different color depths and efficiency

Java 2D
#1

Hello!

My question is about displaying images with different colorformat. My monitor is running in 1280x1024 32bit mode. I think this means that it has some kind of argb or rgba pixel format. I tried the following to determine this:
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsConfiguration gc = ge.getDefaultScreenDevice().getDefaultConfiguration();
ColorModel cm = gc.getColorModel();
System.out.println(cm.toString());
and the result:
DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0

hasAlpha returns false too. So it looks like my monitor is running in 24bit mode. How can that be possible? I would like to know this because I decoding MPEG4 video to some kind of pixel format and I think, if the monitor is running in another format then it will be converted before displaying. So if the monitor in 32bit argb mode then I have to decode to 32bit argb which makes the displaying faster(no need for colorspace convert). Is this correct?
Thanks in advance,
Bendeguy

#2

I haven’t seen a monitor yet that had an alpha channel - then you could look though it and see a bunch of wires.

#3

And I haven’t seen any transparent printer. But this alpha chanel option is there so I think hasAlpha() can return true. Maybe I worded incorrectly. What I would like to know is which color formats can the monitor handle without any conversion. I thought that it depends on the current display settings. So you say that a monitor can’t have any alpa channel, which means that I have to convert my video to RGB or BGR pictures(and I can forget ARGB and RGBA)?

Greetings,
Bendeguy

#4

the monitor has nothing to do with it, it’s all about the graphics-card, it has a framebuffer that might have an alpha-channel. even if it has ARGB, that doesn’t mean that it’s as fast as RGB, blending is always expensive. I haven’t seen a native RGBA format, because ARGB (or ABGR) just makes more sense on a framebuffer.

You’re always safe when you use
getCompatibleImage() and check the color-format