Simple way to replace white with transparent in .png?

[ovideo]

Hello.

I am working on a script and i've hit a wall. Short story: i'm at the point where i need to make a .png transparent, like you can do manually with irfanview (all the colors remain the same, only white becomes transparent). I don't need anything fancy, but it would help if it were very fast... perhaps a color remap of some sort?

This is where it goes in:

; either make the png at $_PngPath2 transparent...
$_Image = _GDIPlus_ImageLoadFromFile($_PngPath2)
; or make $_Image transparent
_SetBitmap($_gui, $_Image, 255, $_m, $_m) ; -> puts the png on the GUI

If the png is transparent it is displayed properly, but unfortunately it's never transparent.

Help, please?

[ovideo]

Problem solved, using ImageMagick Object, as presented

$img = ObjCreate("ImageMagickObject.MagickImage.1")
   $ret = $img.Convert($_PngPath2, _
        "-transparent", "white", _
        $_PngPath2

edit: my other problem had an obvious fix, seems i'm too tired.

Edited October 11, 2011 by ovideo