`image.get_pos()` returns wrong values for images nested in Form XObjects about pypdfium2 HOT 6 CLOSED

Unfortunately I can't really comment on the values returned by get_pos(), we're just forwarding them from FPDFPageObj_GetBounds()...

I acknowledge DPI is a problem, but not really a bug, since pdfium calculates it from pixel size relative to the occupied canvas area, so this is not actually the DPI metadata embedded in the image. The docs for get_metadata() mention this.
While I know it's confusing, that's just how pdfium's API is designed, and we're only providing the bindings.

(Also note, I would have expected people to use one of the package-specific templates for an issue like this, just to have version info available and so on. I plan to clarify point 2 of the checklist as this seems to be unclear.)

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@PasaOpasen Ah, I figured something out. The image seems to be recursively nested in Form XObjects (twice, actually).
Probably that's what confuses pdfium. It much reminds me of https://crbug.com/pdfium/2073
I would hazard a guess that pdfium currently returns dimensions relative to the nearest Form XObject or something.

>>> import pypdfium2 as pdfium
>>> pdf = pdfium.PdfDocument("color_lines_bad.pdf")
>>> pdf
<PdfDocument uuid:9198c957 from '/home/me/Downloads/color_lines_bad.pdf'>
>>> page = pdf[0]
>>> list(page.get_objects(filter=[pdfium.raw.FPDF_PAGEOBJ_IMAGE], max_depth=1))
[]
>>> list(page.get_objects(filter=[pdfium.raw.FPDF_PAGEOBJ_IMAGE], max_depth=2))
[]
>>> list(page.get_objects(filter=[pdfium.raw.FPDF_PAGEOBJ_IMAGE], max_depth=3))
[<PdfImage uuid:0fc6e6e2>]

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I just filed https://bugs.chromium.org/p/pdfium/issues/detail?id=2100 for this.

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Would you mind closing this issue? I don't think we can do much else now except wait for pdfium.

Or do you reckon we should prevent get_pos() calls on nested objects by raising an exception?
However, we'd have to remember removing that again once the pdfium issue is fixed...

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I also checked with FPDFPageObj_GetRotatedBounds(), it effectively returns the same info:
((0.0, 0.0), (981.0, 0.0), (981.0, 1256.25), (0.0, 1256.25))

(If you're confident what pdfium returns is wrong, then feel free to ask about this on pdfium's mailing list or file a pdfium bug report.) - Update: see finding below

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@mara004 thank u!

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