Scott Auerbach
August 12th, 2006, 09:16 AM
I have no reason to NEED to know this, but inquiring minds, eh?
Is anyone aware of a good, thorough explanation of how pixel shift works? The standard description is that the G CCD is offset compared to the B & R CCDs. But I don't see how that alone would increase resolution any more than offsetting one color printing plate (relative to the others in the CMYK array) would. In fact, it would just look out of register.
I'm assuming there's something more sophisticated going on, and having read a brief description of the physical layout of an interline transfer CCD (something that's not accurately reflected in most diagrammatic illustrations of pixel layout on a CCD, where they're usually explaining the 4:2:2 Bayer layout), I can see how the active pixels could be shifted into the interline area. But that would (seemingly) require that the chip be physically oscillating, which I can't believe it does. The only other option involves some staggered checkerboarding of active pixels and interline areas, with rapid switching between active and inactive areas. But that would mean the G CCD is built to entirely different specs than the other two, and would seem to imply the smaller pixel area that pixel-shifting is designed to avoid.
So... as Ricky Ricardo used to say, "Loooocy, I'm confooooosed."
Anyone have a link to something with good illustrations that explains what's really going on?
Is anyone aware of a good, thorough explanation of how pixel shift works? The standard description is that the G CCD is offset compared to the B & R CCDs. But I don't see how that alone would increase resolution any more than offsetting one color printing plate (relative to the others in the CMYK array) would. In fact, it would just look out of register.
I'm assuming there's something more sophisticated going on, and having read a brief description of the physical layout of an interline transfer CCD (something that's not accurately reflected in most diagrammatic illustrations of pixel layout on a CCD, where they're usually explaining the 4:2:2 Bayer layout), I can see how the active pixels could be shifted into the interline area. But that would (seemingly) require that the chip be physically oscillating, which I can't believe it does. The only other option involves some staggered checkerboarding of active pixels and interline areas, with rapid switching between active and inactive areas. But that would mean the G CCD is built to entirely different specs than the other two, and would seem to imply the smaller pixel area that pixel-shifting is designed to avoid.
So... as Ricky Ricardo used to say, "Loooocy, I'm confooooosed."
Anyone have a link to something with good illustrations that explains what's really going on?