Many poor quality scans contain numerous JPEG artifacts (or lossy data compression) which
are portions of the image where there is a distorted, unusually spotty or otherwise messy appearance. These artifacts
occur during extreme data compression when some of the data is lost during the process because the compressor cannot
reproduce sufficiently the data in the saved (compressed) file. Noisy areas along the edges, smeary regions, loss in
color fidelity, and pixelated areas are some examples of the result which make the image unpleasant to look at and
detract from its appreciable value. Compression artifacts commonly happen, for example, when somewhere along the line
the image was converted from a jpg to another image format like a gif, png, etc.