Effects:
Before
AfterThis filter performs a quick blurring on an image. It adds low-frequency details, and the blur strength could be rather large.
Parameters & Effects:

Before
AfterParameters & Effects:

Before
AfterParameters & Effects:

Before
AfterParameters & Effects:

Before
AfterAs the reverse operation of Blur, the Sharpen filter increases the contrast of neighbor pixels to improve the clarity of an image.
Effects:
Before
AfterParameters & Effects:

Before
After