pbmpscale(1) [minix man page]

pbmpscale(1)                                                  General Commands Manual                                                 pbmpscale(1)

NAME

       pbmpscale - enlarge a portable bitmap with edge smoothing

SYNOPSIS

       pbmpscale N [ pbmfile ]

DESCRIPTION

       Reads a portable bitmap as input, and outputs a portable bitmap enlarged N times. Enlargement is done by pixel replication, with some addi-
       tional smoothing of corners and edges.

SEE ALSO

       pnmenlarge(1), ppmscale(1), pbm(5)

AUTHOR

       Copyright (C) 1990 by Angus Duggan Copyright (C) 1989 by Jef Poskanzer.

       Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, pro-
       vided  that  the  above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in sup-
       porting documentation.  This software is provided "as is" without express or implied warranty.

NOTES

       pbmpscale works best for enlargements of 2. Enlargements greater than 2 should be done by as many enlargements of 2 as  possible,  followed
       by an enlargement by the remaining factor.

                                                                    12 Dec 1990                                                       pbmpscale(1)

pbmtopgm(1)						      General Commands Manual						       pbmtopgm(1)

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.

SEE ALSO

       netpbm(1), pgmtopbm(1), pbm(5)

AUTHOR

       Copyright (C) 1990 by Angus Duggan Copyright (C) 1989 by Jef Poskanzer.

       Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, pro-
       vided  that  the  above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in sup-
       porting documentation.  This software is provided "as is" without express or implied warranty.

								    03 Sep 2001 						       pbmtopgm(1)