Do not hesitate to contact the technical support if you are having trouble importing a map.
Importing a map
Tapping on "+" in Multiplans opens the "Add maps" screen, which explains the various ways to import a map.
In summary, they are
- Web gateway
- iTunes file sharing
- Import by email (tmap format only)
- Import from the iPhoto library
- Direct import of a camera shot.
Maps can be transferred by a simple drag-and-drop
between Apple devices, thanks to AirDrop.
On the other platforms, use any of the other transfer methods.
Possible map formats
■ Format OSZ
Use Mobile Atlas Creator
to create OSZ maps with data from various map web sites, in particular OpenStreetMap
. An OSZ map can contain several (contiguous) zoom levels with different images at different scales. OSZ maps are already calibrated.
The app MAPC2MAPC (Win) can also create OSZ maps.
■ Standard image formats
: jpg, tiff, png, bmp.
Images in this format can be imported directly in Multiplans.
If the file is very big (>400 Mb
), it is recommended to convert it into the format tmap
■ Format tmap
Multiplans converts internally all maps into the tmap format, which is a fast format allowing arbitrarily large maps
Use TmapCreator (or Multiplans itself!) to convert a map into the tmap format. TmapCreator can process not only image files, but also folders containing map tiles.
■ Format zip
The zip format is useful only on Windows/Linux computers, where TmapCreator can't be used, to import very large maps.
The zip archive must contain the map image, either in a single file or split into tiles of size 256 x 256 pixels for instance, and (optionally) a calibration file. Importing a map split into tiles is quite fast and requires little memory. More information on zip archives
Calibration of a map in Multiplans
Maps need to be calibrated to be used with GPS positioning
. Recall that maps in the OSZ format do not need calibration since this calibration is done automatically. (Most maps on multiplans.net are also already calibrated).
To calibrate a map in Multiplans, tap on button ⓘ
, at the right of the map name, to open its "Map info" screen.
Two calibration methods are available:
Common projections are pre-defined in Multiplans. Less common projections can be specified by their EPSG number. To find this number, visit for instance SpatialReference.org and search there for projections by country. See also page EPSG codes.
- Method with "Interpolation": interpolation from the geographical coordinates of 2, or 4, calibration points. This method generally gives good results for maps covering a "small" area, say less than 100 km. If the lines of constant longitude (or latitude) are aligned vertically, resp. horizontally, 2 calibration points are enough. Otherwise, specify 4 points.
- Method with "Cartographic projection": Only 2 calibration points (or 1 point and the resolution of the map in meter/pixel or degree/pixel) and the map cartographic projection need to be specified. The cartographic projections of national maps of many countries are pre-defined and can simply be selected from a well-presented list. Since this calibration method does not involve any interpolation, it is exact: it provides a perfect calibration with just 2 calibration points, even for very large maps.
New projections with custom parameters can also be defined easily in Multiplans.
Defining calibration points
The three screenshots below show the definitions of 2 calibration points. The first one is at the top-left corner of the map (pixel coordinates: 0, 0); the second one is near the bottom-right of the map image (pixel coordinates: 3850, 2399).
The calibration points can be moved by simply scrolling the map and tapping on the point (= the blue crosshair) once it is correctly placed. By tapping on the crosshair, the pixel coordinates for the selected calibration point are stored.
In the fields "Longitude" and "Latitude", enter the geographical coordinates of the point (usual GPS coordinates). The "Grid coordinates" are optional and can be entered only when using the "Cartographic projection" method. The grid (or projected) coordinates are often shown on the map by a regularly spaced grid. They would correspond for instance the Swedish coordinates on a Swedish map. On the screenshots above of a swiss map, the grid coordinates are Swiss coordinates.
When entering the longitude and latitude, the corresponding grid coordinates are calculated automatically. Conversely, when entering the grid coordinates, the corresponding longitude and latitude are automatically determined. If the grid coordinates are shown on the map (as in the above screenshot), it is obviously quite convenient to use these coordinates. A button "Set to current location" can be tapped to fill-in the longitude and latitude coordinates with the current GPS location.
Once two calibration points have been entered (or 4 if you chose to define 4 of them), Multiplans calculates automatically the resolution of the map.
Tip: When using 4 calibration points, it is best to place those points near the 4 corners of the map (which is their default positions). When using only 2 calibrations points, they should be placed close to two diagonally opposite corners to maximize the accuracy of the calibration.
Google maps can be used to find the longitude and latitude coordinates of any point in the world: right click on a point in Google maps
, and select "More information about this place".
How to convert sexagesimal coordinates (degrees, minutes, seconds): longitude and latitude coordinates are sometimes given in sexagesimal, whereas Multiplans accepts only decimal coordinates (in degrees and fractions of degrees). To convert sexagesimal coordinates in decimal coordinates, simply divide by the minutes by 60 and the seconds by 3600.
Example: 6 ° 3 '45.3'' = 6 + 3/60 + 45.3/3600 = 6.0625833 °
Two calibration points have been defined on this map. In the calibration screen, one can enter either their longitude and latitude coordinates (usual GPS coordinates, WGS84 datum) in the appropriate text fields "longitude" and "latitude", or their projected coordinates (here swiss coordinates) in the text fields "grid coordinates". Once these coordinates have been entered in the calibration screen, Multiplans calculates automatically the resolution (in meter/pixel) of the map.
On mapviewer sites, the resolution is often nice round numbers, like 5 m/pixel for instance. If one has chosen to define only one calibration point, the resolution must be entered manually.
See the Support forum which contains further examples how to calibrate maps.
A calibration file might already be provided with your map. Those have extensions like .map, .TAB, .TFW, .JPW, .PGW, etc.
Multiplans can read automatically .map calibration files(*), and also ref.txt
calibration files, see page zip archive
. The support for .map calibration files is only partial and the conversion can be inaccurate for exotic projections. Multiplans converts .map calibrations into a bilinear interpolation with 4 calibration points, those written on lines MMPXY and MMPLL in the .map file.
The calibration information stored in the other calibration file formats cannot be interpreted automatically by Multiplans, but it can be helpful to speed-up the manual calibration of the map (to copy-paste the pixels and geographical coordinates of calibration points for instance). More info on other calibration files.
Note: The program MAPC2MAPC (windows) can open maps with all kinds of calibration files (ECW, GeoTIFF, MAP, KAP, JPR, TAB, TFW, JPW, PGW and KMZ files and save them in the OSZ format, which can be imported directly in Multiplans.