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vdist3d(1vi) [debian man page]

vdist3d(1Vi)															      vdist3d(1Vi)

NAME

       vdist3d - perform a 3D distance transform

SYNOPSIS

       vdist3d	[-option ...] [infile] [outfile]

DESCRIPTION

       vdist3d	performs a 3D distance transform on the source image to produce a file of a distance transformed destination image.  Each pixel in
       the output image contains the distance to the nearest feature element measured in a Euclidean or Chamfer metric.  If needed,  three  images
       containing the addresses of the nearest foreground pixels will also be produced.

       The input image must be of type VBit. The output image will be of type VFloat. If present, the vector images will be of type VShort.

       Input and output files can be specified on the command line or allowed to default to stdin and stdout.

       If  the	metric is euclidean, and no vectors are needed, the algorithm used is Saito/Toriwaki's algorithm.  If the metric is euclidean, but
       vectors are needed, then Daniellson's algorithm is used.  For the chamfer metric the algorithm by Borgefors is used.   Note  that  Daniell-
       son's  algorithm  is  the  most	expensive  (both  w.r.t  computing  time  as well as w.r.t space).  The second most expensive algorithm is
       Saito/Toriwaki's.  However, it is not possible to obtain the distance vectors from this algorithm.  The cheapest is Borgefors's, which also
       does not yield the distance vectors.

       Note  that  in  some rare cases, Daniellson's algorithm fails.  In that case, use Saito's algorithm (which always works) and do without the
       distance vectors.

LITERATURE

       Toyofumi Saito, Jun-Ichiro Toriwaki, New algorithms for euclidean distance transformation of a  n-dimensional  picture  with  applications,
       Pattern Recognition, Vol. 27, No. 11, pp 1551-1565, 1994.

       Gunilla Borgefors, "Distance Transformations in Arbitrary Dimensions", Computer Vision, Graphics and Image Processing, Vol 27, pp. 321-345,
       1984.

       P.-E. Daniellson, "Euclidean Distance Mapping", Computer Graphics and IMage Processing, Vol. 14, pp. 227-248, 1980.

COMMAND LINE OPTIONS

       vdist3d accepts the following options in any order:

       -help	      Causes vdist3d to print out a message describing its options.

       -metric euclidean/chamfer
		      Determines which metric to use.

       -vector yes/no Determines whether or not a vector image will be produced.  Default: no.

SEE ALSO

       Vista(7Vi)

AUTHOR

       Gabriele Lohmann <lohmann@cns.mpg.de>

Vista Version 2.1						  17 August 1994						      vdist3d(1Vi)

Check Out this Related Man Page

vselect(1Vi)															      vselect(1Vi)

NAME

       vselect - select objects from a Vista data file

SYNOPSIS

       vselect [-option ...] [infile] [outfile]

DESCRIPTION

       vselect copies selected objects from an input file to an output file.

       Command	line  options specify which objects are to be copied. Objects may be selected by type (e.g., all images), by name, by the value of
       some attribute, or by position within the input file.

COMMAND LINE OPTIONS

       vselect accepts the following options:

       -help	      Prints a message describing options.

       -in	      Specifies a Vista data file from which objects are to be selected.

       -out	      Specifies where to write the selected objects as a Vista data file.

       The input and output files can be specified on the command line or allowed to default to the standard input and output streams.

       In addition, exactly one of the following options must be used to specify the objects to be selected:

       -object i      Select the ith object. Objects in the input file are numbered consecutively from 0.

       -name name     Select any object whose attribute name is name.

       -type type     Select any object whose type is type.

       -attr name value
		      Select any object having an attribute with the specified name and value.

       Finally, any of these selection criteria can be inverted:

       -not	      Reverses the sense of the selection criterion.

EXAMPLES

       To select the first object from a file:

	      vselect -object 0 < infile > outfile

       To select the attribute named ``cantaloupe'' from a file:

	      vselect -name cantaloupe < infile > outfile

       To select everything but images from a file:

	      vselect -type image -not < infile > outfile

       To select images with ubyte pixels from a file of images:

	      vselect -attr nbands ubyte < infile > outfile

AUTHOR

       Art Pope <pope@cs.ubc.ca>

Vista Version 1.12						   24 April 1993						      vselect(1Vi)
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