2007.11.23 18:04 "[Tiff] Custom Tags and TIFFGetField", by Antonio Scuri
I'm using TIFFGetTagListCount and TIFFGetTagListEntry to loop over all the readed custom tags and import them to my own attribute system.
But since _TIFFVGetField is highly tag dependent I had to use the TIFFFieldInfo definition to interpret the tag type and count. I just checked in libTIFF 4.0 from CVS and TIFFFieldInfo is marked as obsolete, but there are no new functions that replace them.
What I need is something like TIFFGetTagListEntryInfo that returns some parameters of the actual tag readed from file like count and type. But I also need field_passcount because _TIFFVGetField number of parameters depend on it.
Also from _TIFFVGetField:
|| tv->count > 1)
It will return an internal pointer instead of copying the data. So another parameter describing this situation is necessary.
Maybe I should implement two new functions that access libTIFF internal data, called TIFFGetCustomFieldInfo(tag,&count,&type) and TIFFGetCustomField(tag,array) with fixed parameters and a pre-allocated array.