PDF/A-2B validation misses validation for images with "/Interpolate true"

[rogerk-apryse]

Hello,

I have a document that passes PDF/A-2 validation with veraPDF but when running it through a fairly new version of Acrobat (version 2023.008.20555) PreFlight, we get an error that says, "Interpolate key for image not false (28 matches on 1 page)"

I checked the PDF file and indeed it turns out that it had /Interpolate true dictionary entries for image objects that are masks of other image objects for the first 27 matches, and the 28th match it was an image for a page thumbnail.

I am not sure if this is something that should be fixes in veraPDF so that it catches these cases or, perhaps, veraPDF only checks images that are directly referenced from page content or page resource dictionaries?

Thanks
Roger

[MaximPlusov]

Hi @rogerk-apryse I wonder if you could attach the PDF file you mention in the issue?

[rogerk-apryse]

Hi @MaximPlusov , here's a zip file with two smaller size versions of the file we have, both converted to PDF/A-1B, both pass veraPDF validation, but one opens in Acrobat and the other does not.
pdfa_1b_mask_with_colorspace_test_files.zip

Thanks
Roger

[MaximPlusov]

We added rules for image mask to latest dev version 1.27.85. But both files from pdfa_1b_mask_with_colorspace_test_files.zip still pass veraPDF validation.