Re: What color from the Color Picker?

Posted by Wayne Rasband on Oct 17, 2009; 7:12pm
URL: http://imagej.273.s1.nabble.com/What-color-from-the-Color-Picker-tp3690712p3690713.html

On Oct 17, 2009, at 10:59 AM, Gabriel Landini wrote:

 > Hi, In the color picker I have 2 arbitrary colors set as
 > fore/background. If one uses those with an 8 bit image to
 > draw some pixels using the pencil tool, they appear as a
 > grey tone. I've looked in the IJ source, and found that the
 > FG color can be obtained from:
 >
 > Toolbar.getForegroundColor();
 >
 > My question is, what color does it correspond to, so one can
 > use it in for example:
 >
 > ip.putPixel(x,y, color)
 >
 >  guess that this color is mapped to some gray value for
 > 1-channel image types. But how is that done?

Use the ImageProcessor.getBestIndex() method to convert a Color into a  
LUT index or 8-bit pixel value.

    color = Toolbar.getForegroundColor();
    value = ip.getBestIndex(color);
    ip.putPixel(x,y, value);

-wayne