6.3. Raster Image Base Maps

Raster Image Base Maps provide for access to Base Map data when the device is not online. They can also be used to support custom data (such as high resolution satellite or aerial photo data) in scenarios where online map sources are insufficient.

CartoMobile supports a variety of different map formats to provide the maximum flexibility for users. Standard formats, such as MrSID, GeoTIFF, ECW, JPEG, and JPEG2000 provide for easy import from data libraries. CartoMobile also allows the use of pre-rendered data by using a special .sqlite database format which can be created by Cartographica, our macOS desktop GIS.

[Note]

In order to work with CartoMobile, the data in use must be georeferenced to a known CRS (Coordinate Reference System, or Projection). For some file formats, such as GeoTIFF and MrSID, this data is sometimes included directly in the file itself. If it is not, it can often be added by using sidecar files, such as .tfw, .jpw, .sdw, and .prj files. If CartoMobile does not recognize this information, it will display a warning indicating the layer cannot be reliably used without adding it.

Adding Raster Imagery

  1. Choose Change Map from the gear menu to bring up the Change Map window

  2. Tap the Edit button

    For all Local Maps, you will now see the blue chevron button (it looks like a greater-than symbol) on the right, providing the edit function for that map

  3. Locate the Map you want to edit and tap the blue chevron.

    The Map Editor will slide into view

  4. Choose Import Raster Image in the Base Maps area of the Map Editor

    The Raster Image selection page will slide in, showing a list of every raster image file of any supported type.

  5. Select each of the raster images you want to add to the imagery layer by turning the switch on

  6. Once one is selected, tap Import to create the new raster layer

  7. Tap Done to commit your changes to the Map

    The Map Editor will slide out, showing the Map list in edit mode

  8. Tap Return to return to the Map you were previously viewing, or Done to return to the Map list in map selection mode (you can always choose the same map you were using before by tapping it again from this list.

6.3.1. Reducing clutter with RasterPacks

Due to the relatively limited file manipulation of the iTunes app and the small screen, it's sometimes useful to aggregate the raster images into a separate directory structure. To provide an easy way to select a group of images, CartoMobile supports what we call the .rasterpack, which is just a directory with the extension .rasterpack containing one or more image files and their auxiliary files. By putting your imagery into a .rasterpack, you will be able to select all the imagery as one element.

[Note]

Take care when replacing RasterPacks. For best results, when you add files to, or remove files from, the RasterPack, you should remove and re-add the RasterPack to your Map.