Schärfefilterung

Schärfefilterung, often translated as sharpening filter or unsharp masking, is a digital image processing technique used to enhance the perceived detail and sharpness of an image. It works by increasing the contrast along edges within an image, making them appear more defined. The process typically involves creating a blurred version of the original image, then subtracting this blurred version from the original. This results in an image where only the edges with significant contrast are amplified, while smoother areas remain relatively unchanged.

The effectiveness of schärfefilterung is controlled by several parameters. The radius determines the width of the edges that will be affected. A larger radius will affect broader edges, while a smaller radius will focus on finer details. The amount, or strength, controls the intensity of the sharpening effect. A higher amount will result in a more pronounced sharpening. A threshold parameter is also often used to prevent sharpening in areas of low contrast, such as smooth gradients or noise, which could otherwise be undesirably amplified.

While schärfefilterung can significantly improve the visual clarity of an image, overuse can lead to undesirable artifacts. These can include halos around edges, increased noise, and an unnatural, "over-sharpened" appearance. Therefore, careful application and adjustment of the parameters are crucial to achieve a natural and pleasing result. It is a common tool in photography and graphic design software.