+
+PNG Images
+----------
+
+Prior to 2.5 the PNG image handler would convert all alpha channel
+information to a mask when the image was loaded. Pixels that were
+more than halfway transparent would be made fully transparent by the
+mask and the rest would be made fully opaque.
+
+In 2.5 the image handler has been updated to preserve the alpha
+channel and will now only create a mask when all the pixels in the
+image are either fully transparent or fully opaque. In addition, the
+wx.DC.DrawBitmap and wx.DC.Blit methods are able to correctly blend
+the pixels in the image with partially transparent alpha values.
+(Currently only on MSW and Mac, if anybody knows how to do it for GTK
+then please submit a patch!)
+
+If you are using a PNG with an alpha channel but you need to have a
+wx.Mask like you automatically got in 2.4 then you can do one of the
+following:
+
+ * Edit the image and make all the partially transparent pixels be
+ fully transparent.
+
+ * Use a different image type.
+
+ * Set a mask based on colour after you load the image.
+
+
+