>  Docs Center  >  Libraries  >  JHU/APL/S1R  >  XHISTPICK






      Widget routine to select image scaling based on a histogram.


Calling Sequence

      xhistpick, xx, hh


      xx = Histogram bin positions. in
      hh = Histogram counts. in

Keyword Parameters


        MIN=mn Returned selected lower image value cutoff.
        MAX=mx Returned selected upper image value cutoff.
          If defined these values will also be used as initial
          values of the cutoffs.
        TITLE=txt Title text string or array.
        ERROR=err Error flag: 0=OK, 1=CANCEL
        CLIP=n Clip max histogram count to the n'th below the
          highest count. Good for ignoring spikes in histogram.
          /clip may work well, or try clip=2 or 3.
        IMAGE=img Image to display (def=none). If given, this
          image will be displayed in the specified window with
          the currently selected scaling limits.
        WINDOW=win Window for image display (def=0). Only
          needed if an image is given.
        /ON_FREEZE redisplay image every time a limit is frozen
          in a new position. Else a Redisplay button appears.
        /WAIT means wait for returned result.
        GROUP_LEADER=grp specified group leader. When the
          group leader widget is destroyed this widget is also.
        Any valid PLOT keywords will be passed on to PLOT.


Common Blocks


      Notes: Histogram and bin position array may be made using
        hist. Ex: hh=hist(img,xx)
        Try xx(2:0),hh(2:*) to drop a large count of image zeros
        and the bottom added bin. See h=hist(/help)).
        Image may be floating.

Modification History

      R. Sterner, 7 Dec, 1993
      R. Sterner, 13 Dec, 1993 --- Added clip and _extra.
      R. Sterner, 2008 Oct 31 --- Made histogram display bigger.
  Copyright (C) 1993, Johns Hopkins University/Applied Physics Laboratory
  This software may be used, copied, or redistributed as long as it is not
  sold and this copyright notice is reproduced on each copy made. This
  routine is provided as is without any express or implied warranties
  whatsoever. Other limitations apply as described in the file disclaimer.txt.

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