3DOG

Section: User Commands (1)
Updated: November 25, 1990
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NAME

3dog - filter an image by applying a difference of Gaussians mask  

SYNOPSIS

3dog [-A esigma [masksize [ratio ]]] [-p #] [-b #] [-n #]

           [-s #] [-g #] [-i [-c]] [-m] [-lvf] [-w]

           [ < ] input > output  

DESCRIPTION

3dog filters an image by applying a difference of Gaussians mask. The input is in byte or float format of HIPS or FITS image type, and the output is in floating point or in integer format of HIPS image type.  

OPTIONS

-A
Esigma is the standard deviation of the ``excitatory'' Gaussian (default 1.0). (i.e. esigma gives the centeral peak feature).

Masksize is the size of the mask (an integer, defaults to 7).

Ratio is the ratio between the standard deviations of the inhibitory and excitatory Gaussians and defaults to 1.4. (when ratio = 1.0, the middle ring is flat. when ratio > 1.0, the middle ring is a valley. otherwise, middle is a slope from center top to side edge).

-p
followed by a positive integer specifies the precision and defaults to 1.
-b
begin process from #'th frame.
-n
the number of frames which will be processed
-i
implies output in integer format
-c
if -i is specified, causes checking of input to be in the range [-1024 to 1024].
-l
force 3dog to perform a level 2d filter (x-y, where `x' is an axis pointed toward the viewer, `y' is an axis from left to right, and `z' is a vertical axis.
-v
force 3dog to perform a vertical x-z 2d filter
-f
force dog3d to perform a vertical y-z 2d filter
-m
output the Gaussian(s) only, without convolving.
-g
normally the Gaussian output is a square image with sides which are a power of 2 just large enough to hold the Gaussian masks. The -g switch specifies the number of border pixels beyond the mask.
-s
span # - interpolate this number of frames between two neighboring slices (frames)
-w
output the pure image without header

If no input file is redirected, the program outputs an impulse response in a 7 x 7 x 7 frame.  

EXAMPLES

3dog -A .8 12 1.5 -b 4 -n 5 < bird > bird.dog3d
3dog -A1. 28 .8 < bird | scale_gray | histoeq | powertool -s "768 768" | xhips
After filtering, powertool spreads the 3d image to a large 2d surface (the -s switch).

3dog -A .6 53 1.6 -s7 bird | scale_gray | histoeq | slice -v 30 | xhips
After filtering, slice along x axis turned clockwise 30 degree about the center.  

SEE ALSO

dog2(1), multi_mask(n), mask(1), 3dmask(1), append(n), powertool(n), 3dslice(n)  

AUTHOR

Jin, Guojun 10/30/90


 

Index

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLES
SEE ALSO
AUTHOR

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