pbmclean(1) - man - phpman

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⚡ TLDR: pbmclean (tldr-pages)

Clean up a PBM image by erasing isolated black and white pixels.

Clean up a PBM image by erasing isolated black and white pixels
pbmclean {{path/to/image.pbm}} > {{path/to/output.pbm}}
Clean up only black/white pixels
pbmclean -{{black|white}} {{path/to/image.pbm}} > {{path/to/output.pbm}}
Specify the minimum number of neighbouring pixels of the same color in order for a pixel not to be considered isolated
pbmclean {{-m|-minneighbours}} {{3}} {{path/to/image.pbm}} > {{path/to/output.pbm}}

pbmclean(1) General Commands Manual pbmclean(1)

NAME
pbmclean - flip isolated pixels in portable bitmap

SYNOPSIS
pbmclean [-minneighbors=N] [-black|-white] [pbmfile]

You can use the minimum unique abbreviation of the options. You can use two hyphens instead
of one. You can separate an option name from its value with white space instead of an equals
sign.

Before December 2001, pbmclean accepted -N instead of -minneighbors.

DESCRIPTION
pbmclean cleans up a PBM image of random specs. It reads a PBM image as input and outputs a
PBM that is the same as the input except with every pixel which has less than N identical
neighbours inverted.

The default for N is 1 - only completely isolated pixels are flipped.

(A value of N greater than 8 generates a completely inverted image (but use pnminvert to do
that) -- or a completely white or completely black image with the -black or -white option).

pbmclean considers the area beyond the edges of the image to be white. (This matters when
you consider pixels right on the edge of the image).

You can use pbmclean to clean up "snow" on bitmap images.

OPTIONS
-black

-white Flip pixels of the specified color. By default, if you specify neither -black nor
-white, pbmclean flips both black and white pixels which do not have sufficient iden‐
tical neighbors. If you specify -black, pbmclean leaves the white pixels alone and
just erases isolated black pixels. Vice versa for -white. You may specify both
-black and -white to get the same as the default behavior.