Calibrate a map with data on map sheet
If you scanned  a map or you downloaded one form the internet, you will usually find the necessary information on the map sheet. Some examples of a Canadian map are listed below.

Here you see among other things the map projection UTM (pr = UTM), the UTM zone (zn = 11n) and the map datum North American Datum 1983 (dm = NAD83). In the corners of the map you will find the exact geographical coordinates of that corner points (rp = ...). These are in this case the essential data to calibrate the map.

Addition information
A JPR-file can contain a number of additional data. It's good to determine the map part of the sheet. This can be done with describing the vertices (pixel coordinates vp1, vp2, vp3, ...) starting in the top left corner then and clockwise round. Usually, the four corners. The polygon can also be described in geographic latitude and longitude (vg1, vg2, vg3, ...). The latter can be useful in cases where the edges of the map long length and width degrees walk (for example, American and Canadian cards). For further information: see page "Introduction to calibrate maps" .