how to make a transparent, invisible icon?

[eckbargus]

I would like to make a transparent icon.

That is, it should look like nothing is there, and it should be a bmp file.

How can I do this?

[Ego Eram Reputo]

Found this:

To make a transparent bitmap you must make sure that the bitmap has been converted to Indexed 256 colour. 24bit Bitmaps will not make a transparent image. Make sure that pixel (0,0) in the top left most part of the picture has the colour you want to be transparent.

And this:

I confirm that bitmaps doesn't support transparency, it is just a convention to take the top-left pixel as transparent color,

So it looks like you need to save as an 8-bit BMP, and make the top left pixel the color you wish to be transparent. BUT it doesn't look like all applications support the transarency in BMPs (like FireFox).

Q: Why BMP and not ICO file format? We have a plugin that does the ICO format Icon, Cursor & Animated Cursor Format

[eckbargus]

My idea is to replace the Windows Start button with a transparent icon (to go on my transparent taskbar) and the easiest way to do that, that I could find, is a program called Windows Start Button Changer which will only work with bmp's.

If I did it in some other format how would I do it?

[Ego Eram Reputo]

No idea. Sorry. Changing your Start Button is not the sort of question covered in this forum. Try Google or Bing.

[MadJik]

Or instead transparent, just create a picture of the background you want based on the theme you are using...