cvtoppm

Section: Games and Demos (6)
Updated: November 1994
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NAME

cvtoppm - a program to generate depth maps and convert MindImage's rle files to pgm and ppm formats  

SYNTAX

cvtoppm [options] <input file> [output p*m file]  

DESCRIPTION

Cvtoppm is a utility with several functions. Primarily, it generates depth maps from 3D datasets such as those given in .polyh and .xss files. It is also capable of reading MindImage's rle format and rescaling old depth maps. All output is in one of the portable pixmap formats, chosen by the user.

The main purpose of this program is to allow those feeling artistic to create and amend a depth map with a paint package. The result can be viewed as a SIRDS or SIS using vpgs or sisgen.

The depth map output is either a grey-scale (.pgm) or colour (.ppm) image. Normally, the format used has an intensity value in the range 0-255 (for colour, three values are used in each pixel) this limits the depth resolution to 256 (or 16777216) levels. This limitation can be altered with a switch but the disadvantage is that the resultant file will be rather large. [Technically, when zmax is less than 256 the PBM raw formats are used instead of the ASCII formats.] Also unless the computer display you are using can cope with a lot more than 256 colours, editing the depth maps is fraught with difficulties. That is, you have to have at least 24bit colour to manipulate continuous colour images.

It takes at least one filename (or a switch to use stdin) and optional switches as its command line arguments.  

Options

All these options can be abbreviated to the least letters needed to make the chosen option distinct. The default values are given in parentheses.

-geometry <wxh>
sets the picture geometry, this defaults to the values given if the input is 3D data otherwise it defaults to the depth map size. (320x198)
-background <b>
sets the background plane at z=b*OY. (-1.0)
-enlarge <ef>
specifies the enlargement of z coordinate . (1.0)
-mag <mf>
sets the magnification of the scene, only applies to 3D data. (1.0)
-pmm <res>
sets the dots' resolution in units of pixels per millimetre. (4.0)
-zmax <zm>
sets the maximum value of each primary colour to be used in saving a .ppm file or the number of greys in a .pgm file. (255)
-colour
specifies that the output file will be a colour one.
-xss
signifies that the input file contains 3D data and is either an .xss or a .polyh file. This is the default.
-dmap
signifies that the input file contains a depth map and is a grey-scale or colour portable pixmap, .pgm or .ppm.
-mind
signifies that the input file contains a rle depth map generated by MindImage.
-zblines <zb>
sets the number of lines that each z-buffer will use, see xpgs(6). (256)
-output
turns on pipe mode to use stdout for resultant p?m file.
-help
prints a summary of command line options and returns to shell.

Once running, it will decide on the operations to perform solely on the command line switches.

 

FILES

 

BUGS

If you find any bugs, please report them to the author listed below.  

SEE ALSO

cvtopolyh(6), cvtoppm(6), mkpolyh(6), sisgen(6), vpgs(6), xpgs(6) and xss(6).  

AUTHOR, COPYRIGHTS, AND WARNINGS

Copyright 1994, 16th November.

By Peter Chang. All rights reserved.

peterc@v2.ph.man.ac.uk

Version 1.0

See notice in the xpgs man page.


 

Index

NAME
SYNTAX
DESCRIPTION
Options
FILES
BUGS
SEE ALSO
AUTHOR, COPYRIGHTS, AND WARNINGS

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