I get this with the attached image, which is page 14 of the file 002710.pdf in
Invoke.java has a comment "TODO: pass page height?".
After changing the code by passing the height (see also rev 1580326), running code in PDPattern.java is called and I get a better image. To see the difference, look at "Sailor springs" and "New Harmony Consolidated". In the "good" image there's a pattern which isn't in the "bad" image.