2000.02.06 01:13 "Re: Microsoft Imaging and Jpeg in TIFF", by Joris Van Damme

I wouldn't trust the M$ Wang Imaging solution for generating JPEG in TIFF.

Yeah, sure, but the whole point of this thread was to explore the possibility of reading these bogus files from our non-bogus software, wasn't it?

Andy, did you come up with a reliable way to read these Wang JPEG embedding TIFFs in the end? I would be very interested in hearing about it if you did.

Andy wrote:
> Do you know where I can find TIFF files with thumbnails as one of the
> SubIFDs or an IFD using the SUBFILETYPE or OSUBFILETYPE or preferably common usages
> of each of these?

In general, I think it is very unfortunate the libtiff publication does not include a complete testpics library, like eg libpng does. I have read many questions for specific TIFF files, and I have asked them frequently myself, too, in many places. These questions are seldom answered - probably because of the very limited number of TIFF's 'in the wild', compared to eg JPEG. The absence of a good and complete testpics library is one of the main reasons for the absence of a good and complete tiff reading implementation in current software, I think. It makes our job implementing *good* TIFF reading even harder than it already is. Somebody should *REALLY* take care of that, it would even make a big difference to the future of the TIFF format!

But as for your question, Andy, sorry, I do not even know if my *limited* testpics collection contains any. I don't understand why you bother with thumbnails anyway, today's processing power is sufficient to simply read the whole file and present your user with a preview from that. You can use a secondary thread to first produce a fast nearest-neighbour resized preview thumbnail, and a second lab-interpolated one afterwards. If you build this thread carefully and design it to be interuptable/restartable as a consequence of user action, there is no need at all to include or use space-wasting thumbail images anymore...

Joris