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Pamgauss User Manual(0) 						  Pamgauss User Manual(0)

NAME
       pamgauss - create a two dimensional gaussian function as a PAM image

SYNOPSIS
       pamgauss width height -sigma=number [-maxval=number] [-tupletype=string]

       Minimum	unique	abbreviation of option is acceptable.  You may use double hyphens instead
       of single hyphen to denote options.  You may use white space in place of the  equals  sign
       to separate an option name from its value.

EXAMPLES
	    pamgauss 3 3 -sigma=.5 -tupletype=GRAYSCALE | pamtopnm >gauss.pgm
	    pnmconvol -nooffset gauss.pgm myimage.ppm >blurred.ppm

DESCRIPTION
       This program is part of Netpbm(1)

       pamgauss  generates  a  one-plane PAM image whose samples are a gaussian function of their
       distance from the center of the image.  I.e.  the sample value is highest  in  the  center
       and goes down, in a bell curve shape, as you move away from the center.

       The values are scaled so that the volume under the surface of the two-dimensional Gaussian
       function is the maxval of the image.

       You can use this image as a convolution kernel with pnmconvol to  blur  an  image.   (This
       technique is known as Gaussian blurring).

       width  and height are the dimensions of the image that pamgauss generates.  Mathematically
       speaking, they are the domain of the two dimensional gaussian function.

       The sum of all the samples is equal to the image's maxval (within rounding  error).   This
       is true even if you clip the Gaussian function by making the image too small.  If you want
       to be sure you get a whole Gaussian function, make sure that you choose a sigma and  image
       dimensions  so  that  if  you  made it any larger, the sample values at the edges would be
       zero.

       The output image is PAM.  To make it usable with pnmconvol,  specify  -tupletype=GRAYSCALE
       so pnmconvol can use it as if it were PGM.  You must use the -nooffset option on pnmconvol
       because zero means zero in the PAM that pamgauss generates.

OPTIONS
       -sigma=number
	      This is the sigma parameter of the Gaussian function (if it were a Gaussian  proba-
	      bility function, this would be its standard deviation).  The higher the number, the
	      more spread out the function is.	Normally, you want to make this number low enough
	      that the function reaches zero value before the edge of your image.

	      number is in units of pixels.

	      This option is required.	There is no default.

       -maxval=number
	      This is the maxval for the output image.	It defaults to 255.

       -tupletype=string
	      This  is	the value of the "tuple_type" attribute of the created PAM image.  It can
	      be any string up to 255 characters.  If you don't specify this, pamgauss	generates
	      a PAM with unspecified tuple type.

SEE ALSO
       pnmconvol(1) , pamtopnm(1) , pgmkernel(1) , pamseq(1) , pam(1)

HISTORY
       pamgauss was new in Netpbm 10.23 (July 2004).

netpbm documentation			    8 May 2004			  Pamgauss User Manual(0)
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