The filter draws the empty sections in the image, “restoring” them according to the surrounding image. For the work of the filter it is necessary to supply at the input the mask of the empty areas which it would draw.
This transformation deletes the shortcomings of the image (empty areas which appeared by capturing, for example, from the dust at the lens; damaged areas of photo, etc) with the help of the adjacent areas of the image.As the result of the work of filter the drawn area hardly visible from the rest.
The Radius (inpaintRadius) determines the radius of the area around parts around which the image is built. The more is this parameter — the slower works the filter and the more accurate the empty area is drawn.
Please find more information on settings and the use of filter in the step by step instruction Tutorial on the use of Inpaint image filter.