Creating World files (jgw etc)

[emj]

breaking out relevant posts from old discussion.

@JRA

Yes, it is great. I am only missing one more option: Automaticly generated ESRI world files or something else for simple georeferencing. Of course the bounding box coordinates are already giving enough information for a bit more advanced users to write manually MapInfo .tab files or OziExplorer .map calibration files, but they are not the most widely supported formats.

@emj

So do you know

• where you can read up on how to create them
• which image format does the work for?
• can you use the Projection OSM uses, or will there have to be conversions first?
• how those files work?

I suspect the most interesting thing todo is to make it easier to import into Illustrator and making it easier to manipulate data in 3rd party programs…

@JRA

Here is something about MapInfo and Ozi formats. They both share the same idea of connecting a few pixels in an image to geographical coordinates. In principle the system works with any image format but of course it is not guaranteed what formats client software support. For accurate interpolation both MapInfo and Ozi want to know the name of the projection but I have not found anything suitable for the spherical Mercator used by OSM slippy maps. I have used WGS84 Lat/Lon coordinates instead and they work well at least with small maps I have been playing with.

It was more simple to find some reading about MapInfo tab than about OziExplorer format. Perhaps info@oziexplorer.com would give
information about the latter. About MapInfo tab the following links seem to give some correct information:

http://mitab.maptools.org/
http://testdrive.mapinfo.com/TECHSUPP/MIPROD.NSF/0/a7fe63f2b3842f49852568800062ee6e?OpenDocument
http://free-zg.t-com.hr/gorantt/geo/tfw2tab.htm
http://www.directionsmag.com/mapinfo-l/mif/AppJ.pdf

Here are commented examples of MapInfo .tab and OziExplorer .map files which are giving a working result even the projection settings in both are most propably wrong because I do not know what would be the correct values.

MapInfo tab:

!table
!version 400
!charset Windowsutf8

Definition Table
File “Helsinki.png” name of the correspoinding image file
Type “RASTER”
(24.919740,60.176970) (0,0) Label “Pt 1”, #Coordinates and image pixel values of Ground Control Point number 1
(24.952700,60.176970) (3072,0) Label “Pt 2”,
(24.952700,60.160570) (3072,3072) Label “Pt 3”
CoordSys Earth Projection 1, 104 #MapInfo definitions strings for the projection
Units “degree” #Map units

OziExplorer .map:

OziExplorer Map Data File Version 2.2
Helsinki2 name that OziExplorer will show in a map list
Helsinki2.png name of the corresponding image file
1 ,Map Code,
WGS 84,WGS 84, 0.0000, 0.0000,WGS 84
Reserved 1
Reserved 2
Magnetic Variation,E
Map Projection,Transverse Mercator,PolyCal,No,AutoCalOnly,No,BSBUseWPX,No #Something about projection, obviously wrong?
Point01,xy,0,0,in,deg,60,10.6182,N,24,55.1844,E, grid, image pixel values ans coordinates Ground Control Point number 1
Point02,xy,3072,0,in,deg,60,10.6182,N,24,57.1620,E, grid,
Point03,xy,3072,3072,in,deg,60,09.6342,N,24,57.1620,E, grid,
Point04,xy,0,3072,in,deg,60,09.6342,N,24,55.1844,E, grid,

Projection Setup, 0.000000000, 30.0, 1.000000000, 4500000.0, 0.00, #These last lines are used by OziExplorer software
Map Feature = MF ; Map Comment = MC These follow if they exist
Track File = TF These follow if they exist
Moving Map Parameters = MM? These follow if they exist
MM0,Yes
MMPNUM,4
MMPXY,1,0,0
MMPXY,2,3072,0
MMPXY,3,3072,3072
MMPXY,4,0,3072
MMPLL,1, 24.919740, 60.176970
MMPLL,2, 24.952700, 60.176970
MMPLL,3, 24.952700, 60.160570
MMPLL,4, 24.919740, 60.160570
MM1B, 4.00
MOP,Map Open Position,0,0
IWH,Map Image Width/Height,3072,3072