[Qgis-user] Editing the world file

[Micha Silver]

On 13/12/2010 09:46, maning sambale wrote:

> Worldfiles does not store CRS information.  It simply provides you:
> pixel units, rotation, x,y coordinate of the center of the upper left
> pixel:
> http://en.wikipedia.org/wiki/World_file
>
> You need to set the coordinate system in the Layer Properties>
> General>  Specify CRS to view the raster in the proper CRS.
>
>
Furthermore, QGIS will ignore a world file for any raster 
that's already geo-referenced in the header of the *.tif file. 
The *.tfw is relevant only if the raster in *not* internally 
georeferenced.

> On Mon, Dec 13, 2010 at 3:37 PM, LeventB<solfallsild at gaia.de>  wrote:
>> Hi there!
>> As i am writing a tutorial for open-source GIS, i want to make students
>> familiar with the world file connected to a *.tif. The goal is to
>> georeference a raster map by editing the *.tfw, which works well in ArcGIS.
>> There, i proceed in the following way:
>>
>> 1. Open the *.tfw with an editor
>> 2. Adjust the coordinates
>> 3. Save the *.tfw
>> 4. Delete the *.aux file
>> 5. Load the map to the canvas
>>
>> Strangely, this procedure doesn't have any effect in QGIS. Even if i delete
>> every related file except from the *.tfw and the *.tif itself, the map will
>> display the same as before. I wonder where QGIS gets the coordinates?
>>
>> Does anyone have an idea?
>>
>> Thanks and have a nice week,
>> Levent
>> --
>> View this message in context: http://osgeo-org.1803224.n2.nabble.com/Editing-the-world-file-tp5829927p5829927.html
>> Sent from the qgis-user mailing list archive at Nabble.com.
>> _______________________________________________
>> Qgis-user mailing list
>> Qgis-user at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/qgis-user
>>
>
>


-- 
Micha Silver
http://www.surfaces.co.il/
Arava Development Co.  +972-52-3665918