Hpcdtoppm User Manual

# hpcdtoppm

Updated: 26 May 2026
Table Of Contents

## NAME

hpcdtoppm - convert a Photo-CD image into a PBM image

## SYNOPSIS

hpcdtoppm infile [-a] [{-C|-0|-Overview|-O} file opt] [-c0] [-c-] [-c+] [-crop] [-d] [-dpi f] [-eps] [-epsd] [-epsg] [-fak scale] [-hori] [-i] [-l] [-m] [-n] [-pb pos] [-pgm] [-ph height] [-pl pos] [-pos] [-ppm] [-ps] [-psd] [-psg] [-pw width] [-r] [-rep] [-S long short] [-s] [-vert] [-x] [-ycc] [-1|-Base/16|-128x192] [-2|-Base/4|-256x384] [-3|-Base|-512x768] [-4|-4Base|-1024x1536] [-5|-16Base|-2048x3072] [-6|-64Base|-4096x6144] [outfile]

## DESCRIPTION

This program is part of Netpbm.

This program accepts Photo-CD image or overview file data from the specified input file, infile (or, if the resolution is lower than 64Base and the file argument is specified as -, from standard input), and writes either PBM Format or PostScript to the specified output file (or to standard output if no file is specified).

On a standard Photo-CD, image files appear in the directory photo_cd/images, in files with names of the form imgnnnn.pcd, where nnnn is a 4-digit-number. The overview file appears in photo_cd/overview.pcd.

Photo-CD images are stored using as many as 6 different resolutions:

              Format              Resolution
              ------              ----------
              64Base              4096x6144 (ProPhotoCD only)
              16Base              2048x3072
              4Base               1024x1536
              Base                512x768
              Base/4              256x384
              Base/16             128x192

The overview file employs Base/16 format.

## OPTIONS

Invoking hpcdtoppm without arguments produces a list of default values. Note that you can supply only one size option.

In addition to the options common to all programs based on libnetpbm (most notably -quiet, see Common Options), hpcdtoppm recognizes the following command line options:

-a
  Automatically determine image orientation (this option is experimental, and does not work for overview files).
{-C | -0 | -Overview | -O } file opt
  Extract all images from an overview file. The mandatory file argument is the name of a PPM file; output files are named filennnn, where nnnn is a 4-digit number. Overview images are extracted in their original Base/16 format. The value of opt determines the orientation of the contact sheet image; recognized values are:
  n
    Do not rotate the image.
  l
    Rotate the picture counter-clockwise (portrait mode).
  r
    Rotate the picture clockwise (portrait mode).
-c0
  Do not correct (brighten or darken) the image.
-c-
  Darken the image.
-c+
  Brighten the image.
-crop
  Cut off the black frame which sometimes appears at the image borders.
-d
  Show only the decompressed difference rather than the complete image (applicable only to 4Base and 16Base images).
-dpi res
  Set the printer resolution to res for dithered Postscript images.
-eps
  Write a RGB Encapsulated Postscript color image.
-epsd
  Write a Floyd-Steinberg dithered image in Encapsulated Postscript.
-epsg
  Write a grayscale image in Encapsulated Postscript.
-fak scale
  Set the scaling factor for dithered PostScript images to scale.
-hori
  Flip the image horizontally.
-i
  Send information from an image file header to Standard Error.
-l
  Rotate the picture counter-clockwise (portrait mode).
-m
  Write messages about the phases of decoding to standard error.
-n
  Do not rotate the image.
-pb pos
  Set the bottom position of the Postscript image to pos.
-pgm
  Write a pgm (grayscale) image.
-ph height
  Set the height of the Postscript image to height.
-pl pos
  Set the leftmost position of the Postscript image to pos.
-pos
  Print the relative starting position of the data for the current resolution.
-ppm
  Write a ppm RGB (color) image.
-ps
  Write a RGB Postscript color image.
-psd
  Write a Floyd-Steinberg dithered image in Postscript.
-psg
  Write a Postscript grayscale image.
-pw width
  Set the width of the Postscript image to width.
-r
  Rotate the picture clockwise (portrait mode).
-rep
  Try to jump over reading errors in the Huffman code.
-S long short
  Cut out a subrectangle with boundaries defined by the values:
  long
    For the longer side of the image.
  short
    For the shorter side of the image.
  where long and short take one of two forms:
  a-b
    Cut from position a to position b.
  a+b
    Starting at offset a, cut a length of b.
  and where a and b are either integers representing pixel locations, or floating point values over the range [0.0 ... 1.0], representing the fraction of the length of a side.
-s
  Apply a simple sharpness operator to the luminosity channel.
-vert
  Flip the image vertically.
-x
  Overskip Mode (applicable to Base/16, Base/4, Base and 4Base). In Photo-CD images the luminosity channel is stored in full resolution, the two chromaticity channels are stored in half resolution only and have to be interpolated. In Overskip Mode, the chromaticity channels of the next higher resolution are taken instead of interpolating. To see the difference, generate one PPM with and one PPM without this option. Use pamarith to generate the difference image of these two images. Call ppmhist for this difference or show it with xv (push the HistEq button in the color editor).
-ycc
  Write the image in a variation on PPM format in which the samples are YCC instead of RGB.
-1|-Base/16|-128x192
  Extract the Base/16 image.
-2|-Base/4|-256x384
  Extract the Base/4 image.
-3|-Base|-512x768
  Extract the Base image.
-4|-4Base|-1024x1536
  Extract the 4Base image.
-5|-16Base|-2048x3072
  Extract the 16Base image.
-6|-64Base|-4096x6144
  Extract the 64Base image. This resolution can be extracted from ProPhotoCD images only. The path of the 64Base extension files is derived from the path to the image file. This means that it doesn't work on stdin an the directory structure must be the very same as on the ProPhotoCD.

