.ds Vn 1.12
.TH vtopgm 1Vi "24 April 1993" "Vista Version \*(Vn"
.SH NAME
vtopgm \- convert image from Vista data file to portable graymap
.SH SYNOPSIS
\fBvtopgm\fR [\fB-\fIoption\fR ...] [\fIinfile\fR] [\fIoutfile\fR]
.SH DESCRIPTION
\fBvtopgm\fP converts one band of an image to a portable graymap (PGM) 
file. A wide range of filters are available to convert PGM files to other 
formats. 
.PP
This program only produces portable graymaps whose pixel values are in the 
range 0 to 255. Any type of Vista image is accepted, but the image is first 
converted to have \fBubyte\fP pixels if necessary. This conversion is 
performed by \fBVConvertImageRange\fP(3Vi). 
.SH "COMMAND LINE OPTIONS"
\fBvtopgm\fP accepts the following options:
.IP \fB-help\fP 15n
Prints a message describing options.
.IP "\fB-in\fP \fIinfile\fP
Specifies a Vista data file containing the image to be converted. If the 
file contains more than one image, only the first is used.
.IP "\fB-out\fP \fIoutfile\fP"
Specifies the file to contain the portable graymap.
.IP "\fB-band\fP \fIband\fP"
Specifies the image band to be converted. Default: 0.
.PP
Input and output files can be specified on the command line or allowed to
default to the standard input and output streams.
.SH "SEE ALSO"
.BR pgm (5),
.BR VImage (3Vi),
.BR Vista (7Vi)
.SH AUTHOR
David Lowe <lowe@cs.ubc.ca>