Sharpen plug-in provides a sharpening filter to enhance the edges in a blurry image.
Using the Sharpen Plug-In
Figure 1 shows the sharpen plug-in window. The scrollbars allow you to pan within the image (in this case to the back of the duck in the foreground). The preview window shows the filter output using the current settings.
The Sharpness control selects the amount of sharpening to apply, from 1 to 99 percent. Higher values make the edges in the image increasing distinct.