---
name: "hdifftopam"
section: "1"
platform: "linux"
package: "netpbm"
version: "10.86.51-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/hdifftopam"
---

# hdifftopam(1)

convert horizontal difference image to original PAM image

## NAME

hdifftopam - convert horizontal difference image to original PAM image

## SYNOPSIS

**hdifftopam**\[*pamfile*\] \[**-pnm**\] \[**-verbose**\]

Minimum unique abbreviation of option is acceptable.  You may use double hyphens instead of single hyphen to denote options.  You may use white space in place of the equals sign to separate an option name from its value.

## DESCRIPTION

This program is part of **Netpbm**(1) .

**hdifftopam** undoes what **pamtohdiff** does.

## OPTIONS

In addition to the options common to all programs based on libnetpbm (most notably **-quiet**, see \
  Common Options ⟨index.html#commonoptions⟩ ), **hdifftopam** recognizes the following command line options:

- **-pnm**

       This option tells **hdifftopam** to create a PNM image (i.e. PGM or\
        PPM).  Without it, **hdifftopam** creates a PAM image (with a\
        tuple type of "unhdiff").  If the PAM does not have the proper depth\
        to be a PGM or PPM (i.e. 1 or 3) and you specify **-pnm**,\
        **hdifftopam** fails.

- **-verbose**

       Print output image width, height, depth and maxval to standard error.

## SEE ALSO

[**pamtohdiff**(1)](/pamtohdiff/1.md)

## AUTHOR

Bryan Henderson

## DOCUMENT SOURCE

This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The master documentation is at

-

  **http://netpbm.sourceforge.net/doc/hdifftopam.html**