float overlayAlphaFloat = (float)overlayAlpha / 100.0f;
Bitmap newBmp = new Bitmap(destBmp.Size.Width,
destBmp.Size.Height);
Graphics newBmpGraphics = Graphics.FromImage(newBmp);
newBmpGraphics.DrawImage(destBmp,
new Rectangle(0, 0,
destBmp.Size.Width,
destBmp.Size.Height),
0, 0, destBmp.Size.Width, destBmp.Size.Height,
GraphicsUnit.Pixel);
Bitmap overlayBmp = new Bitmap(bmpToOverlay.Size.Width,
bmpToOverlay.Size.Height);
overlayBmp.MakeTransparent(overlayBmp.GetPixel(0,0));
Graphics overlayBmpGraphics = Graphics.FromImage(overlayBmp);