vpolygon(1)

PROGRAM
vpolygon - Creates a vector image resulting from a polygonal approximation of an edge image.

SYNTAX

vpolygon

-i  Edge Image

-o1 Vector Image Resulting from the Polygonal Approximation

[-o2]
    Output Image Containing the Polygonal Edge Approximation

[-l]
    Minimal Length For Segment Extraction

[-p]
    Percentage of Segment Rejected

[-t]
    Threshold Value for the Approximation

[-V]
    Gives the version for vpolygon

[-U]
    Gives the usage for vpolygon

[-P]
    Prompts for command line options

[-A [file1]]
    Creates the answer file called vpolygon.ans or file1

[-a [file1]]
    Uses vpolygon.ans or file1 as the answer file

DESCRIPTION
vpolygon will create a vector image resulting of a polygonal approximation. The optional 2D image output can be used to display this approximation with a displaying function (putimage). The size of the optional image is equal to the size of the input image dimension, and it's a byte image with line points set to 255.

There are some optional inputs to control the approximation process :

[-l] : Minimal length for straight line extraction. When the estimated straigth line have a length less important than this threshold, it is skipped over.

[-p] : Percentage of line length rejected to calculate parameters of the straight line.

[-t] : Threshold Value for the approximation error. When the calculated error is greater than this value, the line is broken.

The program creates a vector image to store the result of the linear approximation. This image is a four bands image containing two points for each estimated line : (x1,y1) and (x2,y2) or one band per coordinate (first band for x1 coordinates, second band for y1 coordinates, third band for x2 coordinates and fourth band for y2 coordinates).

REQUIRED ARGUMENTS

-i  type: infile
    desc: Edge Image

-o1 type: outfile
    desc: Vector Image Resulting from the Polygonal Approximation

OPTIONAL ARGUMENTS

-o2 type: outfile
    desc: Output Image Containing the Polygonal Edge Approximation

-l  type: integer
    desc: Minimal Length For Segment Extraction
    default: 10
    bounds: value > 0

-p  type: float
    desc: Percentage of Segment Rejected
    default: 0.1
    bounds: 0.000000 < [-p] < 1.000000

-t  type: float
    desc: Threshold Value for the Approximation
    default: 0.6
    bounds: value > 0.0

EXAMPLES
vpolygon -i edge.xv -o1 vector.xv -o2 segment_image.xv

will create a vector image "vector.xv" resulting of the linear approximation on input image "edge.xv". We can display this result by using "segment_image.xv".

SEE ALSO
intro(1), verror(3), vgparms(3), vutils(3), lvpolygon(3)

RESTRICTIONS
vpolygon will operate on BYTE data storage type and with edge points set to 255.

COPYRIGHT
Copyright 1992, University of New Mexico. All rights reserved.