This site uses cookies to offer you a better browsing experience. Find out more about how to manage cookies, or dismiss this message and continue to use cookies.

Garmin "Custom Maps" (Raster Imagery Support)

It had to happen sooner or later... Right now it is a DIY project which won't appeal to everyone... but it is better than nothing! :)


  • Boyd 2045 Points
    Whoa - that's quite a surprise. I knew somebody would eventually crack their raster image format, but didn't expect it to come from Garmin itself!

    Will have to play around with this. Hopefully there's a better workflow which will let me use my substantial existing library of raster imagery in Globalmapper without all the fussing with Google Earth.

    Very cool. 8)
  • This is really awesome. As a history buff, i have been able to download historical pictures (WWII) ear photos, save them as JPGs, overlay them on google earth, and place those photos with great accuracy on my Oregon. Now i can basically explore a WWII site as though it was still here. For example, my home is located on an old WWII Navy field (that no longer exists). But, i have access to WWII photos that i can downlowad into Google Earth . I can still reference it to old roads, streams, etc that ensures i have correct placement of the overlay. So, i can walk out my door and know exactly when i am on a runway, taxiway, etc. I am still trying to absorb all the possiblities. Also, i can save ANY Google Earth image, then bring that image back as an overlay, and download that on my Oregon. Very cool
  • Boyd 2045 Points
    Have been playing around, and it definitely works on my Oregon 400t. Here are some examples of a USGS 24k topo and the NJ 2007 digital orthophotography at 1 foot per pixel resolution.

    I did not need to use Google Earth at all. I used Globalmapper which can directly export a .kmz file in the correct format. All I had to do was create a \Garmin\CustomMaps folder on my Oregon and drag the file into it. It literally only took me a few mouse clicks to make these maps and less than a minute to have them available on my Oregon.



    Now the bad news... It is really S L O W to render the screen. Zooming and panning are pretty painful. I also had some issues forcing a few reboots. The screen would not update when I zoomed in too far using the 24k topo map, which was about a 4MB file. The aerial image was only a 1MB file and showed better performance.

    There are some significant limits to what you can use this for - see Garmin's forum:
    Images over 1 mega pixel (1024x1024 pixels, 512x2048 pixels, etc.) will be rendered at a reduced resolution on the unit. If this is causing a problem for your map, you can split the image and use multiple jpegs inside of one kmz file.

    The max number of Custom Map jpegs you can load is 100.
    This will limit you to maps of relatively small areas. But of course this is still beta software, so hopefully it will improve in the final release.

    Garmin really deserves props for releasing this - bravo! They have just opened up the possibility of making custom maps to a huge audience, and their Google workflow makes it possible on both the Mac and PC without any special software. They have really scooped everyone else here IMO. I don't think anyone else has a free system of making very high resolution raster based maps like this.

    I will eagerly await the final release of the new Oregon software. Nice job Garmin - thanks! :D
  • Boyd 2045 Points
    Got out for awhile today using a new custom map. I used Globalmapper again to make a map at 1 foot/pixel resolution. This one contained about 80 tiles at 1024x1024 each, which is close to Garmin's limit of 100. If you do the math, the largest map you could make at this high resolution would be about 2 x 2 miles (4 square miles).

    The Oregon nailed my position perfectly by this bog at sunset. As you can see, Google Maps on my iPhone doesn't have imagery anywhere near this good. Theirs comes from the USDA, my map is from NJGIN's 2007 digital orthophotography.


    This software is quite buggy however. Tracking seems completely broken - always connects you to the start with a straight line and the tracklog looked like a single point when viewed in Mapsource. Zooming in closer than 80 feet resulted in crashes when trying to drag the map around. 50 foot zoom would crash less frequently, but 20 and 30 ft zoom would crash every time.

    But it tracks your position beautifully even at 20 foot zoom. I can see all the detail at 50 feet with this 1 foot per pixel imagery and closer zoom just makes the pixels blockier. It sure beats the pre-installed US Topo 100k on my Oregon 400t :lol:


    I have to admit, if you didn't like the Oregon's screen before, aerial imagery is not likely to improve your opinion. The photographs are pretty "dense" and don't have a lot of contrast. That made the backlight struggle on this bright cloudy day. Tilting the unit at the right angle helps a little. On a bright sunny day I think it would actually be a little better. Hiking back to the car at twilight, the screen looked great in the fading light though.

    All and all, I was quite impressed hiking around with this map. By the time the full release is available, it's going to be a killer feature that nobody else has. Very cool! 8)
  • Boyd 2045 Points
    For anyone interested in some free examples of this new kind of map, I have already uploaded 7 of them here and plan to add more:

    If you don't have a GPS compatible with these, the custom maps are really just .kml files which can be used by various other applications, most notably Google Earth. When opened in Google Earth, you can view them in 3d and fly around. They will be "draped" over the topography of the land as well.


    Most of the maps I've uploaded come close to maxxing out the capabilities of this format in terms of coverage and quality. My experience is showing that the largest USGS 24k topo you can make with decent quality is about 19 miles x 19 miles (~360 square miles). To get the highest quality however you can only cover about 11 miles x 11 miles (~120 square miles). These are the equivalent of about 10 feet per pixel for "good" quality and 6 feet per pixel for "best" quality. I felt too many details were lost when trying to cover areas larger than this.

