pgmnoise

create a PGM image filled with random grayscale pixels

TLDR

Create a 100x100 white noise image

$ pgmnoise [100] [100] > [noise.pgm]

Create a full HD noise image

$ pgmnoise [1920] [1080] > [noise.pgm]

Create noise and convert to PNG

$ pgmnoise [256] [256] | pnmtopng > [noise.png]

Create reproducible noise with a fixed seed

$ pgmnoise -randomseed [12345] [100] [100] > [noise.pgm]

Create a small noise tile and repeat it

$ pgmnoise [64] [64] | pnmtile [256] [256] > [texture.pgm]

SYNOPSIS

pgmnoise [options] width height

pgmnoise creates a portable graymap (PGM) image where each pixel is independently assigned a uniformly distributed random gray value between 0 and the maximum value. The output is written to standard output in PGM format.The tool is useful for testing image processing pipelines, creating noise textures, or generating random patterns that can be piped into other Netpbm tools.

PARAMETERS

width

Image width in pixels.

height

Image height in pixels.

-randomseed n

Seed for the random number generator, allowing reproducible output.

-maxval n

Maximum gray value for pixels. Defaults to the PGM compile-time maximum (typically 255 or 65535).

CAVEATS

Uses uniform random distribution only. For Gaussian or other noise types, use pamaddnoise or combine with other tools. Output goes to stdout and must be redirected. Part of the Netpbm toolkit.

HISTORY

pgmnoise is part of Netpbm, the graphics toolkit originally created by Jef Poskanzer in the late 1980s and maintained by Bryan Henderson since 2000.