bildvidgning

Bildvidgning is a term used in Swedish to describe the process of increasing the apparent size of an image or part thereof. It covers both optical magnification achieved with lenses and cameras and digital upscaling applied to raster images.

The concept encompasses optical magnification, where the size of the image is increased by adjusting the optical system, and digital upscaling, where the image is enlarged after capture or creation through processing algorithms. Optical magnification preserves scene detail at the cost of potential changes in perspective and depth, while digital upscaling relies on algorithms to fill in extra pixels.

Digital upscaling is achieved by interpolation methods such as nearest neighbor, bilinear, bicubic, and Lanczos, and in recent years by super-resolution using machine learning. These techniques aim to increase image size while preserving or recovering perceived detail, though none can create true new information beyond the original data in a perfect sense.

Applications include enlarging photographs for printing, improving visibility on displays with limited resolution, and aiding analysis in scientific and medical imaging. Bildvidgning is also used in accessibility contexts to make content easier to view for people with visual impairments, by increasing legibility and perceptual clarity.

Challenges include loss of sharpness, blur, and introduction of artifacts during enlargement, especially with significant upscaling. Digital methods cannot conjure real detail beyond what the original image contains, so the choice of method depends on the intended use, desired quality, and acceptable artifacts.