<p>I'm using C# in .Net 2.0, and I want to read in a PNG image file and check for the first row and first column that has non-transparent pixels. </p>

<p>What assembly and/or class should I use?</p>

Of course I googled already and found the PngBitmapDecoder class, but it doesn't seem to be available in .Net 2.0?
http://msdn.microsoft.com/en-us/library/system.windows.media.imaging.pngbitmapdecoder.aspx
The above link mentions it's in the PresentationCore assembly which I don't seem to have included with .Net 2.0