How to saving a transparent image?

[unknown]

I have a 32BPP png image with red background. RGB(255, 0,0)
I want to make the background transparent and save it as png with the transparent background.


I tried using CImage class but I was not able to get the transparent background.

I also tried using Gdiplus::Bitmap. I set the pixel values with appropriate Alpha values. But when I save I do not get the transparent background.

Can some one help me to solve this problem?

PB


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[Alexis]

Post by unknown
I have a 32BPP png image with red background. RGB(255, 0,0)
I want to make the background transparent and save it as png with the transparent background.
I tried using CImage class but I was not able to get the transparent background.
I also tried using Gdiplus::Bitmap. I set the pixel values with appropriate Alpha values. But when I save I do not get the transparent background.
Can some one help me to solve this problem?

You can ask on advanced Win32 ng (http://tinyurl.com/yjy3ajr)
where it has often been explained.. (locking, etc)