2009.02.17 01:49 "Re: [Tiff] DNG question", by Bob Friesenhahn

On Mon, 16 Feb 2009, Gordon Wetzstein wrote:

Sorry for another newbie question, but I'm trying to read DNG files with libTIFF 3.8.2.

I have converted my Nikon RAW files to DNG using the Adobe DNG converter. dcraw can correctly read the files, so they should be fine. Unfortunately, I cannot access the RAW data in the file from my program.

It is likely possible to access DNG raw data from libtiff, but it may take some studying. In addition to that, you would need to be able to decode that raw data, and apply suitable filtering. This is not an easy task. Maybe it is a year's worth of work for an experienced programmer to achieve functionality, and even then, other existing tools would likely produce more refined output.

It is good to take a look at 'dcraw' from http://www.cybercom.net/~dcoffin/dcraw/ since it knows how to read DNG as well as many other formats such as Nikon RAW.

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