Error: 'Can not read TIFF directory count'

Adam Goode adam at
Thu Jul 25 18:40:38 EDT 2013

This problem in libtiff is tracked in

On Thu, Jul 25, 2013 at 5:16 PM, Benjamin Gilbert <bgilbert at> wrote:
> On 07/25/2013 04:11 PM, Tim McIver wrote:
>> I'm using OpenSlide in a csharp project via P/Invoke.  It works fine for
>> the most part but on a particular Aperio slide data file I get an error
>> dialog box that states: 'Can not read TIFF directory count'.  Note that
>> this file /may/ be corrupt in some way.  I attempted catch this error by
>> wrapping the OpenSlide calls in a try/catch but this did not prevent the
>> dialogs from opening.
>> Can anyone give me any hints as to what might be the problem?
> The dialog box is generated by libtiff's default error handler on
> Windows.  OpenSlide doesn't configure libtiff's error handling because
> there's no API for attaching handlers to an individual TIFF handle; they
> can only be overridden globally.  Since OpenSlide is a library and is
> not the application, the global state isn't ours to modify.
> Are you using binaries from the OpenSlide website?  libtiff has a
> compile-time option to disable the dialog box; we should start using
> that.  This will cause libtiff to write error messages to stderr, just
> as it does on Unix.  I'll try to generate a new build with this change
> in the next few days.
> If you want to *completely* suppress the errors, you'll have to call
> TIFFSetWarningHandler() and TIFFSetErrorHandler() yourself.
> --Benjamin Gilbert
> _______________________________________________
> openslide-users mailing list
> openslide-users at

More information about the openslide-users mailing list