NAME

centroid - determine the centroid and width of an object

SYNOPSIS

centroid file [box=] [sky=] [radius=] [debug..]

DESCRIPTION

This routine computes the location of the object by calculating the centroid to the image. The sky value may be entered in the command line to have the bias values removed before the moments are calculated.

Note: sort of a "modified" centroid is used in that negative values are not used in the centroid calculation. The are not removed for the total signal.

OPTIONS

box= limits the region over which the calculation applies. See discussion box specification.

sky= subtracts specified bias level before performing calculation. The default value is 0.

radius= changes the mode of the program. It now accepts input from stars and then calculates the centroids around the row,col using a box that is 2*radius on a side. The back from the stars is subrtracted off before centroiding. Stars whose box extends outside the image are skipped without comment.

EXAMPLE

centroid lyr.fits - finds the centroid of the object in file lyr.fits

centroid alflyr.fits box=100,150,20,25,1 sky=45
finds the centroid of the object in box with center row 100, center column 150 and 20 pixels high and 25 wide of the file alflyr.fits, using a sky value of 45.
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