MRC as an explanation has been around since the LFBC PDF was first release.
In the comments of this ORYR article from 2011
http://obamareleaseyourrecords.blogspot.com/2011/04/associated-press-involved-in-new-obama.html
@Anonymous
The artifacts you see are a result of PDF compression...in this case a kind of Mixed raster compression alrogithm was used. You guys are silly...
April 30, 2011 at 9:35 AM
Also when NBC talks about the JPEG, I believe the reference is to the green background layer. That layer is a JPEG and the other layers are bit maps.
The PDF was created on the Xerox by the Xerox. Then e-mailed to a user who opened it on a Mac in Preview.
“The artifacts you see are a result of PDF compression...in this case a kind of Mixed raster compression alrogithm was used.”
Talk is cheap. It took two years before NBC published a pdf claiming to actually reproduce the many “artifacts”...