    With aerial photography, it depends on what the native resolution is. I have some very nice imagery at about 1 foot per pixel. This results in a very small mapped area in Garmin's format however, about 1.7 miles by 1.7 miles. My map of Philadelphia is an example of this. See also my map of Island Beach State park. I downsampled this to 2.8 feet per pixel and it still looks pretty good. I reached Garmin's limits with a mapped area 2.7 miles x 10 miles (270 square miles) in that example.
  • Boyd 2045 Points
    The author of MOAGU (Mother of All GPS Utilities) has posted a free program for creating these Garmin Custom Maps. I have not tried it myself, but others have been praising it. More info here:
  • Boyd 2045 Points
    Garmin has released updates for the Oregon, Colorado and Dakota which are supposed to address some of the bugs. Haven't had a chance to try this yet myself, but other users are reporting faster zooming and panning with less crashes.

    The new versions for different units are as follows:

    Colorado 300/400 - version 3.10
    Oregon 200/300/400 - version 3.30
    Oregon 550 version - 2.60
    Dakota 10/20 version - 2.30
  • Boyd 2045 Points
    Heh, this is starting to sound a bit like one hand clapping. :lol:

    But if anyone is interested, Garmin has put up a new page on Custom Maps:
  • gatorguy 329 Points
    Boyd, it might seem like there's little interest here, but I'm sure Garmin's Custom Maps were great news to a lot of our visitors. Keep the updates coming :) I'm sure it's much bigger news in some of the forums more focused on handhelds/outdoor.
  • Boyd 2045 Points
    Thanks Gator, now I don't feel so lonely. 8)
  • Smee! 0 Points
    Thanks Gator, now I don't feel so lonely. 8)
    Boyd, you should know I have spent the last 4 days reading for hours trying to decide on a new GPS, I recently lost my eTrex on a jeeping tour in Sedona. I've been following (google stalking) your posts across multiple forums. You appear to be very knowledgeable and have constant praise for the Oregon despite some of it's flaws. I've recently purchased a 400t (I'm an avid hiker/biker) and looking forward to overlaying the free 24k maps on top of the 100k. But what really convinced me was this thread, I'm really looking forward to making custom map overlays out of google earth. I got a really good deal at

    edit: I should add I was bouncing between the PN-40 and the 60CSX.

    329.95 and free second day air shipping.
  • Boyd 2045 Points
    Thanks for the kind words. Now I hope that the Oregon lives up to your expectations! It may not be the perfect product for everyone, but it is my favorite now that we can make our own raster-based maps. I do wish the screen were better though.

    That is a good price - Costco also has the Oregon 400t for $350 which isn't bad either (especially considering their very liberal exchange/return policy).

    We're also waiting to hear Gator's impressions... he's waiting for his Black Friday Dakota 10 to arrive and agonizing over whether he should have gotten an Oregon instead. :lol:

    If anyone else is interested in getting a Garmin handheld that works with these new custom maps, have a look at our "Black Friday" thread. I believe a few of the deals there may still be available as of this writing.
  • gatorguy 329 Points
    The West Marine manager told me to drop back by when I get the Dakota and he'd be happy to let me borrow the 400 again for a couple of hours just to compare the two. I leaning more towards just being happy with what I ordered and stop second-guessing myself.
  • Tim 1501 Points
    I like my Oregon, but for quick "grab and go" type stuff where I don't do any pre-planning I think I'd prefer the Dakota.
  • Boyd 2045 Points
    Tim, what is different about the Dakota and Oregon which makes you feel that way? Physical size?
  • Tim 1501 Points
    Size and the slightly more readable screen at fixed angles (like on my bike or kayak).
  • Boyd 2045 Points
    Topofusion is another program which can now be used to make these custom maps. See the following for instructions:
  • redcap 0 Points
    I'm in London for a 3 day training course, and have my Oregon 450 with me to do some geocaching. Unfourtually I forgot to put my SD Card with Topo GB in my GPS device ...
    But this solution might save me! I'll try it this evening and let you know.
    Already found a custom street map of London
    Sounds very promising!

  • redcap 0 Points
    I found 12 geocaches in 2 days. The custom map of London helped me a lot. Thanks for posting the info in this treath!
  • Boyd 2045 Points
    This was just posted in Garmin's support forum for the Custom Maps feature. It sounds encouraging; maybe we'll be able to create more useful maps in the future!
    We are excited about the continued interest and adoption of Garmin Custom Maps by Garmin customers. We are evaluating the performance impact of increasing the maximum tile size and overall tile count. If these improvements can be achieved, our limits may be raised. However, structural differences in the file format between Garmin Custom Maps (KMZ) and Garmin BirdsEye (JNX) will prevent Custom Maps limits to ever reach the overall capacity of Garmin BirdsEye.


  • gatorguy 329 Points
    I had read the PR on this a few days ago and paid a visit to the website. There's also been a news article posted at another site. Haven't yet had an opportunity to give it a spin, but I intend to. Do you represent OKMaps in some way? Believe you're both located in Italy.
  • Boyd 2045 Points
    Here's a new free tool for making custom maps. I haven't tried it myself yet, so please post your impressions if you do.
  • Finally cracked the code on what a guy can do with the custom map feature. I frequent a small island in Japan called Ie Shima. I spend a lot of time there and have done a lot of research on WW2 especially the landings and taking of Ie Shima. I loaded the following custom map into my eTrex 30 and next time I go to the island I'll be real darn close to the landing sites and can follow the progression of the invasion.

    Super, super cool.


  • Not sure why my photo didn't load but the link is there between the IMG tags.
  • Boyd 2045 Points
    You need an image to use the img tags. :) The link you posted is not an image, it's a URL where somebody can view your image on Flickr. I don't use Flickr myself, so not sure how to configure it. However, usually it's possible to link directly to the image itself (the actual .jpg file). But I am unable to do this for you here. If I right-click the image I get a notice that you have copyrighted it so I guess that's the problem.
Sign In or Register to comment.
↑ Top