The picture is not transparent. It is placed as a separate object in the layout, so no gadget is close enough to be drawn on top or bottom of the picture. Not exactly what I want but with the background colour it looks okay for the moment. Best would be to have my gadgets drawn "on" it. I did not achieve this yet. Is this what you mean by "transparent"?
@ itix
"All" I had to do now was to set the MUIA_Backgroud attribute to the image file but place it locally into the VGroup instead of globally. Is this the/a proper/recommended way? What I want to do next is to include the picture into the binary, means it should not be an extra resource anymore. I read about png2c from Zapek. Is this the proper way to do it? Is there a similar program for "jpg2c"?
Ah, I remember AmiNetRadio and its green/black GUI! Great program! It's a shame that it is not developed anymore. Yes, I want to achieve a similar effect, that's it: Having one picture being the whole window backdrop. So for this I need to learn hooks?