John Francis wrote: > On Thu, Nov 23, 2006 at 09:15:31PM -0500, Adam Maas wrote: > >>The compression engine is already there, it does the PEF compression. >>It's a matter of implementing it for DNG as well. Thus I expect >>compressed DNG via a software update (Unlike on the older bodies which >>lack a compression engine). >> >>Note that such compression engines are often hardware, in the way of a >>dedicated DSP. >> >>-Adam > > > I don't believe any of the 6MP Pentax bodies has any kind of general > purpose DSP. They may possibly have hardware support for JPEG, but I > find even that unlikely - a good software implementation of the JPEG > compression algorithms running on the embedded processor in the camera > can easily support even the 3fps of the K10D. > > The problem with providing compressed DNG is that Pentax are not free > to choose the compression algorithm in use - they must use precisely > the method laid down in the DNG specifications. That means it's more > than simply putting the PEF compression routines into the DNG support; > they'll have to provide completely different routines. >
John, The embedded processor on the 6MP bodies most likely IS a generic DSP, image processing is a standard application of DSP's. I suspect the K10D has a dedicated compression engine in the form of a specialized DSP (they make these for applications like this). Oh, and Pentax is likely using the DNG compression algorithm with PEF's. As far as I'm aware it is LZW, the unnoficial standard method for TIFF's, which would be a no-brainer for implementation on a TIFF-based format like PEF. -Adam -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
