2007.07.05 16:43 "Re: [Tiff] BigTIFF - Aware Aperio version diff", by Joris Van Damme

Kemp,

What are the differences between Aware (official?) and the version Aperio made recently, and any others? It would almost certainly be best to maintain only one version, but has anyone investigated the alternates to ensure the best publicly-available code makes it into the official release?

Fortunately, it's easy to answer your question.

Whilst the Aperio implementation is Aperio's, what you refer to as AWare implementation isn't AWare's. There's no such thing as AWare's LibTiff. I just happen to be the one to do most of the work on the official LibTiff BigTIFF upgrade. Any and all of the work I do in LibTiff is officially approved by the other three LibTiff maintainers, until notice of the contrary, and based on the latest LibTiff version, as I do that work in my capacity as fellow LibTiff maintainer.

As to a comparison of the implementation and the consequences...

Aperio's implementation isn't based on the latest LibTiff version, ours is.

Aperio's implementation does not take into account our future plans for extension of tag/ifd handling, ours does anticipate it. Last but not least, Aperio's implementation is not supported by us. As far as I know, Aperio's and ours both implement the same BigTIFF proposal spec, though we (LibTiff maintainers) had to persuade them to comply as their first draft was substantially incompatible. One final difference, as far as I know, is that Aperio's implementation does not support active selection of version to write, whilst it does support automatic rewriting of a ClassicTIFF file being created as BigTIFF as soon as it hits the size limit. Ours supports active selection of version to write, but does not support automatic rewriting upon hitting size limit (at this time, but we may add support for it later though I believe there are considerable disadvantages to that scheme and to promoting it, both).

Best regards,

Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
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