERGE CASTAN, Prof CHEN and Dr ZHAO, IRIT, CNRS, URA 1399, 118, route de Narbonne 31062 Toulouse FRANCE

ADDITIONAL INFORMATION

none

EXAMPLES

none

SIDE EFFECTS

none

RESTRICTIONS

lvclose will only work with VFF_TYP_1_BYTE images.

MODIFICATION

Fixed indexing bug in function max_grdt() so that no negative indexes, same problem rechercher_candidats(). John Rasure Fri Feb 28 19:46:13 MST 1992

FILES

$RETRO/objects/library/vipl/src/lvclose.c

SEE ALSO

vipl(3)

COPYRIGHT

Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.