RETRO commands


PROGRAM NAME

vclose - Close Boundaries of an Edge Image (K1)

DESCRIPTION

vclose 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.

The new closing part 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 closing process up to what value it can follow a maximum gradient curve to close a boundary.

This Algorithm has been written by:

Professor SERGE CASTAN, Prof CHEN and Dr ZHAO

IRIT, CNRS, URA 1399

118, route de Narbonne 31062 Toulouse FRANCE

REQUIRED ARGUMENTS

-i1
type: infile
desc: Input Boundary Image (result from vdrf, vgef, vsdef ...)
-i2
type: infile
desc: Input Gradient Image (result from vdrf, vsdef, sobel...)
-o
type: outfile
desc: resulting output image or file

OPTIONAL ARGUMENTS

-grad
type: integer
desc: Gradient Threshold (used by the closing process)
default: 0
bounds: value >= 0
-len
type: integer
desc: Minimum Gap Size In Pixels
default: 1
bounds: value >= 0

EXAMPLES

vclose -i1 moon_edge.xv -i2 moon_grad.xv -v 5 -f 0.5 -o closed_boundary.xv

Will use moon_edge.xv and moon_grad.xv as the edges and respectively the gradient representation of an image. Then it will close the unclosed boundaries using a minimum gap size of 5 pixels and a gradient threshold of 0.5

SEE ALSO

RESTRICTIONS

vclose will only work with single band images. Then the first image has to be of data storage type VFF_TYP_1_BYTE. The second input can be anything from VFF_TYP_1_BYTE to VFF_TYP_FLOAT.

REFERENCES

COPYRIGHT

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