This tool operates as a true unsharp mask control panel. It provides the classic parameters—Amount, Radius, and Threshold—plus advanced safety features like halo limiters and luminance targeting. It is perfect for pulling details out of a screenshot sharpen digital drawing online, recovering soft focus, or adding mid-tone clarity. No image data is ever uploaded to a server.
Radius and amount
Sharpening works by isolating edges and increasing their local contrast. The Radius determines how wide that edge boost is. Small radii (0.5–1.5px) target fine textures like hair or fabric, while large radii (10–30px) create a broader clarity or presence boost.
Amount scales the intensity of the effect. They work inversely: if you use a wide radius, keep the amount low. If you are targeting micro-details with a small radius, you can push the amount much higher.
Controlling noise
Pushing the effect too hard often amplifies digital noise. Use the Threshold slider to protect flat areas. This parameter forces the algorithm to ignore tiny texture differences—like sensor grain or skin pores—and only apply the contrast boost to defined structural edges.
Halo limits and luminance
Aggressive sharpening often creates harsh white or black rims around high-contrast edges. Lowering the Halo Limit clamps the maximum per-pixel change, keeping the edges clean without sacrificing overall crispness.
Keeping Luminance Mode enabled ensures the algorithm only targets brightness values. This prevents chromatic fringing and keeps the original colors pure.