Understanding Offline Maps
Why are offline maps useful?
Map apps such as DIY Map GPS shows your GPS location and map-matches the map to your current location. There are locations where internet connection is not available such as mountains and remote areas. As maps cannot be downloaded in real-time in these locations, maps must be downloaded beforehand. Also, downloading maps through the internet will use alot of battery, so offline maps can reduce battery usage.
Why can’t Google or Apple maps be saved?
As OpenStreetMap/OpenCycleMap is a free map there is no problem saving it in the iPhone. But, the reason why Google Map and Apple Map cannot be saved is not a technical reason, but a policy issue of the map provider. Saving the maps violates the poplicy of the map provider. Therefore, GPS Apps such as DIY Map GPS use OpenStreetMap, OpenCycleMap as the default map for offline maps.
Understanding Tile Maps
The map used in DIY Map GPS is not a vector format, but a tile map image. Please refer to the link below for more information on the Tile Map.
Create Offline Map
This description is commonly used in DIY Map GPS, 산넘어산GPS(Korea Only) and やまやまGPS (Japan Only), but the description is based on on the DIY Map GPS. Offline maps can be made in the four ways below.
- Directly download OpenStreetMap/OpenCycleMap from app
- Use MBTiles SQLite downloaded through MOBAC(Mobile Atlas Creator) in DIY Map GPS
- Use OziExplorer Map Data(.map), Google Earth KMZ/KMZ without conversion
- Convert RasterMap file into DIY Map DB(.diymap) using DIY Map Maker (Supported files: TIFF/GeoTIFF, MrSID, OziExolorer Map, NOAA BSB, ECW, Kashmir3D KMZ/KML, JPEG2000, Erdas HFA, JPEG and more…)
DIY Map GPS, 산넘어산GPS(Korea Only), やまやまGPS(Japan Only) use OpenStreetMap/OpenCycleMap by default. The map shown on the screen is automatically saved in the internal cache DB and can be used later offline. Also, the user can select a specific area and download maps selectively.
What is OpenStreetMap?
OpenStreetMap (OSM) is a collaborative project to create a free editable map of the world. Two major driving forces behind the establishment and growth of OSM have been restrictions on use or availability of map information across much of the world and the advent of inexpensive portable satellite navigation devices.
The maps are created using data from portable GPS devices, aerial photography, other free sources or simply from local knowledge. The data is available under the Open Database License.
The OpenStreetMap approach to mapping was inspired by sites such as Wikipedia…
- Click here for more information. (http://en.wikipedia.org/wiki/Openstreetmap)
- OpenStreetMap (OSM) (http://www.openstreetmap.org/)
- OpenCycleMap (OCM) (http://www.opencyclemap.org/)
What is MOBAC (Mobile Atlas Creator)?
Mobile Atlas Creator (formerly known as TrekBuddy Atlas Creator) is an open source (GPL) program which creates offline atlases for GPS handhelds and cell phone applications like TrekBuddy, AndNav and other Android and WindowsCE based applications. For the full list of supported applications please see the features section. Additionally individual maps can be exported as one large PNG image with calibration MAP file for OziExplorer. As source for an offline atlas Mobile Atlas Creator can use a large number of different online maps such as OpenStreetMap and other online map providers.
- MBTiles SQLite created by MOBAC can be used in DIY Map GPS.
- Homepage (http://mobac.sourceforge.net/)
- Download MOBAC (http://mobac.sourceforge.net/)
- Quick Start Manual (http://mobac.sourceforge.net/quickstart/)
- Install & Start (http://mobac.sourceforge.net/quickstart/install.htm)
MOBAC Install & Start
Creating a DIY Map(.sqlite) using MOBAC
- DIY Map(.sqlite) from DIY Map GPS is in “MBTiles SQLite” format, and when the atlast is made through MOBAC, it must be saved as a “MBTiles SQLite” format.
- When the Atlas is made as in the image below, the Atlas format must be set to “MBTiles SQLite” . (Important!)
Copy the created DIY Map(.sqlite) to DIY GPS App
- Copy the created DIY Map(.sqlite) to DIY GPS App through iTunes file sharing.
- Using iTunes file sharing
- Building MBTiles Sqlite(.sqlite) maps using Mobile Atlas Creator
- The corner coordinates of a map image is necessary to show a map image. The OziExplorer Map Data(.map) and KML, KMZ files contain corner coordinates of the map image.
