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One of the progressive coding methodsused in PNG images. Adam7, named after its author, AdamM. Costello, consists of seven distinct passes over the image.Each pass transmits a subset of the pixels in the image.The pass in which each pixel is transmitted is defined byreplicating the following 8-by-8 pattern over the entireimage, starting at the top left: 1 6 4 6 2 6 4 6 7 7 7 7 7 7 7 7 5 6 5 6 5 6 5 6 7 7 7 7 7 7 7 7 3 6 4 6 3 6 4 6 7 7 7 7 7 7 7 7 5 6 5 6 5 6 5 6 7 7 7 7 7 7 7 7