Internet Archive provides their scans in various formats and AA seems to mostly archive a very poor one. I think what you're describing is the result of a post-

Internet Archive provides their scans in various formats and AA seems to mostly archive a very poor one. I think what you're describing is the result of a post-processing step for one of the space-saving derivatives. It's worth looking up the book on the IA and see how it looks there. Very often, I found that it looks excellent on IA, but terrible, borderline unreadable, in the AA copy. The difference is also obvious in the file size. Generally I found the quality of the original scans of books scanned by the IA to be excellent.