Werner, Could you write me a line or two about these shifts we get? Like: they're going to be some random, non-integer quantity, right? Also, the rasterization that gets performed, is it anti aliased? It would seem that though shifts and changes in the lengths of the staves are "common", small and relatively benign problems, rotations and scales (magnifications) should be considered major disasters, right?
I do like Michael's idea, used for selected tests (saybe maybe 50 to 80% of the tests). Agreed with Werner that there is the issue we don't have such a backend at the moment, although there is a question as to whether a normalizing postprocess on the SVG output might be enough, assuming there is reasonable certainty that SVG and PDF would be identically reliable for regression testing purposes (again, just for the selected tests) Cheers, L