Re: Can multiple scans increase resolution?
Quote:
Originally Posted by
fishbulb
I have a bunch of negatives in my scanning queue; I'm going to pick a few to do four 90 degree rotation scans and see what the results are. The rotation may be enough to capture real additional data, regardless of how many pixels are actually moved.
Unless can rotate your negative exactly (and I mean exactly) 90 degrees each time, you will have to rotate something other than 90 degrees in Photoshop to get all the pixels to line up exactly. This will cause interpolation to occur, when you rotate the images, which will nullify any benefits that you hope to achieve.
Re: Can multiple scans increase resolution?
Quote:
Originally Posted by
fishbulb
Outstanding. I'll give this a shot and will report back in a few days.
Thanks,
--Darin
Re: Can multiple scans increase resolution?
There goes a week of experimentation/exploration.
CC will be good to have with some Ram.
:)
Re: Can multiple scans increase resolution?
In theory it works and I am surprised it is not exploited more by cameras with VR features that can dither the image/sensor relationship.
It does not have to be controlled motion or registered to the pixel-level precision. It can be random motion (vibration, etc). For real resolution to be harvested, all that is required is that the motion (noise) is of at least one pixel in extent, and falls within a few other fairly generous boundary conditions as to bandwidth etc.
I do this type of thing a lot in other applications. Resolution and bandwidth (or in photo terms, total exposure time) can be traded off according to well established relationships. Roughly, averaging multiple samples is a waste, because more resolution is not obtained by averaging when in fact it is available, and simply adding the samples together (e.g. taking 4 samples and presuming 4 times the resolution) is over optimistic. In theory you want to take N samples, add them, then divide the result by 2^(N-1) e.g. take 4 samples for up to 1 bit of extra resolution or 256 samples for 4 bits more, etc. This is the theoretical limit of how much extra resolution is obtainable for each unit of bandwidth expended. Of course it is possible (noise less than one pixel/LSB, noise of wrong frequency etc) to expend bandwidth and get as little as nothing for it. If there is some way to measure the result e.g. a resolution chart or comparing an image with the real world, this can be done until the cows come home and the final result compared to the ideal. In real world applications it is surprising how close to the ideal you can come, because usually systems have 1 LSB of noise and most natural sources of noise are broadband in nature.
Think about it...with enough time, enough samples, and by moving the camera enough, you can achieve arbitrary resolution with only one pixel, with dire costs in bandwidth, of course.
Re: Can multiple scans increase resolution?
Quote:
Originally Posted by
Greg Miller
Unless can rotate your negative exactly (and I mean exactly) 90 degrees each time, you will have to rotate something other than 90 degrees in Photoshop to get all the pixels to line up exactly. This will cause interpolation to occur, when you rotate the images, which will nullify any benefits that you hope to achieve.
Ah dang I didn't think of that. I'm doing this on a wet mount drum scanner, so exact 90 degree turns won't be remotely possible. A flatbed would be far more likely to be accurate.
In any case, there will likely be some small rotation adjustments when the layers are aligned in Photoshop, but minimizing the rotation needed is definitely ideal.
Quote:
Originally Posted by
BetterSense
In theory it works and I am surprised it is not exploited more by cameras with VRA features that can dither the image/sensor relationship.
Maybe Sinar had a patent on the technology? Olympus just started with the OMD EM5 II very recently. 16MP sensor, eight shots, creates a 40MP jpg or 64MP raw file.
In their next iteration Olympus thinks they can make the camera capture all eight images in under 1/60th of a second, making handheld high-res capture (sort of) possible. In bright light anyway. Eight shots in 1/60th would be 1/500th apiece, assuming no lag between shots.
It would be interesting to see this technology combined with an electronic shutter like in some of the new Fuji cameras, which are capable of up to 1/32000 (yes, 1/32000). But electronic shutters have their own limitations so it still wouldn't be ideal for handheld photography.
Re: Can multiple scans increase resolution?
Can multiple scans increase resolution?
No.
Re: Can multiple scans increase resolution?
Testing in progress. But another question.
Will techniques such as this, in use i the new Olympus camera, "solve" the problem of legacy glass not being up the standards of newer sensors, in terms of resolution?
--Darin
Re: Can multiple scans increase resolution?
Why would it? These techniques effectively act as a higher resolution sensor. If the system is already lens limited, then there shouldn't be an improvement. I'd be happy to be wrong. Older lenses, especially primes, can be outstanding performers, though.
Re: Can multiple scans increase resolution?
Quote:
Originally Posted by
Peter J. De Smidt
Why would it? These techniques effectively act as a higher resolution sensor. If the system is already lens limited, then there shouldn't be an improvement. I'd be happy to be wrong. Older lenses, especially primes, can be outstanding performers, though.
My thinking is--based on nothing!--that you are combining two sharp images, with the final image being the same size as the uncombined version. And wouldn't being pixels vs film matter in this case?
Darin
Re: Can multiple scans increase resolution?
So Bettersense, you are saying that the new Olympus E-M5 I I is a scam?