Archived posting to the Leica Users Group, 1999/10/12
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Shawn, Almost all correct. But it takes four (4) physical pixels to represent one (1) image pixel. It's 4:1, not 3:1. So it's worse than many folks think. The reason is that sensors use a Bayer pattern, which takes into account the most prevalent color mix that mother nature gave us. The pixel sequence is: RGRGRGRGRGRGRGRGRGRGRGRG GBGBGBGBGBGBGBGBGBGBGBGB RGRGRGRGRGRGRGRGRGRGRGRG GBGBGBGBGBGBGBGBGBGBGBGB There are two green pixels for every one red and one blue pixel. They are in a quadrant contained in two pixel rows. RG RG RG GB GB GB So real resolution is one quarter of stated resolution. Jim At 12:34 AM 10/13/99 -0400, Shawn London wrote: > >One additional thing to consider here is that while a digital camera can >consider itself a "2 megapixel" camera as many do these days, it is >important to keep in mind that this is the device's CCD pixel density, not >the actual number of pixels in the final image file that it generates. This >is due to the fact that three imaging sensing pixels in a CCD are needed to >determine the color of a single pixel in the final image. The bottom line is >that there is only 1/3 the effective resolution in a CCD that its stated >resolution would suggest. The rest of the data is interpolated to give you >an image file of the stated resolution (i.e. 1800x1600). >