Sharpens the image using a proprietary algorithm that mimics an inductive high-pass filter.
Normal Sharpen
Sharpens the image using the common convolution matrix method with a circular aperture.
Luma Sharpen
Sharpens the luminosity data in the image without sharpening the chroma data. This gives aesthetically pleasing results for photographs.
The sharpening is done using the common convolution matrix method with a circular aperture.
Unsharp Mask
Increases the acutance (apparent sharpness) of the image without increasing noise or blemish. This is achieved by applying a Gaussian blur to a copy of the original image and then comparing it to the original. If the difference is greater than a user-specified threshold setting it is added to the image. The threshold control constrains sharpening to image elements that differ from each other above a certain size threshold, so that sharpening of small image details, such as photographic grain, can be suppressed.
Smart Sharpen
Selectively sharpens the image, applying a higher sharpening factor to edges.