Transparency values in 32-Bit RGB Image

Posted by stevenfranklee on Jun 01, 2015; 12:35pm
URL: http://imagej.273.s1.nabble.com/Transparency-values-in-32-Bit-RGB-Image-tp5012999.html

Hi All

In the ImageJ documentation is says:

"RGB Color Color Images↓ that can display 256 values in the Red, Green and Blue channel. These are 24-bit (23 × 8) images. RGB[?] color images can also be 32-bit color images (24-bit color images with additional eight bits coding alpha blending values, i.e., transparency)."

I have a question regarding alpha blending values...

Does anyone have any documentation about:
1) How to access these
2) Use them within the macro language, i.e. can I use something like - "setColor(r,g,b,transparency);"

Any help much appreciated

Best

Steven