Sigma/Foveon Questions
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From: Ray Fischer on 27 Apr 2010 02:42 David J Taylor <david-taylor(a)blueyonder.co.uk> wrote: >"nospam" <nospam(a)nospam.invalid> wrote in message >>> We start with 4Mp of red and blue, we end up with 12Mp of red and blue. >>> Irrespective of what else is used in the interpolation that is *STILL* >>> interpolation and upsizing. >> >> interpolation yes. no upsizing since it's already the correct size. > >Each sensitive element is the same physical size as the resulting RGB >pixel, yes. But the spacing of the pixels is not. For each of the 12M >output pixels, there are only 3M red sensitive locations, at twice the >physical spacing of the 12M pixels. Therefore the red information in >between those red-sensitive pixels is obtained by spatial interpolation. No. No pixels are being added to the image. Additional information is being added to existing pixels. No additional pixels are being added. -- Ray Fischer rfischer(a)sonic.net
From: nospam on 27 Apr 2010 02:48 In article <hr610n$15j$1(a)news.eternal-september.org>, David J Taylor <david-taylor(a)blueyonder.co.uk.invalid> wrote: > "Pixel" may have a number of meanings - there is the element in a JPEG > file which has three components (R, G & B), and there is the region on a > sensor which received light and turns it into an electrical signal. they're all spatial elements of an image. > The > latter are sometimes called sensels, although that's not a term I tend to > use a lot. very few people do, but the number is the same.
From: nospam on 27 Apr 2010 02:50 In article <4bd6875d$0$1616$742ec2ed(a)news.sonic.net>, Ray Fischer <rfischer(a)sonic.net> wrote: > No pixels are being added to the image. Additional information > is being added to existing pixels. No additional pixels are being > added. well put.
From: David J Taylor on 27 Apr 2010 02:50 "nospam" <nospam(a)nospam.invalid> wrote in message news:260420102342027650%nospam(a)nospam.invalid... [] > the spatial location of any given pixel is the same, it's the contents > that is interpolated. think sparse matrix. it's not upsizing a small > 3mp matrix into a bigger 12mp matrix. I prefer to think of the process as spatial interpolation of missing information, as upsizing may have a physical connotation, which could be confusing. Cheers, David
From: Martin Brown on 27 Apr 2010 02:51
Ray Fischer wrote: > Martin Brown <|||newspam|||@nezumi.demon.co.uk> wrote: >> Ray Fischer wrote: >>> Kennedy McEwen <rkm(a)kennedym.demon.co.uk> wrote: >>>> Ray Fischer >>>>> David J Taylor <david-taylor(a)blueyonder.co.uk> wrote: >>>>>> "Ray Fischer" <rfischer(a)sonic.net> wrote in message >>>>>> news:4bd3ec93$0$1610$742ec2ed(a)news.sonic.net... >>>>>>> David J Taylor <david-taylor(a)blueyonder.co.uk> wrote: >>>>>>>>> however, the total number doesn't change. there are 12 million on the >>>>>>>>> sensor and 12 million in the image, or however many the sensor has. >>>>>>>> There are 12 million monochrome pixels on the sensor, >>>>>>> No, there are 4.6 million pixels. Any other claim is a lie. >>>>>>> >>>>>>>> interpolated to 12 >>>>>>>> million colour pixels. The sensor only has 3 million red pixels, but >>>>>>> Learn what "pixel" means. >> I suggest that you learn what a pixel means - that would help. > > You're too much of a stupid ashsole to be condescending. Are you another sock puppet of the P&S troll? > >> The Bayer grid contains filtered photosensor sites. It takes the data >>from several of these to construct any pixel in the final image. > > An outright lie. You are *too* stupid for words. Clueless! I hope that my explanation is clear to anyone who actually wants to learn about the Bayer mask. The final image in a DSLR camera is always RGB format. There might be one somewhere that will do luminance as monochrome but it still requires data from multiple sensor sites to reconstruct that image. > > You're "confused" becuse you think that a pixel must have a certain > amount of color information. In fat it need contain no color information > at all. > >>>>>> This part of the thread had evolved to being about Bayer in a hypothetical >>>>>> 12MP DSLR, and whether or not spatial interpolation was involved. >>>>> A pixel is a picture element. You cannot split up the color >>>>> componenets of a pixel in some arbitrary way and then claim that a >>>>> single pixel is really three, four, or a thousand pixels. >>>>> >>>> So a Bayer CFA sensel, being an incomplete picture element, >>> WRONG. >>> >>> It's not incomplete. There's no such thing as an "incomplete" pixel. >>> A monochrome pixel is still a pixel. >> IA monochrome pixel is a pixel, but only if the image can be interpretted > > Wrong. > > No "if". You really need to go back to basics. Whoever told you what you so fervently believe is completely out of step with imaging conventions. > >> A Bayer mask image looks pretty strange if > > Non sequitur. The definition of pixel has nothing to do with any > sensor type. > >> By any reasonable definition > > You're not reasonable. > >> There are 12M sensor sites, > > Irrelevant. > >> In common computer imaging usage a pixel is generally taken to mean a >> monochrome image of 8, 16 or 32 bits, or a colour pixel with either >> palletted 8 bits, 16bits (R,G,B = 5,6,5), 24bits (8bits for each of >> R,G,B), 48bits (16 bits each for R,G,B). > > LOL! > > Tell us: Where did you get your degree in computer science? Where > did you get your education in computer graphics? I got mine from > Stanford and Cal Poly and from working in the graphics business. You are not a good advert for the quality of their teaching then. Regards, Martin Brown MBCS CEng |