how to convert jpg to a georreferenced image

[zharnik]

I have a detailed topogarfic map in either jpg or PDF. would like to use it and looking for a tool to  georreferenced the image

Thanks

[billw]

I don't get on the forum too often, but if you're still wanting to geo-ref your image or for anyone else who wants to scan maps for OruxMaps...  



I convert scans (1200dpi) of my Green Trails maps to Orux with excellent results.  This will work for JPG but not PDF.  

You need 2 programs: OKMap Creator and OruxMaps Desktop.  OKMap Creator will Geo-Reference the JPG and save it as a raster map (there are probably others that would do this as well, but this is what I use).  OruxMaps Desktop will convert the resulting OKMap to OruxMaps format so you can use in the program.



  OK Map Creator:  https://www.okmap.org/en/en_okmapDesktopFeatures.aspx">//https://www.okmap.org/en/en_okmapDesktopFeatures.aspx

  OruxMaps Desktop: https://www.oruxmaps.com/cs/en/more/downloads">//https://www.oruxmaps.com/cs/en/more/downloads





Here are the steps:



Using OK Map Creator:

1.) Open your JPG as a new Raster Map

2.) Under Map Calibration - click Map Setup

3.) Enter a Name for the Map, click Next

4.) Enter the Datum used for your Map Projection (this should be on the map, most of my Green Trails Maps are WGS84-UTM Zone10N)

5.) Then enter 4 Geo References as shown in the link below.  I use UTM coordinates on the GT Maps.  (click 'Add' under Map calibration to create additional reference points).

Carefully locating these points is the key to having an accurate finished map

Use this layout for geo-refs to calibrate: https://1drv.ms/u/s!APjkSOPhnCRNjH4">//https://1drv.ms/u/s!APjkSOPhnCRNjH4

NOTE: This layout yields MUCH better results than just picking 4 corners.  Notice the points are not in a direct line or diagonal with one another.[/list]
6). Click Accept, then SAVE as OkMap



Using OruxMaps Desktop:

1.) Open the OkMap you just created as a Calibration file

      (the Image file, Datum, and GeoRefs should all populate automatically)

2.) Enter The Map Name you want to appear in OruxMaps

3.) Select the directory where you want to store the finished map on your PC

4.) Select 100% jpeg format quality

5.) Check Multilayer and select 50%, 25% & 12.5%

6.) Check Sqlite format

      ('Only otrk2 file' should NOT be checked)

7.) Click Create Map



This will create a folder containing the OruxMaps files.  Copy the folder to your mobile device in the OruxMaps 'Map Files Directory' you've set.



Hope this helps!

[juvan]

Didn't try it but

But according the website OKmap can convert to Oruxmaps format too...

OkMap include a feature to generate automatically compatible Garmin Custom Maps (KMZ format) and maps in OruxMaps format.

[billw]

Didn't try it but

But according the website OKmap can convert to Oruxmaps format too...

OkMap include a feature to generate automatically compatible Garmin Custom Maps (KMZ format) and maps in OruxMaps format.

Thanks, I didn't remember this, so I tested it on a map I've already converted via OruxMaps Desktop... When saving directly from OKMap (v13.12.2) to OruxMaps format you can only get 1 zoom level (17) and the map would not refresh well (ie; it displays many blank tiles until you scroll past and wait).  The same exact map saved first as OKMap then converted using OruxMaps Desktop can have multiple zoom levels (very useful) and has no problems at all refreshing at any zoom.  So, it seems well worth the extra step.