Systems, methods, and devices for sharpening image data are provided. One example of an image signal processing system includes a YCC processing pipeline that includes luma sharpening logic. The luma sharpening logic may sharpen the luma component while avoiding sharpening some noise. Specifically, a multi-scale unsharp mask filter may obtain unsharp signals by filtering an input luma component, and sharp component determination logic may determine sharp signals representing differences between the unsharp signals and the luma component. Sharp lookup tables may “core” the sharp signals, which may prevent some noise from being sharpened. Output logic may determine a sharpened output luma signal by combining the sharp signals with, for example, luma component or one of the unsharp signals.