Content-type: text/html Manpage of smooth

smooth

Section: User Commands (1)
Index Return to Main Contents
 

NAME

smooth - Convolve an image (in the image domain) with a 2-D gaussian  

PERSON RESPONSIBLE

nebk  

CATEGORIES

analysis  

DESCRIPTION

SMOOTH is a MIRIAD task which convolves an image by an elliptical gaussian or a boxcar the hard way. The convolving Gaussian and boxcar have peaks of unity. Additional scaling is provided by the keyword "scale"

By default, SMOOTH will mask pixels in the output image if there are more masked pixels than unmaked pixels in the Gaussian convolution area. This means that pixels which were maked in the input may be unmasked in the output.

See also CONVOL for the fft based method that is generally faster. HANNING is a program that only smoothes along the velocity axis.  

PARAMETERS

in
The input image. Wild card expansion is supported, no default.
out
The output image. No default.
type
Specifies the type of function to convolve by. Should be one of
  "gaussian"     Gaussian at arbitrary position angle 
  "boxcar"       Boxcar oriented in x and y directions. Note
                 that the full width is rounded up to be an 
                 odd number of pixels.
Default is gaussian. Minimum match is active.
fwhm
The Gaussian FWHM along the major and minor axes or the boxcar full widths in the x and y directions (all in arcseconds). The image pixel increments are assumed to be in radians. No default.
pa
The position angle in degrees CCW from North of the major axis of the gaussian. Not used for boxcar smoothing. Default is 0.0.
scale
If unset, then SMOOTH will attempt to make the units of the smoothed image be Jy/beam for Gaussian convolution. If 0.0, then the convolution integral is scaled (multipled) by the inverse of the volume of the convolving function. Otherwise, the integral is scaled by "scale"
options
"nocheck" By default, blanked input pixels do not contribute to the
   convolution sum.  If you set NOCHECK then blanked input pixels 
   are not checked for (but the output image is blanked around the 
   unconvolved edge, and wherever the input image is blanked).
"force" Force masking of pixels in the output image which
   are masked in the input image.


 

Index

NAME
PERSON RESPONSIBLE
CATEGORIES
DESCRIPTION
PARAMETERS

This document was created by man2html, using the manual pages.
Time: 18:35:38 GMT, July 05, 2011