[Qgis-user] use raster + GCP points + ?? as data

[Alex Mandel]

On 07/11/2011 10:30 PM, Richard Duivenvoorde wrote:
> Hi all,
> 
> I have these pile of scanned old maps and can georeference them with the
> good working georeferencer plugin in qgis.
> 
> But do NOT want to really warp the image. Why should we want to store
> TWO huge rasters, maybe loosing 'data' contained in the 'original'?
> 
> So my question: is it possible (for Qgis, but preferebly also with other
> tools (wms's) to load data from the original raster, probably
> accompanied with a txt file with GCP points (or maybe some other format
> containing both gcp points and projection/transformation information)?
> 
> Is there some 'common' way for the the world of gis?
> 
> Thanks for any thoughts,
> 
> Richard Duivenvoorde


A world file is the common way. It describes the coordinates of the
corners, how many units per pixel and what skew if any. See the
wikipedia page for details.

I believe the georef plugin can save the a world file for you.

Thanks,
Alex