CENTRO (Feb93)                   gongcor                  CENTRO (Feb93)



NAME
    centro - Find the centroid of the solar image
    
    
USAGE
    centro input iopt thresh updhdr
    
    
PARAMETERS
    
    input
        List of input pixel arrays containing full disk  images  of  the
        sun.
        If N1 and N2 are the dimensions of the images,
        N1/2.LE.N2.LE.2*N1;  i.e.  the  dimensions must be approximately
        equal.
    
    iopt
        Select the strategy for determining the centroid.
            IOPT=0; use all data values
            IOPT=1; use all data values greater than THRESH
            IOPT=2; use all data values greater than THRESH,
                but weighted equally, rather than by their values.
    
    thresh
        Intensity threshold for options 1 and 2.
    
    updhdr
        If YES, the values of the  centroid  parameters  in  the  header
        will be updated after the parameters are determined.
    
    
IMAGE HEADER WORDS
    
    IF  UPDHDR=YES,  the  following  parameters are written to the input
    image header:
            CENTROXC, the x-coordinate of the centroid in pixels
            CENTROYC, the y-coordinate of the centroid in pixels
    
    IF UPDHDR=YES, the task writes the processing  parameters  into  the
    input header using 'gr_history' from 'grutil/'.
    
    
DESCRIPTION
    
    CENTRO is derived from CNTR and CENT2D in the HAO FTACH package.
    
    If  UPDHDR=YES,  the  x  and  y  pixel values of the location of the
    centroid are written to the image header.
    
    If the input image consists of more than 1 2d array of  pixels,  the
    2d  arrays are summed into 1 2d array before the centroid parameters
    are determined.
    
    
EXAMPLES
    
    
TIME REQUIREMENTS
    
    
BUGS
    
    
SEE ALSO
    fndlmb