The small dots and miscellaneous marks that show up on image pages that were not on the original Most often the result of telephone line noise that occurs during a fax transmission See Despeckle
The technique of recovering the diffraction-limited angular resolution of a telescope by analysis of images obtained using a very high speed camera system to "freeze" the blurring due to atmospheric turbulence
To mark with small spots of a different color from that of the rest of the surface; to variegate with spots of a different color from the ground or surface