According to the Minecraft WIKI, the origins of all maps should be 64 down from the top edge and 64 to the right of the left edge. Now, maps appear to have their map origins at the map center.

I created this map by going to 0, 0 and starting a locator map. I then zoomed it out to max and moved around to expose all of it. My understanding is that returning to 0, 0 should place me in the upper left corner, 64 in and 64 down instead of at the map center.