compare the picture

Posted by sandy sut on Feb 22, 2011; 4:35pm
URL: http://imagej.273.s1.nabble.com/compare-the-picture-tp3685587.html

I am going to compare the improvement of the pigmented lesions before and after treatments of laser. I change the color picture to 8 bit and use the analyse menu but the problem is I can not set the same value of the threshold to each picture in order to get the same area of coverage. I want to know that these values can be compared and reliable?