2003.09.30 14:57 "[Tiff] Reading thumbnail", by takamiyakita@yahoo.co.jp

2003.10.01 12:27 "[Tiff] Reading thumbnail", by takamiyakita@yahoo.co.jp

By reading TIFF Specification, full-size image is in IFD0 and thumbnail is in IFD1.

No, not really. Sometimes a thumbnail gets stored as a second image in the TIFF file. Sometimes there is no thumbnail. Sometimes there is a second image, but it's not a thumbnail version of the first image.

So I'd be careful making assumptions about what you can find in a TIFF file.

Thank you for your advice!!

I confused TIFF with EXIF.

at last, I could get thumbnail data created by Photoshop.

1. I modified libtiff to get the value of tag 34377.
2. I read ID 1033 and 1036 in the data.

more detail, http://partners.adobe.com/asn/developer/pdfs/tn/PhotoshopFileFormats.pdf