> virtually nobody used the compression method in question and JBIG2 came out around 2000, when the compression issue went public in 2013 it was in widespread

> virtually nobody used the compression method in question and JBIG2 came out around 2000, when the compression issue went public in 2013 it was in widespread use by many Xerox scanners that could scan to PDF and could not be turned off. Of course as non American I have only heard that xerox is synonymous with copying so I might misinterpret the impact the issue had. > b)in the few examples they did, it was quickly found to be harmful, modifying digits and letters. If I understand it correctly the refinement encoding that was exploited in this case would have prevented the replacement issues by storing visible differences along with the glyph replacement. However Xerox did not seem to make use of this feature, resulting in the problematic changes even at the highest quality settings. > you name it. I think Obamas birth certificate was among the victims. Some of the artifacts conspiracy theorists found on available images of it may have been caused by the JBIG2 compression algorithm of a Xerox scanner.