Filters
Main Menu: Image >
Filters
Toolbar button: 
Shortcut: Ctrl-Alt-F
Select the desired filter in the filters list to the left and then click either Apply or New.
Click Apply to apply the filter to the active image or click New to open a new image window showing the filter results.
After clicking Apply, if the results are not the desired ones, click Undo to revert the changes in the image below.
Note: When working with DICOM images the Undo button will not be available.
Supports the following filters:
Average
Average More
Blur
Blur More
Gaussian Blur
Low Pass
Smooth
Smooth Circle
Smooth Cone
Smooth Pyramidal
Sharpen
Sharpen More
Unsharp Mask
High Pass
Laplacian
Edge
Prewitt North South
Prewitt South North
Prewitt East West
Prewitt West East
Prewitt Edge
Sobel North South
Sobel South North
Sobel East West
Sobel West East
Sobel Edge
Line Mask Vertical
Line Mask Horizontal
Line Mask
Emboss
Emboss Color
Mosaic
Minimum
Maximum
Max Min
Min Max
Median
Degrain Bright
Degrain Dark
Degrain