Here is the GIF image of text with anti-aliasing blending to white and transparency then outside the text.
... and another background.
Recall this was shown in Example 1 to indicate how anti-aliasing to a fixed background color creates a "halo" effect.
Now here is essentially the same example, but using a 24 bit PNG image created in photoshop with anti-aliasing using the alpha channel to gradually blend the text color into whatever background is beneath it.
... and the second backgrond.