Re: Displaying histogram in ImageJ with fixed limits

Posted by Rasband, Wayne (NIH/NIMH) [E] on Feb 21, 2010; 4:03am
URL: http://imagej.273.s1.nabble.com/Displaying-histogram-in-ImageJ-with-fixed-limits-tp3688303p3688307.html

On Feb 20, 2010, at 9:42 PM, V Byrd wrote:

> I am trying to view a 16 bit image with min intensity value of 0 and max
> intensity value of 32767.
> When the image is displayed the max values "look" white however, for a 16
> bit image it should be a shade of gray.
> As I move the cursor over the image the correct intensity value is displayed
> in the ImageJ window (that is x coordinate, y coordinate , value).
> If I adjust the brightness and contrast and manually set min = 0 and max
> = 32767 the display of the image is corrected so that the max intensity
> values look to be a shade of gray.  Although the display is changed, the
> histogram still shows min=0 and max = 32767. How do I get the histogram to
> display fixed limits (0 to 65535) for 16 bit image even though the image
> only contains two values zero and 32767?
>
> I am able to force it to show the entire range (0 to 65535) by strategically
> setting a single pixel value to 65535. When this is done the entire range is
> displayed automatically, but I would like for the entire range to be
> displayed in the histogram automatically without the need to tweak the image
> to do so.
>
> Does anyone know of a way to do this?

Run the Histogram command by pressing alt-h and ImageJ will display a dialog box that allows you to specify the range.

-wayne