ppmtogif

Convert PPM images to GIF format

TLDR

Convert PPM to GIF

$ ppmtogif [input.ppm] > [output.gif]

With transparency

$ ppmtogif -transparent [color] [input.ppm] > [output.gif]

Interlaced GIF

$ ppmtogif -interlace [input.ppm] > [output.gif]

With alpha transparency from a PGM file

$ ppmtogif -alpha [mask.pgm] [input.ppm] > [output.gif]

ppmtogif converts PPM images to GIF format. GIF is limited to 256 colors, so use ppmquant first if needed.This program was superseded by pamtogif in Netpbm 10.37 (December 2006). New use of ppmtogif is discouraged; use pamtogif instead.Part of the Netpbm toolkit.

PARAMETERS

-transparent [=]color

Make the specified color transparent. If prefixed with =, only an exact match is used; otherwise the closest color in the image is selected.

-alpha pgmfile

Use a PGM file as an alpha (transparency) mask. White is opaque, black is transparent. Cannot be used with -transparent.

-interlace

Produce an interlaced GIF file.

-sort

Produce a GIF file with the colormap sorted in a predictable order.

-map mapfile

Use colors from the specified PPM file as the colormap instead of the colors in the input image.

-comment text

Include a comment in the GIF output.

-nolzw

Do not use LZW compression. Produces larger but unencumbered output.

EXAMPLES

$ # Basic conversion
ppmtogif image.ppm > image.gif

# With transparency (exact color match)
ppmtogif -transparent =white logo.ppm > logo.gif

# With alpha mask from a PGM file
ppmtogif -alpha mask.pgm image.ppm > transparent.gif

# Quantize first for photos with many colors
ppmquant 256 photo.ppm | ppmtogif > photo.gif

# Interlaced for web
ppmtogif -interlace image.ppm > interlaced.gif

# From JPEG
jpegtopnm photo.jpg | ppmquant 256 | ppmtogif > photo.gif

CAVEATS

GIF is limited to 256 colors. Use ppmquant to reduce colors before conversion. The -transparent and -alpha options cannot be used together. This command is deprecated in favor of pamtogif.

HISTORY

ppmtogif is part of Netpbm by Jef Poskanzer, with LZW compression code by various contributors.