[Gdal-dev] Adding Projection to ECW files ?

[Bill Binko]

On Mon, 20 Jun 2005, Frank Warmerdam wrote:

> On 6/19/05, Bill Binko <bill at binko.net> wrote:
> > 
> > Hi everyone: I hope everyone enjoyed the conference.  If anyone has time
> > to look at this, I'd really appreciate it.  I really would like to be busy
> > making summary layers, but am stuck at this point.
> 
> Bill, 
> 
> Sorry for the delay in responding.  As always there are various
> ways of approaching this.   Ideally at the point you were
> generating the ECW file you would have set the coordinate system.
> Something like this (assuming WGS84):
> 
> gdal_translate -of ECW -a_srs '+proj=utm +zone=17 +datum=WGS84' in.tif out.ecw
> 

I knew you were busy with the conference: this is important to me, but not 
critical.  Unfortunately, I got the ECWs rather than the TIFFs, so I can't 
re-compress them.  I considered using gdal_translate from ECW to ECW, but 
was worried that I might lose fidelity.

> Assuming you don't want to regenerate the ECWs you should be able to push
> the georeferencing into the PAM file (.aux.xml) with a small python script. 
> 

Is that PAM file documented anywhere?  I can write a script to edit XML if 
I know what I'm writing to.

> I had intended to provide an example of this, but find that I have another bug
> to pursue before I can complete this, but I had better send this email before
> I reboot. 

Understood: I appreciate any help you can give.

Thanks,
Bill