mark with small spots; "speckle the wall with tiny yellow spots"
Noise affecting Synthetic Aperture Radar (SAR) images. The noise is created by constructive and destructive interference between the backscattered energy from different portions of the ground surface included in the same pixel of the SAR image. The value of the pixel is thus increased or decreased; the SAR image appears to be covered by randomly scattered bright and dark spots.
Noise in a scanned document. Single randomly generated pixels give the impression of a gray veil. The method of automatically removing speckle is called "despeckle".
A group of black pixels of a defined height and width surrounded by white pixels (or white pixels surrounded by black pixels).