## POSTSCRIPT OUTPUT

For Postscript output (options -ps, -eps, -psg, -epsg, -psd, -epsg) you can define both the resolution and placement of the image. Both size and position are specified in points (1/72 inch).

The position of the image (where the origin is assumed to be at the lower left corner of the page) is controlled by the -pl and -pb options (applicable at all resolutions).

The size of color and grayscale images is changed with the -pw and -ph options. Every image pixel is mapped onto one Postscript pixel.

There are three modes of control for dithered Postscript:

Image size
  (-pw and -ph)
Printer resolution
  (-dpi)
Scaling factor
  (-fak)

These three factors are interdependent, hence no more then two can be specified simultaneously. Using -dpi and the -pw/-ph options together often yields pleasing results. Even using the default values for these options will produce results differing from those obtained without use of the options.

## LIMITATIONS

The program ignores read protection.

The -i option is not working correctly.

Available information obout the Photo-CD format is vague; this program was developed by trial-and-error after staring at hex-dumps. Please send bugs reports and patches to the author.

## AVAILABILITY

hpcdtoppm is not usually installed, because it is not licensed as freely as some people would like -- the copyright license is conditioned on not selling the code. Sourceforge does not allow distribution of such restricted code, so the Netpbm project packages this code separately, and given the almost nonexistent utility of this program, essentially nobody goes to the effort to install it.

## SEE ALSO

pcdovtoppm, pamarith, ppm, ppmhist, pnmquant, ppmtopgm, ppmtorgb3, xv

## VERSION

The name hpcdtoppm stands for "Hadmut's pcdtoppm," to make it distinguishable in the event that someone else is building a similar application and naming it pcdtoppm.

This is version 0.6.

## AUTHOR

Copyright (c) 1992, 1993, 1994 by Hadmut Danisch (danisch@ira.uka.de).

Hadmut Danish has given permission to Bryan Henderson (August 2003) to distribute this documentation as part of Netpbm on Sourceforge and therefore to license this copy of this documentation to the public with the following Sourceforge-compatible license. Note that this license does not contain a restriction on one's right to sell the material, as does the hpcdtoppm program itself and other copies of this documentation.

This software is not public domain. Permission to use and distribute this software and its documentation for noncommercial use and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation.

The hpcdtoppm software itself (as opposed to this supporting documentation) is licensed by Danisch under a similar license, but with an additional restriction that a recipient may not sell the software or use it in profit-making activity. See the source code of the program for details on its license.

Manual page extensively modified by R. P. C. Rodgers (rodgers@nlm.nih.gov).

## Table Of Contents

- SYNOPSIS
- DESCRIPTION
- OPTIONS
- POSTSCRIPT OUTPUT
- LIMITATIONS
- AVAILABILITY
- SEE ALSO
- VERSION
- AUTHOR