I want to use QGIS to do some georeferencing and image registration. On ArcMap10 I can define an "Unknown Projection", basically a default metric grid, and use it as a grid for georeferncing.
In QGIS however, when I tried to georeference an image with GDAL, it gave me the following error:
Failed to compute GCP transform: Transform is not solvable
I've looked around and figured that the problem lies with the projections.
I've imported a 4 line CSV with 4 points demarcating the image extent in meters (BL 0,0, UR 450,450), but the layer properties tell me it's in WGS 84. because I do not know the actual coordinates of the image, I have to use just a basic internally coherent 5*5 metric grid, that I can georeference with corresponding marks in the image. This can only work with a datumless metric projection, which I do not know how to define (and save it as a custom defined projection)
I'm new to QGIS, so the problem might be remarkably easy to solve, but after a few hours of searching, I still haven't found it.
appreciate any help, H.