Adobe Acrobat Pro provides preflight profiles for testing whether a PDF file conforms to any of PDF/A or PDF/X standards. There are also options for converting a non-compliant PDF file to any one of those standards if such fixups are possible.

FYI, there are specifications for the different PDF/A and PDF/X specifications that you may purchase (either hardcopy or downloadable PDF files) from ISO.

          - Dov

Another trick in Acrobat Pro is to invoke the Output Preview tool (under “print production”) and choose the Object Inspector instead of the Separations function. Then click on a particular image. You will see what type of compression is used, the image resolution, the color space (including ICC profile if appropriate), etc. That same tool also shows what font a text is formatted in and point size as well as attributes of other PDF objects as well. It is exceptionally useful in determining what you have in a PDF file.

If you want to look at everything at once, under Preflight, pull down Options and invoke Create Inventory. That function will create a monstrous PDF detailing all the objects and features of the PDF file in question!

          - Dov

For better or worse, ISO specifications are written in a language from a parallel universe.    After dealing with ISO standards for a while, you learn what specific words really mean. I should know - I am chair of the ISO PDF/X task force and co-chair of the PDF/VT task force.

The word should does not specify a requirement. PDF/A does not prohibit lossy compression.

JPEG is always a lossy compression. There is a mode of JPEG2000 compression that is indeed lossless. Note that JPEG and JPEG2000 are totally different compression schemes. (I believe that PDF/A-1 as well as PDF/X-1a and PDF/X-3, based on older versions of the PDF specification do not permit JPEG2000. PDF/A-2 based on ISO32000-1 and PDF/X-4 based on PDF 1.6 do allow for JPEG2000.)

ZIP compression is lossless.

          - Dov

As PDF/A-2 has only been a standard for about 6 months now, I am not aware of any scanners that are producing PDF/A-2.  However, the only advantage of PDF/A-2 for scanning – which is important – is support for JPEG2000.