pgmkernel(1) General Commands Manual pgmkernel(1)NAME
pgmkernel - generate a convolution kernel
SYNOPSIS
pgmkernel [ -weight w ] width [ height ]
DESCRIPTION
Generates a portable graymap array of size width x height (or width x width if height is not specified) to be used as a convolution file by
pnmconvol. The data in the convolution array K are computed according to the formula:
K(i,j) = 1 / ( 1 + w * sqrt((i-width/2)^2 + (j-height/2)^2))
where w is a coefficient specified via the -weight flag, and width and height are the X and Y filter sizes.
The output PGM file is always written out in ASCII format.
OPTIONS
The optional -weight flag should be a real number greater than -1. The default value is 6.0.
BUGS
The computation time is proportional to width * height. This increases rapidly with the increase of the kernel size. A better approach
could be using a FFT in these cases.
SEE ALSO pnmconvol(1), pnmsmooth(1)AUTHOR
Alberto Accomazzi (alberto@cfa.harvard.edu).
10 December 1992 pgmkernel(1)
Check Out this Related Man Page
pnmsmooth(1) General Commands Manual pnmsmooth(1)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 option does not invoke pnmconvol.
SEE ALSO pnmconvol(1), pnm(5)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)
in terms of bits, what is the width of a User ID? seems like I remember it being 32-bit (maybe wrong) but I can't find anything anywhere on ther subject. (4 Replies)
Hi I have got one file FTPd from mainframe in an ASCII format in Unix environment.
If I have to deduce record width within this file, each approach we are finding different record width.
head -1 filename | wc -m
awk '{print length($0)}' filename ... lists record width for all records.
sed... (5 Replies)
My file has varied width references:
width=10%
style=width:5%
width:1506%
width:99.58%
so I'm trying clear all the width calls with one procedure:
's/width= *%//' and 's/width=*%//'but neither is working. (6 Replies)
Dear members..
I have a fixed width file. Requirement is as below:-
1. Scan each record from this fixed width file
2. Check for value under field no "6" equals to "ABC". If yes, then filter this record into the output file
Please suggest a unix command to achieve this, my guess awk might... (6 Replies)
I was reading Advanced Programming in the Unix Environment and it says to use ioctl() to get the terminal's width and height. I wrote this program:
// print width and height
#include <stdio.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <termios.h>
int main( int argc, char... (3 Replies)