Despeckle plug-in provides selectable filters to remove specs, scratches, or other "noise" in an image. The following filters are available:
Non-recursize adaptive median,
Recursive adaptive median.
Using the Despeckle Plug-In:
Figure 1 shows the despeckle 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 Radius control selects the window size used for the filter, from 1 (3x3) to 20 (41x41). Larger values increase the amount of time needed to filter each pixel in the image and can cause blurring.
The Adaptive button selects the adaptive median filter - this filter varies the window size based upon the image content and sometimes improves the clarity of filtered images. The Black Level and White Level controls adjust the levels used by the adaptive filter to adjust the filter radius.