> > Jostein wrote: > > >Rob, > > >Did you get a chance to look at SharpRaw? > > >Cheers, > >Jostein > > I'm using SharpRaw right now. I really like the way it does sharpening. It > does a great job with NO halo! Also when converting it saves *istD images at > 3040x2024. I talked the the developer about this and he said that Pentax > wastes bits on each side which SharpRaw does not. I'm still considering if > I'm going to purchase it. I probably will though. It has a lot of other > features which I have not gotten to yet.
The raw sensor data is, indeed, 3040 x 2024. But both the cameras I know that use this sensor (*istD, D100) only create final images 3008 x 2008. I don't know why; perhaps the Sony sensor specs could explain it. On the other hand, though, it's hard to get 3040 x 2024 without implementing quite a lot of special-case code to deal with edge boundary conditions. A straightforward Bayer interpolation scheme will show edge effects on the two outermost pixels alomg each edge. More sophisticated schemes (such as the ones I have been playing around with) will also need a few more strips before they get into ares free of edge effects - my current favourite needs a couple of extra rows, but some need even more than that. The same is true of many other operations (such as sharpening filters). So it's easy to see why the final image size is smaller than the full raw sensor size - it eliminates any possibility of edge-induced artifacts in the image (while still allowing in-camera algorithms to be simpler). Personally I think 3032 x 2016 is quite attainable with reasonable quality, although I'd probably crop it to a true 3:2 3024 x 2016. I find the choice of 3008 x 2008 hard to explain; it's neither a true 3:2 nor an equal number of pixels trimmed off each edge.
