[Gdal-dev] multiband overview problems

[Frank Warmerdam]

Gillian Walter wrote:
> Hi,
> 
> Has anyone else been having problems creating multiband overviews using 
> the latest gdaladdo?  On my machine, adding overviews to multiband 
> tiffs, and creating multiband tiff overviews for other formats, seems to 
> corrupt the tiff header info- gdal's open function is choking at this line:
> 
>    if( (poOpenInfo->pabyHeader[0] != 'I' || poOpenInfo->pabyHeader[1] != 
> 'I')
>     && (poOpenInfo->pabyHeader[0] != 'M' || poOpenInfo->pabyHeader[1] != 
> 'M'))
>        return NULL;
> 
> Single band tiffs are fine though.

Gillian,

I have confirmed that overview generation is causing the file header to be
overwritten and have submitted a libtiff bug on the issue for Andrey to
look into.  It seems to be subtly related to changes made in libtiff in
recent months.

   http://bugzilla.remotesensing.org/show_bug.cgi?id=660

Note, I am not sure how long this issue may have been in the code.  It is
possible that releases as far back as GDAL 1.2.1 are affected.  Hopefully
Andrey can update us on the timeline over which things were broken when he
resolves the problem.

I think I need some overview related tests in my test stream.

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent