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INPUT CLIP.
The clip to sharpen.
Hint: Start by changing the power value. The larger the radius the slower the effect will be to process.
Radius (Min: 1.0 Max: 20.0 Default: 3.0)
The radius of a circle, around each pixel of the input image, which could be affected by
the sharpening process applied at the input image pixel. If this is set to a very large
value, processing will be slowed noticeably.
The effect on the image of radii much above the default is generally undesirable
(sharpening is most effective when only pixels very close to edges are modified). Large
values may be used for 'special effects', perhaps.
Power (Min: 0.0 Max: 10.0 Default: 0.5)
How strongly edges will be emphasised. Again, values much greater than the default (0.5)
will tend to spoil the sharpened appearance.
PRINCIPLE OF OPERATION
Sharpen uses a simple unsharp masking approach. The input image is filtered at each pixel
with a Gaussian blur kernel (the size of which is controlled by Radius). A fraction of the
low pass filtered image (Power) is then subtracted from the original image to give an
output, which emphasises edges.