#GarminCustomMap
The GarminCustomMap plugin for QGIS 2.0 and later exports the current map canvas to a .kmz-file, which is compatible with Garmin`s Custom Maps format for handheld GPS units. That way individual maps styled in QGIS can be used as background (raster) maps on the compatible Garmin GPS units, like Alpha, Astro, Dakota, Oregon, Colorado, GPSMAP 62 series, GPSMAP 64 series, GPSMAP 78 series, Edge 800, Montana, Rino, eTrex® 20 and 30.
A Garmin Custom Map (.kmz-file) is a zip-file containing, one or more jpg-images (tiles), and the georeference infomation in a text-file (doc.kml). Each jpg-file is limited to 1 megapixel (e.g. 1024 x 1024 pixel or 2048 x 512 pixel) and should notr be heavier than 3MB. The time for drawing the map on your GPS unit is affected by the file size of the jpgs (which can be controlled by tile size (number of rows and columns) and JPG-compression (quality)).
With the "Opimize tile size automatically"-flag checked (default), the tile size will be adjusted to the short side of the map in order to produce the minimum number of tiles for the map area.
The number of Custom Map jpgs (Tiles in your .kmz-file) on a GPS unit is usually limited to max. 100 jpgs (across all Custom Maps on the unit). However, newer Garmin GPS units (Montana, Oregon 6x0, and GPSMAP 64) have a limit of 500 tiles on the device in total.
When "Skip production of empty tiles" is checked (default), tiles which are entirely white (white is the default background color) are not produced in order to minimize the consumption of the limited space on the GPS device.
To upload the produced Custom Map to your GPS unit, copy the resulting *.kmz file into \Garmin\CustomMaps directory on the GPS unit.
Compatible Garmin device series are: Alpha, Astro, Dakota, Oregon, Colorado, GPSMAP 62 series, GPSMAP 64 series, GPSMAP 78 series, Edge 800, Montana, Rino, eTrex® 20 and 30
For more technical details and limitations regarding Garmin Custom Maps see: https://forums.garmin.com/showthread.php?t=2646
For more information on Garmin Custom Maps and compatible GPS units see: http://www.garmin.com/us/products/onthetrail/custommaps
(C) Norwegian Institue for Nature Research (NINA), http://www.nina.no Stefan Blumentrath (email: stefan dot blumentrath at nina dot no)