netpbm

toolkit for image manipulation

TLDR

Convert JPEG to PPM

$ jpegtopnm [image.jpg] > [image.ppm]

Convert PNG to PPM

$ pngtopam [image.png] > [image.ppm]

Convert PPM to JPEG

$ pnmtojpeg [image.ppm] > [image.jpg]

Resize image

$ pamscale -width [800] [input.ppm] > [output.ppm]

Flip image

$ pamflip -lr [input.ppm] > [output.ppm]

SYNOPSIS

netpbm [tool] [options] [files]

netpbm is a toolkit of over 350 separate programs for manipulation of graphic images, including conversion between about 100 graphics formats. The programs use PNM (Portable Any Map) and PAM as intermediate formats for pipeline-based image processing.The tools are designed for command-line use and pipeline composition. A typical workflow converts an input format to PNM, applies transformations, then converts to an output format. Each tool does one thing, and they are most powerful when combined in shell pipelines.

COMMON TOOLS

jpegtopnm

Convert JPEG to PNM format.

pngtopam

Convert PNG to PAM format.

pnmtojpeg

Convert PNM to JPEG format.

pnmtopng

Convert PNM to PNG format.

ppmtogif

Convert PPM to GIF format.

giftopnm

Convert GIF to PNM format.

pamscale

Scale (resize) images.

pamflip

Flip or rotate images.

pnmcrop

Crop whitespace from edges.

ppmbrighten

Adjust brightness and saturation.

pnmcat

Concatenate images side by side or vertically.

CAVEATS

Not an interactive tool. Requires converting to/from PNM/PAM intermediate formats. Individual tools have separate man pages. Some tools have been superseded by newer equivalents (e.g., pnmtopng replaces ppmtogif for many use cases).

HISTORY

Netpbm evolved from PBMPLUS, a pioneering image manipulation package created by Jef Poskanzer in 1988.