Archived posting to the Leica Users Group, 1999/08/13
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]This is correct. It takes 4 pixels in the camera, to record one image pixel. The stated resolution of consumer digital cameras must be divided by four to get the "real" resolution. Each row of pixels on the sensor contain only two colors. One row of: RGRGRGRGRGRGRG... and the following row: GBGBGBGBGBGBGB... Then: RGRGRGRGRGRGRG... and GBGBGBGBGBGBGB... so the rows look like this: RGRGRGRG... GBGBGBGB... RGRGRGRG... GBGBGBGB... Draw a square around four pixels: RG GB and you have the four pixels required to make up the single image pixel. As Rob said, one RED, one BLUE, and two GREEN pixels per image pixel. There are variations, but for the most part, the above is true. All brand name consumer CCD cameras that I know of are as I described above. Jim At 12:32 AM 8/14/99 +1000, you wrote: >On 13 Aug 99, at 14:52, Jean-Claude Berger wrote: > >> Hello Erwin, >> >> Could this be a typo? I thought that each pixel was represented by 24 or >> 48 bits. How can 4 pixels represent 1 pixel? >> >> > interpolation. Remember that 4 pixels are needed to record >> > one image >> > pixel. > >Jean-Claude, > >Erwin's comment referred to the capture of images via digital camera. The >capture array in these devices is a regular square matrix ie colour reception >elements are placed in a 2x2 dot matrix, not triplets like on a conventional >CRT. AFAIK the matrix consists of a blue, red and two green sensitive >pixels, since more information in the green band is desirable as green is the >frequency to which human sight is most sensitive and subsequently most >critical. Unfortunately I can't seem to find Jim Brick's (?) excellent post >from >many months ago which outlined the subject. > >Cheers, > >Rob Studdert >HURSTVILLE AUSTRALIA >Tel +61-2-9554-4110 >Fax +61-2-9554-9259 >UTC(GMT) +10 Hours >audiob@ozemail.com.au >http://www.ozemail.com.au/~distudio/pagelist.html