In order to correctly place an overlay on the map you need to know three things:
1. Upper left corner coordinate 2. Lower right coordinate 3. Projection of the image. Projection is less important if the area is small, like in less than 200 miles on a side. If it's greater than that, then you'll need to take into account how the original image was made. If it's a satellite image, the slant angle is very important as high slant angles will skew the image quite a bit. The projection that Google uses is called "World Mercator" which uses parallel latitude and longitude lines. As the latitude increases, the "stretching" of longitude increases to the point where it's impossible to depict the world in this projection (about 85 degrees north or south). You can locate your corners by overlaying your image on the map and moving it around until you get a match on Google's map. That's not a trivial thing to do but if you don't know the coordinates of the corners, that's about the best method. -John Coryat -- You received this message because you are subscribed to the Google Groups "Google Maps JavaScript API v3" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-maps-js-api-v3/-/uatV0aat7dIJ. To post to this group, send email to google-maps-js-api-v3@googlegroups.com. To unsubscribe from this group, send email to google-maps-js-api-v3+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-maps-js-api-v3?hl=en.