Seems that some artifacts get the wrong width when rendering. I've tested my way to that the artifact is a stroked line and it seems the stroke width is larger than a single pixel and stroke width might only be applied to how wide a stroke is and the length of the stroke might have a minimal length? Poppler seem to handle this stroke correctly.
----- OFF TOPIC
We do text extraction with PDFBox and use poppler today to extract our images because we had a lot of artifacts earlier but with the tremendous work by the team to solve PDFBOX-3000 issues we are looking into using PDFBox for image rendering. A lot of our examples have even more details than the poppler rendered images.
Great work people.