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

# ppmshift(1)

shift lines of a PPM image left or right by a random amount

## NAME

ppmshift - shift lines of a PPM image left or right by a random amount

## SYNOPSIS

**ppmshift** *shift* \[*ppmfile*\]

## DESCRIPTION

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

**ppmshift** reads a PPM image as input.  It shifts every row of image data to the left or right by a random amount, within a range of *shift* pixels.  The random distribution is uniform, centered at zero movement.

The randomness in the image is limited before Netpbm 10.37 (December 2006) -- if you run the program twice in the same second, you may get identical output.

This is an effect the author intended to use for MPEG tests. Unfortunately, this program is not useful for that - it creates too random patterns to be used for animations.  Still, it might give interesting results on still images.

## OPTIONS

There are no command line options defined specifically for **ppmshift**, but it recognizes the options common to all programs based on libnetpbm (See \
  Common Options ⟨index.html#commonoptions⟩ .)

## EXAMPLE

Check this out: Save your favorite model's picture from something like alt.binaries.pictures.supermodels (ok, or from any other picture source), convert it to ppm, and process it e.g. like this, assuming the picture is  800x600 pixels:

```
     #take the upper half, and leave it like it is
     pamcut -top=0 -width=800 -height=300 cs.ppm >upper.ppm
     #take the lower half, flip it upside down, dim it and distort it a little
     pamcut -top=300 -width=800 -height=300 cs.ppm | \
         pamflip -topbottom | \
         ppmdim 0.7 | \
         ppmshift 10 >lower.ppm
     #and concatenate the two pieces
     pamcat -topbottom upper.ppm lower.ppm >newpic.ppm
```

The resulting picture looks like the image being reflected on a water  surface with slight ripples.

## SEE ALSO

**ppm**(1) , [**pamcut**(1)](/pamcut/1.md) , [**pamflip**(1)](/pamflip/1.md) , [**ppmdim**(1)](/ppmdim/1.md) , [**pamcat**(1)](/pamcat/1.md)

## AUTHOR

Copyright (C) 1993 by Frank Neumann

## 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/ppmshift.html**