2013.06.13 15:52 "[Tiff] TIFF Specification Allowance for Multi-Page vs. Reduced Res 2nd IFD", by Douglas Peterson

2013.06.13 17:57 "Re: [Tiff] TIFF Specification Allowance for Multi-Page vs. Reduced Res 2nd IFD", by Joris Van Damme

Douglas,

Our company is having a problem with several software packages reading our TIFFs as multi-page documents.

The best way, in the sense of "most correct" in my humble opinion, is also the best way, in the sense of "most supported" in my experience.

The trick is to use the SubIFDs tag. Ignore the SubFileType tag, it is ancient and never was very good (as readers need to scan past the IFD they want to interpret, just to see if maybe the next IFD might be related). The newer way, most correct and most supported, is to link your thumbnail IFD to your full-size IFD using the SubIFDs tag.

Actually, you could use the SubIFDs tag for many different versions of a same page, including versions with different size and versions with different colorspace and versions with different compression, whatever makes sense to you. The intent is to communicate that your main IFD is sort-off the standard representation, and the SubIFDs are sort-off alternatives that may be more convenient to a reader depending on circumstances.

Best regards,

Joris Van Damme

AWare Systems