Hi Todd,

I think, you should be able to make this conversion with GDI+ image class, which is available here in downloads section.
The following code (which creates a negative image), will show the idea:

If Not "gpImage" $ Set("Procedure")
	Set Procedure To gpImage Additive
EndIf

gdip = CreateObject("gpInit")
img = CreateObject("gpImage")
img.Load("sample.jpg")

For i = 0 to img.ImageWidth-1
	For j = 0 to img.ImageHeight-1
		clr = img.GetPixelColor(i, j)
		img.SetPixel(i, j, BitNot(clr))
	EndFor
EndFor

img.SaveAsJPEG("negative")

Please note that SetPixel will not work with 8 bit indexed GIF image, so you'll need to increase number of colors before the conversion using PixelFormat property. You can change it back later.
And I'm not sure about the performance, probably C++ for 53,000 images will be more appropriate.

HTH,
Alexander

>I am looking for a progamatic way to change the background color of GIF's from somehting that is near black (varies by image) to white. Does anyone have a way to do this - GDI+ maybe?
>
>An app I am working on has a database of over 53,000 images that do not have their backgrounds, and thus the transparency color, set to white.
>
>Thank you,
>Todd Cottengim
>Redding, CA