- The OziExplorer Map Data(.map) and KML files need image files (.jpg, bmp, png) of the same name
- The KMZ files need to contain corner coordinates of the map image and an untiled image.
- Required files: Map containing corner coordinates + Map image file (Untiled image only)
- The map image only supports untiled images.
- Supported map formats: OziExplorer Map Data(.map), Google Earth KMZ/KML, Kashmir3D KMZ/KML
Using OziExplorer Map Data
- Required files: OziExplorer Map Data(.map) + Image File(jpg, png, bmp)
- Configure as the same name: e.g. sample.map, sample.jpg
- Image files of the OZF format are not supported. Please only use jpg, png, bmp files only.
- Copying the two files above to the DIY Map GPS app through iTunes file sharing.
Using Google Earth KML
- Required files: Google Earth KML(.kml) + Image File(jpg, png, bmp)
- Configure as the same name: e.g. sample.kml, sample.jpg
- Copying the two files above to the DIY Map GPS app through iTunes file sharing.
Using Google Earth KMZ
- Required file: Google Earth KMZ(.kmz)
- The map image inside the KMZ file only supports untiled images.
- Copying the file above to the DIY Map GPS app through iTunes file sharing.
Copying to DIY GPS App
- You can copy the map files of the format above to the DIY Map GPS app through iTunes file sharing.
- Supported file formats: OziExplorer Map Data(.map), Google Earth KMZ/KML
- Copy Map Data to DIY GPS App through iTunes file sharing.
- DIY Map Maker v4.1 Update!
- Supported files: TIFF/GeoTIFF, MrSID, OziExolorer Map, NOAA BSB, ECW, Kashmir3D KMZ/KML, JPEG2000, Erdas HFA, JPEG and more…
What is DIY Map Maker?
DIY Map Maker is a utility provided to create DIY Map DB(.diymap) in the DIY Map GPS app. The DIY Map Maker uses a map matching technology to match the map image with corner coordinates(WGS84 latitude, longitude) to create the DIY Map DB(.diymap).
- Download DIY Map Maker (for Windows), (Microsoft Visual C++ 2008 Redistributable Package (x86) needed)
- Download DIY Map Maker (for Mac)
How to get Free Raster Maps?
- There are lots of Free Raster Charts provided by different organizations or countries.
- Please visit OpenCPN for Free Raster Charts details.
- OpenCPN Charts Sources: http://opencpn.org/ocpn/chart_sources
How to get corner coordinates?
If you don’t know corner coordinates of map image file, you can get them using “Image Overlay of Google Earth”.
- Download page of Google Earth.
- How to create Image Overlays in Google Earth.
- Using The Image Overlay Tool In Google Earth.
1) Create DIY Map DB(.diymap) through map image(JPEG) file and corner coordinates(WGS84 latitude, longitude)
A DIY Map DB(.diymap) can be created by setting the corner coordinates of of scanned map images or images from the internet. An example of a map of the Mt.Fujisan map and corner coordinates is given.
- Download Mt.Fujisan map of Japan (fujisan.jpg)
- Corner coordinates of the Japanese Mt.Fujisan(north, south, east, west order): 35.44310199 35.30243299 138.82462699 138.63233299
Select fujisan.jpg from “Select Map Image File”, then in “Georeference with bounding box as 4 numbers” enter the values “35.44310199 35.30243299 138.82462699 138.63233299″ and press continue. (Note! The map image filename must be in english characters.)
Generally, the default zoom level value will suit most uses.
The map image will be made into tiles and DIY Map DB(.diymap) created in the last stage.
The created DIY Map DB(.diymap) is saved into DIY Map GPS app through iTunes file sharing.
- Creating DIY Map(.diymap) through map image(JPEG)
- Importing DIY Map using iTunes file sharing
2) Kashmir3Dのマップカッターで生成した地図使用可能(Japan Only)
カシミール3Dのマップカッターで生成した地図イメージ(custom_map.jpg)は外郭情報ファイル(doc.kml)でDIY Map DB(.diymap)を作る方法を紹介しています。例として下記の日本の富士山の地図イメージと外郭情報を使用しています。
- 動画ガイド - DIY Map Maker – カシミール3D(custom_map.jpg, doc.kml)
- 動画ガイド - iTunes file sharing