On Mon, Sep 11, 2006 at 09:08:27AM -0400, Cory Papenfuss wrote: > > IIRC, the *istD not only does not compress RAW files, but also stores > > pixels in 16bits instead of 12, taking up 30% more space than necessary > > in the process. > > > Yes... quite a brain-dead move on Pentax's part.
As I pointed out at the time, this might have been forced on them by the TIFF software they were using (a PEF file, like RAW files from Canon & Nikon, conforms to the overall structure of a TIFF-EP file, so they could have been using a TIFF file I/O package to create it). Strictly speaking packing two 12-bit quantities into three 8-bit bytes isn't allowed for in the TIFF specs, which assume byte alignement for any quantity larger than four bits. It also allowed for easy expansion to 14-bit or 16-bit values, should sensor technology make that practical. As we all know, that hasn't happened (yet), but that's with the benefit of hindsight. Making that call five years ago would have been considerably more difficult; after all, people still thought full-frame sensors might be practical in the short term. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
