Quote:
Originally Posted by Joe Boy
Some say it is compression artifacts. I just don't know . . . any suggestions??
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Almost certainly JPEG compression artifacts (
Wikipedia).
Quote:
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[...] and/or blockiness in "busy" regions (sometimes called quilting or checkerboarding).
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See
Wikipedia Discrete cosine transform (DCT):
And ponder two-dimensional DCT frequencies:
Somebody was either very sloppy or very deceitful with that Mars image.
Partake of
Bad Astronomer: Are There Artifacts on Mars?