There is a static list of handlers which wx.Bitmap examines when a file load/save operation is requested. Some handlers are provided as standard, but if you have special requirements, you may wish to initialise the wxBitmap class with some extra handlers which you write yourself or receive from a third party.
To add a handler object to wx.Bitmap, your application needs to include the header which implements it, and then call the static function wx.Bitmap.AddHandler.
Note: bitmap handlers are not implemented on all platforms, and new ones rarely need to be implemented since wx.Image can be used for loading most formats, as noted earlier.