can I create a gmapsupp.img with all open source software?

First off, I am a Computer Engineer who well understands the theory,
electronics, and programming of handheld GPS units. I finally swallowed
my pride after years and years of compass/map land navigation and bought
an Oregon 450 that I use primarily for tracking my mountain bike routes
and for waypointing POIs in my life.

I do like the 450 hardware and it almost does what I need...all except
the fracking proprietary image format used to store maps in the unit. As
a matter of principle I refuse to buy MapSource or to use MS-Windows.

I only bought that particular unit because I seemingly misinterpreted
online discussions about how I could use "free" maps in my Garmin GPS.
Yeah, there may be "free" maps available online to use with the Garmin
products but what is conspicuously missing is a PURE OPEN SOURCE tool to
take geo-referenced bitmap images and create a viable gmapsupp.img file
that can be loaded into the Garmin GPS. I've played with different map
data-sets and open source programs like qlandkartegt but there always
seems to be a step missing between using the map data on a PC and
preparing a viable Garmin image file. An occupational hazard of open
source is that documentation is always lousy, if it exists at all. So,
there may be a function or tool created to deal with the images files but
I cannot find anything open source to do it.

I'm looking for two things really, a well documented process to start
with georeferenced TIF 24k quads and produce a valid image file, and a
list of ALL OPEN SOURCE programs ("working" open source programs would be
nice) I'll need to do it.

Comments?

Rob wrote:

Free TOPO-maps are available here http://www.gpsfiledepot.com/ there are MAC
versions if that is what you prefer to Windows. They also have tutorials on
how to make your own maps, might be of interest to you. They even have
instructions on how to install Mapsource for free.

--
Hasse

On Tue, 29 Mar 2011 18:49:15 +0200, Hasse K wrote:


As far as I can tell, none of the tools on that site are pure open
source, nor did I see anything that does what I'm asking for in the
original post. Free maps are only part of the equation. If I cannot
create a viable gmapsupp.img using open source tools then it is all for
not...

Open source means that the actual program code is freely available for
reverse engineering, independent review, disassembly, modification, etc.
It's not about MAC vs Windows. It's about having the source code and
being able to build the tool on any platform with a compatible user
interface specification: windows, Mac, Linux/X11, etc. It's also about
being able to diagnose and fix bugs independently of whoever provided the
software, or even enhancing the software for my specific needs.

I won't use Internet downloaded software on my machine that is supplied
in binary only format. Everything gets built locally in a clean-room
setting as part of my cyber-security process.

On 29/03/2011 16:57, Rob wrote:


I'm not sure what are wanting to do. Firstly, a Garmin 'gmapsupp.img'
file a vector map format. Trying to convert a TIF bitmap to a vector map
is going to be complicated and/or unreliable, unless you trace it all
manually.

If you just want to use the TIF as a bitmap image on the Oregon, you can
use the "Garmin Custom Maps" feature (no need for a gmapsupp.img). All
you have to do is convert the TIF to JPG, then create a suitable KML
file for georeferencing it. Garmin recommend using Google Earth for the
georeferencing, but as its just an XML file you can just use a text
editor etc.
See http://www.garmin.com/garmin/cms/site/us/onthetrail/custommaps
Or for the technical details:
https://forums.garmin.com/showthread.php?t=2646

If you do want a gmapsupp.img file for vector maps on the Oregon, it
would be best to start with some vector data. I don't know what sort of
map you want, and what part of the world, but worth a look a
OpenStreetMap. See http://wiki.openstreetmap.org/wiki/OSM_Map_On_Garmin
Basically, you can download some OSM map data, then use Mkgmap
(free/open source) to convert it to Garmin img format.


--
Craig Wallace
http://craig.neogeo.org.uk
http://www.neogeo.org.uk

On Tue, 29 Mar 2011 23:26:02 +0100, Craig Wallace wrote:


OK. This was my first bad assumption. I was under the impression that
ALL uploaded custom map data needed to go into the gmapsupp.img file. I
didn't realize that the units supported simple geo-tagged JPGs in the
"Custom Maps" directory on the unit.

I do understand the issues with vector vs. raster images. I assumed that
the garmin base maps were raster tiles with (some) vector overlays ...
again, probably a bad assumption on my part.




I'll have to look into this more thoroughly as it looks like qlandkartegt
does some of this for me. Whether it does it properly or easily is
another issue altogether. ;^) Looks like the program is a good starting
point but imho the interface could use some polishing.



It looks like there is a variant of OSM called OpenCyleMap that has the
level of topographic details I'd like to see. If I can figure out a curl
or wget command to grab the areas I want (eastern US areas where I
mountain bike) then I'll play with this as well.

Thanks for your time. you've given me some things to try and hopefully
pointed me in the right direction.