24bit Color to 8 bit conversion problem

Posted by Yasunari Tosa on Dec 20, 2006; 7:04pm
URL: http://imagej.273.s1.nabble.com/t-for-tabulation-to-the-log-window-tp3700755p3700758.html

Hi,

This happens on ImageJ 1.36b (I have not tested this on the latest).  

When I load an 24 bit color image, then Image->8bit creates all color
becomes equally
added, i.e. (R,G,B) = (255, 0,0) or (0, 255, 0) or (0, 0, 255) does not
matter.
All becomes 85.

I think that 24 bit color -> 8 bit should use the NTSC conversion routine:
      val = 0.114*B+ 0.587*G+0.299*R

Is there a reason why the conversion was not done this way?

Thank you.

Tosa

--
Yasunari Tosa, Ph.D.

Senior Scientist
Retica Systems Inc.           Phone: [phone]
201 Jones Road                Fax  : [phone]
Waltham, MA 02454             Email: [hidden email]
USA