# phpman > info > pnmsmooth

[pnmsmooth(1)](https://www.chedong.com/phpMan.php/man/pnmsmooth/1/markdown)                General Commands Manual               [pnmsmooth(1)](https://www.chedong.com/phpMan.php/man/pnmsmooth/1/markdown)

NAME
       pnmsmooth - smooth out an image

SYNOPSIS
       pnmsmooth [-size width height] [-dump dumpfile] [pnmfile]

DESCRIPTION
       Smooths  out  an  image by replacing each pixel with the average of its
       width X height neighbors.  It is implemented as a C progam that  gener-
       ates a PGM convolution matrix and then invokes pnmconvol.

OPTIONS
       -size width height
              Specifies the size of the convolution matrix.  Default size is a
              3x3 matrix.  Width and height sizes must be odd.   Maximum  size
              of  convolution  matrix  is  limited  by the maximum value for a
              pixel such that (width * height * 2) must not exceed the maximum
              pixel value.

       -dump dumpfile
              Generates  and saves the convolution file only.  Use of this op-
              tion does not invoke pnmconvol.

SEE ALSO
       [pnmconvol(1)](https://www.chedong.com/phpMan.php/man/pnmconvol/1/markdown), [pnm(5)](https://www.chedong.com/phpMan.php/man/pnm/5/markdown)

AUTHORS
       Copyright (C) 1989, 1991 by Jef Poskanzer.
       Converted from  script  to  C  program  December  1994  by  Mike  Burns
       (<burns@chem.psu.edu>).

                                4 December 1994                   [pnmsmooth(1)](https://www.chedong.com/phpMan.php/man/pnmsmooth/1/markdown)