2006.01.09 15:57 "Re: [Tiff] Multipage 16bit TIFF in Delphi", by Bob Friesenhahn

I have multipage Tiffs with 16 Bit per sample, which I want to read, to manipulate and to save again.I tried it with the example LibTiffDelphiHigherLevel from Joris (February 2005), but the result is only a black image.

I've received your code and testfile.

What you have here, is a problem. You're seeing a black image, because, strictly speaking, it is a black image. Double-check with Photoshop, Irfanview, or any mainstream viewer if you like.

I have encountered a number of TIFFs like this. Usually they are from scientific applications such as from specialized CCD cameras. Or they could be from a remote-sensing application.

In development GraphicsMagick 1.2 there are special provisions for TIFFs which store a bitwise smaller sample in a 16-bit space. So it is possible to tell GraphicsMagick the number of bits which represent the sample so that the data is automatically scaled into visible space.

Bob
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Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/