how to display letters or images on transparent background,

(and if possible, platform independent)

i'm looking for a programmatic solution (even a command line solution) which will enable me to display alphanumeric letters on the screen, without the Window / Form's background color.

i'm using mainly Windows (xp), but i'd love a solution that can work on modern linux distros.

i know how to make a whole window / form transparent, but that doesn't help, since the letters themselves must be 100% opaque, and background must be 100% transparent.

(I know how to make a window on top of everything.)

It might be possible to convert the letters to a transparent GIF or PNG, but i don't know which technology will NOT show it's own background.

i'm using mainly Python an开发者_如何转开发d Visual Basic, but i don't mind using other platforms.

Thanks

Sorry there is no platform-independent way. What you are talking about is a function of the capabilities of the GUI subsystem supplied by the OS (or by a third party layer on top of the OS). On the Mac for example there is explicit support for rendering the background of windows independently of the window content but doing so is specific to that platform. MS Windows, X-Windows, NCURSES, QT, there are many different APIs for rendering to the "screen" (where screen can be a screen or a PDF or a printer or you name it).

You'll need to know specifically what output device you're targeting and read the docs and write your code for that system.