[Gdal-dev] updates of deflate compressed tiff still broken?

[Vincent Schut]

Frank Warmerdam wrote:

>On 1/30/06, Vincent Schut <schut at sarvision.nl> wrote:
>  
>
>>Frank et al.,
>>
>>I'm trying to generate overviews for a compressed (deflate) tiff, which
>>doesn't work. I remember updating compressed tiff files being broken,
>>either in gdal or in libtiff or both, but has this since never been fixed?
>>    
>>
>
>Vincent,
>
>I'm not too sure what is going wrong still with this.   I was able
>to reproduce the problems with an averaged overview build on my
>test file (http://home.gdal.org/~warmerda/world.tif - converted to
>deflate) but without averaging it worked fine.
>
>Also, I found that addtiffo works fine with averaging, so
>till this is properly fixed, you might want to just use that.
>
>eg.
>
>addtiffo -r average abc.tif 2 4 8 ...
>
>The code should be very similar between gdaladdo and addtiffo
>but apparently there are significant differences.
>
>In the past my assumption has been that these problems related
>to issues in the "statefulness" of some of the libtiff codecs, but
>I'm not too sure of that anymore.
>
>You can file a bug on this if you wish, but I'm not sure when I'll
>get around to digging in deeply.
>
>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
>  
>

Frank,

thanks for the info. I'll try with addtiffo. I already tried with the 
ossim app img2rr but that is very slow... I liked the speed of gdaladdo.

Vincent.