The unsharp mask is a popular image editing technique used to enhance the sharpness of photographs. Despite its name, it actually sharpens images by increasing contrast along the edges. This is achieved by creating a blurred version of the original image and subtracting it from the original, which highlights the edges and makes them appear more defined. This method is commonly found in software like Adobe Photoshop and GIMP. The unsharp mask has three main parameters: the amount of sharpening, the radius of the effect, and the threshold, which controls how much of the image is affected. Adjusting these settings allows for precise control over the sharpening effect.