DOKK / manpages / debian 11 / netpbm / pnmindex.1.en
pnmindex(1) General Commands Manual pnmindex(1)

pnmindex - build a visual index of a bunch of anymaps

pnmindex [-size N] [-across N] [-colors N] [-black] [-title T] [-quant|-noquant] pnmfile ...

pnmindex creates an index image containing thumbnail (small) versions of a bunch of PNM files you supply.

pnmindex labels each thumbnail and, optionally, contains a title.

The size of each thumbnail. The image is scaled to fit maximally inside a N x N pixel box without changing its aspect ratio. Default is 100.
The number of thumbnails in each row. Default is 6.
The maximum number of colors allowed in the overall image. If it would otherwise have more colors than these, pnmindex quantizes the result. The default is 256.

However, this value is meaningless if you specify the -noquant option.

This controls the color of the padding between the images; normally it's white and the labels are black lettering on white background, but the -black flag reverses this.
Specifies a title top place at the top of the image. Default is no title.
Enables quanization (to the number of colors specified by -colors ). Quantization is on by default but you can disable it with -noquant.
See -quant.

pnmscale(1), pnmcat(1), pbmtext(1), ppmquant(1), pnm(5)

Copyright (C) 1991 by Jef Poskanzer. -title and -noquant added 2000 by John Heidemann.

9 January 1991