Make ECW search for its georegistration information from MapInfo TAB files

[morb@…]

Similar to how GTiffDataset::OpenOffset can use a MapInfo TAB file to collect georegistration information, a similar process should be made available for ECW. MapInfo 6 itself can do things this way.

I have already patched ecwdataset.cpp for my own use (and it works!), but I have no sense of if my patch breaks any other existing functionality.

In the more general case, a MapInfo TAB file can probably specify georegistration information for any raster file (not just TIFF and ECW), but ECW just happens to be the format that most of my data is in.

My suggestion would be for me to submit my patch as a starting point so that you can make it more robust for general use.

[Jukka Rahkonen]

If you send your patch then perhaps it will be reviewed sooner or later. A simple auxiliary text file for giving GCP based georegistration for any format would be nice indeed. I can imagine that crowd sourced projects for georeferencing huge amounts of scanned maps could have use for such general easily editable format. The MapInfo tab is otherwise simple and clear but I think that because of the way to express the SRS it is unusable.

CoordSys Earth Projection 8, 79, "m", -2, 49, 0.9996012717, 400000, -100000

At minimum EPSG-codes and proj4 stings in CoordSys should be supported as well.

[Jukka Rahkonen]

Closing because I do not believe that a fix comes after ten years wait.