When I hung a treasure map in an item frame and pressed S to walk backwards away for some ten blocks, weird thing happened. There rendered strips all over the map. Walk closer and the strips change their shapes & sizes. 

This reminds me of the colorful strips that appear when you try taking a photo of your computer screen using your phone. However, such strips have no reason to appear here. They stop me from seeing the treasure map clearly from a near distance.

This issue has not yet been tested with normal hung-up maps.