HISTO

This program produces a listing and a plot of the number of occurences of optical densities within an array of any size.  The only input parameter are the starting and end points in x and y, respectively.  The type of plot (linear or logarithmic) can also be chosen.  To be able to view the listing of the densities a logfile should be created rather than running the program online.  An error message “number of out-of-bounds plot errors ....” may appear in the logfile.  This message is erroneous and can be ignored.  The listing of the optical densities is useful to determine cut-off values if the image is to be pruned to eliminate outliers due to dust or scratches on the negative.