Yes, I did this, but not even GIMP recognises such multi-page files. On a related matter, judging from https://linux.die.net/man/3/tiffsetdirectory, there should be a way to not need to tamper with TIFFTAG_SUBIFD, i.e. using TIFFReadDirectory sequentially. In fact, it was the approach we were using up to now.
That brings me a few questions to mind: - Does anyone know if that's the intended use of TIFFReadDirectory? If so, wasn't the function intended to seek into the next directory on its own? - Alternatively, are we supposed to use TIFFSetSubdirectory before each TIFFReadDirectory? (getting the offsets with TIFFGetField) Best, amyspark On 09/12/2022 10:52, [email protected] wrote: > Hello amyspark, > > My understanding is that you set the magic TIFFTAG_SUBIFD tag on a > directory with an $n element array of offsets, all initialized to 0, > and then the next $n TIFF directories you write will appear as > subdirectories of this directory, with the offsets filled in for you. > > Or that's what I did here and it seems to work for me: > > https://github.com/libvips/libvips/blob/master/libvips/foreign/vips2tiff.c#L2127-L2141 > > John > > On Fri, 9 Dec 2022 at 12:26, <[email protected]> wrote: >> >> The page I followed when implementing TIFF subframe writing is: >> >> https://stackoverflow.com/questions/11959617/in-a-tiff-create-a-sub-ifd-with-thumbnail-libtiff >> >> HTH >> Paavo >> >> >> -----Original Message----- >> From: Tiff <[email protected]> On Behalf Of L. E. Segovia via Tiff >> Sent: reede, 9. detsember 2022 03:29 >> To: [email protected] >> Subject: [Tiff] How to write multi-file TIFFs >> >> Hi all, >> >> I'm writing to ask about how to create a TIFF with multiple sub-images. >> Our writing code at Krita is unable to create this kind of files, creation >> fails with these lines logged: >> >>> krita.file: "TIFFLinkDirectory: Error fetching directory count" >>> krita.file: "TIFFRewriteDirectory: Error fetching directory count" >> >> A breakpoint on the TIFF error writing routine shows that both are issued >> the moment I call TIFFWriteDirectory for the second and further layers. >> TIFFCreateDirectory, which I saw suggested in tif_overview.c, does not have >> an effect here. >> >> Does anyone know the correct incantations to create this kind of files? >> I'm running LibTiff 4.4.0 at present. >> >> Best, >> >> amyspark >> >> -- >> amyspark 🌸 https://www.amyspark.me >> _______________________________________________ >> Tiff mailing list >> [email protected] >> https://lists.osgeo.org/mailman/listinfo/tiff >> >> _______________________________________________ >> Tiff mailing list >> [email protected] >> https://lists.osgeo.org/mailman/listinfo/tiff > _______________________________________________ > Tiff mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/tiff -- amyspark 🌸 https://www.amyspark.me _______________________________________________ Tiff mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/tiff
