Digital scan backとは 意味・読み方・使い方

A scanning back is a type of digital camera back. Digital imaging devices typically use a matrix of light-sensitive photosensors, such as CCD or CMOS technologies. These sensors can be arranged in different ways, like a Bayer filter, where each row captures RGB components, or using one full-sized layer for each color, such as the Foveon X3 sensor. The main difference between both approaches is in the way the final image is constructed. In a Bayer filter, since each pixel can only record one color, the resulting pixel has to be constructed with information from its neighbouring pixels using demosaicing algorithms. Using one layer per component instead measures all color components for each pixel, so the resulting pixel is the value measured in every layer for that pixel. This approach delivers better image quality, because all information is actually measured, as opposed to being guessed. The downsides compared to a Bayer filter are that it is much more expensive, because N layers of sensors have to be used, and the resulting digital image is much smaller (by a factor of N). However, since the image is more accurate, more work can be done on it. An image from a Bayer filter is usually downsampled to improve quality, and when upsampling it shows artifacts much faster.