pdffile special: llx, lly, urx, ury options behave differently than with PSfile for cropped graphics

[agrahn]

pdffile special: llx, lly, urx, ury options behave differently than with PSfile for cropped graphics

[agrahn]

Even better: I found out that the correct way to crop PDF pages is to add a /CropBox entry with the new bbox rect coords to the page dictionary and to leave the /MediaBox entry untouched. The lower left coordinates of the then visible area do not get translated to (0,0) by gs. As a result, pdffile behaves as expected when evaluating the provided bbox options. Nothing needs to be changed/fixed.

I updated cropped.pdf accordingly, and typesetting the code example above now produces the desired result. Thus, #231 is indeed a non-issue. 🎉

[mgieseki]

Unfortunately, this seems to be a bit more complicated. As far as I can tell, Ghostscript and probably also mutool transform the page coordinates so that the lower left corner of the MediaBox is always located at (0,0). As a result, clipping to the original MediaBox coordinates given in the PDF can lead to undesired results.
I'll have a look if I can apply additional translations to adapt the behavior of psfile and pdffile. Since I haven't much time at the moment, this might take a few weeks, though.

[agrahn]

I am going to solve this at the TeX level. The dvisvgm.def graphics driver uses the extractbb command to retrieve the file's MediaBox/CropBox coordinates from the PDF and it is easy to perform the translations based on this. So maybe we can close this issue for now.

[mgieseki]

Ok, great. Thank you for taking care of this. One less issue I have to fix. 😃