I have a set of TIFF maps that I want to load onto Garmin GPS 62s units. The maximum size for each tile on the GPS is 3Mb and less than 1 million pixels. I manually produced one tile, following this workflow:
- Convert whole TIFF map to JPG using IrfanView
- Manually crop the image to be less than 1 million pixels (i.e. 1024X1024) and compress to be less than 3Mb.
- Add JPG to QGIS and georeference using the georeferencer tool.
- Add same JPG image to Google Earth as an Image Overlay.
- Use the Extent information from the georeferenced JPG in QGIS to fill out the extent boxes in Google Earth.
- Save as KMZ file.
- Add KMZ file to Garmin Basecamp.
- Add KMZ to GPS unit with Basecamp.
This is obviously a slow and fiddly process which I am reluctant to repeat 100 times to produce all the tiles needed.
Is there a way to automate sections of this?
Specifically I imagine the follow are possible, but don't know of any tools to do it:
- Automatically divide one georeferenced raster into multiple tiles of given dimensions, retaining geocoded information, in QGIS.
- Export multiple tiles into a KMZ file in QGIS
This would make the process a lot quicker. The closest tools I have found is the GarminCustomMaps plugin for QGIS, but this just takes a JPG image of your current map canvas - great for using with multiple vectors etc, but when zoomed out with large raster files, I just get a very pixelated image which is useless for reading on a GPS. Zooming in more to increase the resolution negates the point of it, as you'd have to repeat it multiple times.