This is the command pbmtopgm that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
NAME
pbmtopgm - convert portable bitmap to portable graymap by averaging areas
SYNOPSIS
pbmtopgm width height [pbmfile]
DESCRIPTION
pbmtopgm reads a portable bitmap as input. It outputs a portable graymap in which each
pixel's gray level is the average the surrounding black and white input pixels. The
surrounding area is a rectangle of width by height pixels.
In other words, this is a convolution. pbmtopgm is similar to a special case of
pnmconvol.
You may need a ppmsmooth step after pbmtopgm.
pbmtopgm has the effect of anti-aliasing bitmaps which contain distinct line features.
pbmtopgm works best with odd sample width and heights.
You don't need pbmtopgm just to use a PGM program on a PBM image. Any PGM program
(assuming it uses the Netpbm libraries to read the PGM input) takes PBM input as if it
were PGM, with only the mininum and maximum gray levels. So unless your convolution
rectangle is bigger than one pixel, you're not gaining anything with a pbmtopgm step.
Use pbmtopgm online using onworks.net services
