[OSM-talk] How to generate a worldfile for an image

[Ralf at Zimmermann.com]

After a few more trying, I found out how to calculate the worldfile.

Here is an example:

---- file.pgw ---------
0.0000122070
0.0000000000
0.0000000000
-0.0000081573
11.6200000000
48.1300000000
-----------------------

Description of the lines:
Line 1: (East-West)/Width_of_Image_in_Pixels
Line 2: Rotation - not used
Line 3: Rotation - not used
Line 4: (North-South)/Height_of_Image_in_Pixels
Line 5: Latitude of upper pixel row
Line 6: Longitude of left pixel column

All values in the file are in degrees.

I checked the worldfile by importing it into TTQV and it works.

RalfZ
Munich, Germany


--- Ralf wrote: -----------------------------

I am looking for practical information on how to create a worldfile
(.pgw) for an image (.png) that I created with osmarender.

I know lat/lon of the four corners of the image and the width/height of
the image. How do I calculate the values for the six lines of the worldfile?

I spent an hour with Google trying to find good information. But I did
not find any practical information how to convert the data.
Now I am confused.

Does anyone on the list have any practical advise on generating a
worldfile with the information I have?

RalfZ
Munich, Germany