Some tools for handling Garmin .img and .mp files.
GMapTool: I’ve posted before about using GMapTool to break up a combined .img binary Garmin map file into its original segments, and also how it can identify the full names and geographical extents of Garmin map tiles. But you can also use it to join multiple .img map files into a single file, modify basic parameters in the binary file without decompiling it, strip out unwanted data (like routing and elevation data), and much more.
pGPSmap: From the website description …
- Splits large map into a set of smaller maps
- Merges holes in regions with regions’ bounds
- Splits large regions
- Splits large polylines
Haven’t used it, and as the website points out, only the first function isn’t performed directly by the cgpsmapper compiler. This was also written 6 years ago, when there might have been a substantial drawing speed increase by cutting a large map into smaller ones; not clear that it’s that useful any more.
MapExtract: Does the following (from the website description)
- Decrypt simple crypted maps (if needed)
- Convert img map file to polish format
- Extract selected map window from large maps
- Include or remove selected points, polylines and polygons
- Extract or remove selected map levels
- Convert any map object type to another
- Change the map name and map ID
- Convert map from polish to img format
- Map preview – before and after any conversion
- Send map to Garmin GPS (or set of multiple maps)
- Tool to create intersection point of all streets from level0
- Tool to split large maps automatically
- Change map ID of IMG files
This is also an older utility (last version released 5 years ago), and there are other ways to perform most of these tasks.