Re: calibration bar maximum value incorrect?

Posted by Rasband, Wayne (NIH/NIMH) [E] on Jun 05, 2014; 11:29pm
URL: http://imagej.273.s1.nabble.com/calibration-bar-maximum-value-incorrect-tp5008048p5008054.html

On Jun 5, 2014, at 6:54 PM, Neil Fazel wrote:

> Hi Wayne,
>
>   Thanks for the tip. I hadn't used Process -> Enhance Contrast... to normalize. But I just tried that, and the calibration bar range is correct if I do it that way.
>
> I had done it by first using Analyze -> Measure to find the max pixel value, then by using Process -> Math -> Divide to divide all pixels in the image by the max pixel value. Then I ran the calibration bar. Shouldn't this method also work? I tried it using M51 Galaxy image, and the top range of the color bar is 0.2 instead of 1.
>
>   run("M51 Galaxy (177K, 16-bits)");
>   run("32-bit");
>   run("Measure");
>   run("Divide...", "value=10106");
>   run("Calibration Bar...", "location=[Upper Right] fill=Black label=White number=5 decimal=1 font=12 zoom=1 bold overlay");

After dividing by the maximum pixel value, call resetMinAndMax() to reset the display range. The color bar range is determined by the display range, not the pixel value range.

-wayne

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