
The ALPHA box contains alpha values.
The RGB box contains red/green /blue values.
THE ARGB box contains ALPHA applied over RGB.

Dropping a picture in the ARGB will separate the color values from the transparency map. In case the original picture doesn't have a transparency layer, the software uses brightness values to generate it. The background of this picture is blinking with random colors, so that you can see the transparency better.

Dropping a picture in the RGB box will use only the RGB values from this picture to generate a complete result.

Dropping a picture in the ALPHA box will either apply its transparency to the RGB picture to generate the result or use it's brightness values to create a new transparency layer. In case the RGB and ALPHA pictures don't have the same size, the ALPHA one is being stretched to fit the RGB one.

Then clicking on one of the boxes will lets you save the selected picture (either ALPHA, RGB or ARGB) to a file (PNG, BMP, GIF, TIFF or JPEG).

