pnmnoise
Generate random color noise images
TLDR
Create color noise image
$ pnmnoise [width] [height] > [noise.ppm]
Create with seed$ pnmnoise -randomseed [42] [256] [256] > [noise.ppm]
Grayscale noise$ pnmnoise [100] [100] | ppmtopgm > [noise.pgm]
SYNOPSIS
pnmnoise [options] width height
DESCRIPTION
pnmnoise generates a PNM image filled with random colored pixels. Each pixel has independently random red, green, and blue values, producing visual noise.
Similar to pgmnoise but produces color output.
PARAMETERS
width
Image width in pixels.height
Image height in pixels.-randomseed n
Seed for reproducibility.
EXAMPLES
$ # Color noise 512x512
pnmnoise 512 512 > noise.ppm
# Reproducible noise
pnmnoise -randomseed 12345 100 100 > noise.ppm
# Convert to PNG
pnmnoise 200 200 | pnmtopng > noise.png
# Grayscale version
pnmnoise 100 100 | ppmtopgm > gray_noise.pgm
pnmnoise 512 512 > noise.ppm
# Reproducible noise
pnmnoise -randomseed 12345 100 100 > noise.ppm
# Convert to PNG
pnmnoise 200 200 | pnmtopng > noise.png
# Grayscale version
pnmnoise 100 100 | ppmtopgm > gray_noise.pgm
CAVEATS
Produces full color noise (PPM format). For grayscale use pgmnoise. Random distribution is uniform.
HISTORY
pnmnoise is part of Netpbm by Jef Poskanzer and contributors for generating random images.