Digitalzoom

When digital zoom is in contrast to a zoom lens, a method based on a mathematical enlarged by a digital camera or a digital camcorder.

Operation

For the image to be stored only a part of the active image sensor surface and thus the optical field of view of the lens is used, which means less pixels are available. The picture is then often extrapolated back to the nominal resolution of the image sensor by the firmware, the missing pixels must be determined from the existing neighboring pixels (see Scaling ( computer graphics) ). In the simplest case this is done by copying a neighboring pixel. By interpolation of several neighboring pixels better results are obtained, the arithmetic and thus time required for the calculation is, however, sometimes considerably higher. This is also in perfect visual illustration of the lens used with a loss of resolution and the associated image quality. The images are blurry or pixelated even with correspondingly enlarged view.

Cameras with a large number of pixels and of good optical quality can with the use of the Image without the subsequent image magnification by the firmware - that is with a reduced number of image points in the saved image - implement a digital zoom. Here, the images are not blurred than the corresponding section of the total intake, but the size of the image area and the number of pixels used in this case is reduced, and this approach does not replace the use of a lens with a longer focal length.

The digital zoom factor is calculated from the ratio of the total available screen size to the screen size actually used.

Under the name of Smart Zoom is a technology is marketed, which works basically the same, and actually represents only one variant in the operation of the camera.