On Jul 8, 2008, at 9:27 AM, William Robb wrote: > I was thinking the same thing. All these camera companies have > their own variations on raw > files, be they PEFs or NEFs or whatever. When Adobe released the > DNG format, I thought the idea > was that it would be the file format version of film: IE: a cross > platform format. So what do > the camera makers do? They bugger up the implementation of it. > It's kinda stupid, since Adobe has already done the legwork on > compressed DNG files and all the > camera companies have to do is insert Adobe's compression code into > their own software (it was > released as open source, was it not?).
The Adobe Digital NeGative format specification is not open source: it is publicly disclosed, patented specification with a zero-cost license fee, in perpetuity, much like the TIFF specification. While a subtle distinction, it is important. Here are the information links: http://www.adobe.com/products/dng/ http://www.adobe.com/designcenter/photoshop/articles/phscs2dngspec/ phscs2dngspec.pdf The DNG compression algorithm is encompassed by the specification, but it takes more horsepower to implement than most camera devices are designed with. There are, of course, also always issues with compression/decompression coding which require a great deal of additional testing. For this reason, Adobe recommends device manufacturers to output uncompressed DNG files, minimizing processing power requirements and the possibility of errors in the compression implementation. Handling compressed DNG on a computer should be no difficulty at all, given proper testing. I suspect more that Pentax intentionally does not process DNG files that it does not produce to limit their risks and testing requirements, and perhaps for other marketing reasons. That doesn't make it any less a defective implementation in my view either. Godfrey -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
