GPSFileDepot.com
 

Free utility to create tiled raster overlays for Colorado/Oregon/Dakota models

Started by leszekp, October 20, 2009, 10:40:23 PM

Previous topic - Next topic

leszekp

Been plugging away the last week, and now have the first version ready of G-Raster, a program that will load georeferenced imagery, tile it automatically, and create a Garmin-compatible KMZ file.

Don't install KMZ files created with G-Raster into your Garmin's internal memory - put them into an external memory card in an external reader. Just a precaution for use with the Garmin beta software, and version 1.0 of G-Raster. That way, if there's a problem with the overlay, you can always just remove the card from the GPS unit.

Download link to most recent version can be found on this page:

http://moagu.com/?page_id=155

Interface is fairly straightforward:

1. Open your graphic file; supported formats are:

a. Files with embedded geodata (GeoTiff, NOAA BSB, MRSID, IMG)
b. USAPhotoMaps Big JPEG files (UTM, you'll need the UTM zone)
c. Generic graphic files with UTM worldfiles (you'll need UTM zone, and specify datum and hemisphere)
d. Generic graphic files with worldfile in any coordinate system (you'll need to specify the EPSG code)

2. Process the raster graphic file

3. Set basic options (overlay name, JPG compression, transparency in Google Earth). You can also rescale the image by a factor >= 1.0 to reduce its size (reduces resolution, but also reduces the number of tiles).

4. Create the overlay.

You should definitely check it in Google Earth to make sure it's in the right position; just remember that Google Earth imagery can be off from 0 to 100m depending on where you are. If it looks good, put it in the \Garmin\Custom Maps directory on the external data card and test it out.

Limitations:

- Maximum file pixel size is 100 million; larger than that, and you have the option of cropping it down to a smaller size

- Tile size is set to be the largest compatible with the image dimensions and a max tilesize of 1024 pixels.

Mostly functional for free (though I do ask for a small registration fee if you find it useful)

-Oz-

Dan Blomberg
Administrator - GPSFileDepot
GPS Units: Garmin Dakota 20, Garmin GPSMap 60csx, Nuvi 255W, Nuvi 250W, ForeRunner 110, Fenix 2, Tactix Bravo, Foretrex 401
See/Download My Maps!

leszekp

Thanks! Version 1.3 should be out shortly, maybe even tomorrow. It adds:

- Image preview, with a slider that changes JPG compression and shows those effects on the fly

- User-selectable image rescaling algorithm

- For images that are too large, you now have the option of either cropping or rescaling them before processing


jbensman

I can get it to work for topo maps, but this is what I get for aerial photos:



I get this if I get them from state sites or the USGS server.

If I cut and paste something from GoogleEarth, it works.  But I cannot get this to work.  The files open in GE, but not on my CO.

I am using default settings.  I tried scaling it to 2 and 3 but nothing works.

I just installed 1.4


Any suggestios?

Thanks

leszekp

Odd. No one else has seen this (or at least, no one else has reported it). And lots of people have reported success with aerial GeoTiffs. The program treats all TIFFs the same, regardless of whether they're topos or aerials. I'd need more information to figure this out.

The only difference between 1.3 and 1.4 is that 1.4 drops the pop-up at the beginning about it still being beta firmware.

You might try dropping back to an older version of the firmware, then re-installing the new firmware that supports custom maps.

jbensman

Thanks for the help (and program!)

I never had the beta firmware installed.

I tried 1.4 of your program to see if it solved it.

I did get one to work last night.

Here is an example of the data I used:

http://extract.cr.usgs.gov/Website/distreq/RequestSummary.jsp?PR=0&CU=Native&ZX=-1.0&ZY=-1.0&ML=COM&MD=DL&AL=37.16289,37.1026,-89.30824,-89.37813&CS=250&PL=QDB02HZ,QBD02HZ,QCD02HZ,n1602HZ,p1602HZ,vd902HZ

The top two caused the problem.  I made a map for each of them and it did not work.

The third one down (whch had the entire area) works.

Makes no sense to me.

Am I correct all I need to do is use default settings?

I am getting ready to leave town for a few days so I will not be able to give any more info for a while.

leszekp

Default settings should work fine. The fact that you got one of the images to work suggests some peculiarity with the imagery you had problems with; I'll take a look at the image formats to see if there's anything obvious. In the meantime, I'd recommend using the 1-meter color imagery; I've found that color imagery is actually more revealing of ground detail than higher-resolution black-and-white imagery.

jbensman

Thanks.  I THINK everything that I had the problem with was higher than 1 meter resolution. 

maps4gps

Used G-Raster (1.3 from Friday morning download) yesterday on new Oregon 300. 
Worked OK.
Tested USGS 0.3m high res city imagery, NAIP 1 m, 15m ETM, 30M NLCD, and 24K DRG.

Is there any way to set the zoom limits at which the custom map displays on the GPSr?

Are there any general guidelines for which zoom levels the custom maps display at versus the overall image size or the pixel size?

leszekp

AFAIK, there's currently no way to set the zoom limits. G-Raster tells you roughly the maximum zoom level you can get before pixelization sets in (based on GPSFix's chart), and adjusts this based on your rescaling factor.

leszekp

People have reported no problems with resolutions better than 1 meter per pixel, so I don't think that's it. Thought for a second that it might be a problem with grayscale imagery, in that Garmin units might not be able to display grayscale JPGs. But if you had success with the 1-meter black-and-white image, then that's not it.

Don't know what the problem is, then, and without a compatible Garmin unit handy, it'll be hard to debug it. I'm waiting for enough people to register G-Raster at $5 to cover the cost of a compatible unit; at the current registration rate, that may take a while ;-).

Zaphir

Question:  USA Photo Maps shows my area in black and white.  Google Earth shows my area in color.  I would prefer color.  Will G-Raster work with jpgs saved from Google Earth?

Thanks

jbensman

Messed with it some more and still cannot get it to work.  I upgraded to the new firmware and it still does not work.  Has anyone been able to get it to work on higher resoluiotn pictures?  Are there some sucessful ones posted somewhere I could try to see if they work in my GPS.  Thanks

Boyd

Here area bunch that I've created. I used Globalmapper to make these however. Most of them push the limits of Garmin's maximum file size and coverage area: http://www.gpsfiledepot.com/maps/byuser/282/