You can use the smoothing filters to reduce the harshness and visual noise in a grayscale image.
If an image contains small details that are noise rather than useful data, you can use the smoothing filters to remove these details. For example, a smoothing filter can improve the appearance of scans of half-toned originals.
There are two types of smoothing filters, Low Pass and Median. For more information, see Lowpass Filtering and Median Filter.
AutoCAD Raster Design toolset uses Single Image Optimization to speed up the editing commands.