Sharp Images and Unsharp Masks

Today, almost all images, from smartphone photos to magazine ads, are algorithmically sharpened, redefining aesthetic standards and altering our perception of what constitutes a “good” image. Sharp is the visual default of everyday photographic culture. This article explores the genealogy of unsharp masking, a method for enhancing images popularized by Adobe Photoshop. Originally developed as an “analog” technique to prevent loss of information in reproducing high-contrast originals, unsharp masking has shifted from preserving details to increasing acutance—i.e., perceived sharpness. This transition reflects its transformation from a specialized tool in fields like X-ray medicine and astrophotography to a universal optimization process in the digital image pipeline. Normalized and largely automated, unsharp masking profoundly influences visual culture.