1. A method performed by a computing device for restoring an original spot within a filtered image frame having pixels with values, the filtered image frame having an original un-restored spot of pixels, the filtered image frame being generated by applying a filter to an image frame, the method comprising: identifying a restoration criterion based on the values of the pixels of the original spot; designating by the computing device that the pixels of the original spot are within an enlarged spot and that pixels in a region adjacent to the original spot that satisfy the restoration criterion are also within the enlarged spot; and setting values of the pixels based on whether the pixels are in the restored spot.