Is there a difference in pdf files if they are scanned in different ways (scan from the ADF and manual scan on 1 sheet)?

Question

Scanning

Hello!
Faced such a situation. You need to upload a scan of the document (80-90 sheets) to the bus.gov.ru website. Naturally, the document was scanned using the automatic document feeder. When uploading to the site, it gives an error that we are trying to upload an empty file. The authorities say that there has always been such a problem and they had to manually scan each sheet, then it loads normally. Question - what's the matter? And most importantly, is it possible to somehow edit a ready-made pdf file scanned from the automatic feeder so as not to re-scan the entire document manually? I tried to google, but either there is no such information, or I google it somehow wrong. Oh, and of course, the file should have been uploaded yesterday.))

Answer 1

There is no difference. The driver receives the picture and sends it to the scanning program. The scanning program doesn't even know where this file came from, let alone how it was scanned. The file, most likely, is either too large and the site displays a curved output of errors, or it is saved in such a way that the system cannot parse it. Try this: open the pdf file, select print and then microsoft print to pdf. Then try uploading a new file, as a rule, this method should solve such problems.

Answer 2

The state site may simply not understand what the scanning program stuffed into this PDF. For example, there may be compression using a non-standard algorithm or TIFF instead of JPEG.
In principle, any PDF "improver/compressor" converter can convert the data so that the state site understands them - in fact, you only need to compress the pictures into a regular JPEG.
Under Windows I don't know any free PDF converters, I don't use them.
Under Linux, there is ps2pdf that does the job just fine.