Since 2010 I have been scanning documents and creating pdfs from them
before shredding them.

Most of them were scanned by a Fujitsu cut-sheet feeder.
I had to use Fujitsu's software but that only runs under Windows XP.

I have had too retain a virtual XP ever since.

Today I had to trace back through the pdfs to uncover some information.

Some I could but others refused to open with the Mint Document Viewer.

Naturally I turned to Google. Most suggestions were useless but I hoped
that xpdf mught turn out to be a winner. Not in Mint's repository. :(

Next I tried opening one file in LibreOffice writer and it did! :)

But it was the only one. :(

Is there anyone that has cracked this?

TIA

--
Mint 20.3, kernel 5.4.0-122-generic, Cinnamon 5.2.7
running on an AMD Phenom II X4 Black edition processor with 16GB of
DRAM.

pinnerite wrote:
> Some I could but others refused to open with the Mint Document Viewer.

That viewer is xreader which is a Cinn fork of eye of Gnome.

I don't know the answer to your problem, but I used hexdump on a couple
of .pdf/s I had lying around. Alternatively one could do about all I
did w/ that w/ the xed text reader which will show the first few chars
of the .pdf. Mine start w/ '%PDF-1.5' (no quote).

I don't know how yours start; but you might look at that first part to
compare the ones that open w/ the ones that don't to see if there is
something wrong in that little bit.

--
Mike Easter

On 25/07/2022 19:19, pinnerite wrote:
> Since 2010 I have been scanning documents and creating pdfs from them
> before shredding them.
>
> Most of them were scanned by a Fujitsu cut-sheet feeder.
> I had to use Fujitsu's software but that only runs under Windows XP.
>
> I have had too retain a virtual XP ever since.
>
> Today I had to trace back through the pdfs to uncover some information.
>
> Some I could but others refused to open with the Mint Document Viewer.
>
> Naturally I turned to Google. Most suggestions were useless but I hoped
> that xpdf mught turn out to be a winner. Not in Mint's repository. :(

Yes it is! Use the software manager and search for xpdf.

> Next I tried opening one file in LibreOffice writer and it did! :)
>
> But it was the only one. :(

Did you try qpdfview?

> Is there anyone that has cracked this?
>
> TIA

FWIW, I recently had a problem reading a pdf document. It's this one:
<https://ec.europa.eu/info/sites/default/files/about_the_european_commission/eu_budget/factsheet_eca_web_26.10.pdf>
See the top of page 2 and various other places. I found that in Mint
20.3, qpdfview, xpdf, LibreOffice Draw, and Mint's Document Viewer all
had problems, but MuPDF was ok, and so was FireFox's built-in pdf
viewer. I asked others to check, and qpdfview in Gentoo had no problems.
Others had no problems with various pdf viewers in Windows machines. So
pdfs aren't as universal as they are supposed to be.

Last year I also found something about pdfs that I didn't know. I've
often used their "find" facility to look for certain words. As it
happened, I was looking for a certain phrase of a few words. The "find"
function did highlight the phrase, but I noticed the same phrase a few
lines above was not highlighted. This was because it was on two lines.
The "soft return" - or whatever marks a new line in a pdf, interferes
with the find function. None of the pdf readers I used with a search
facility could find a phrase (or even a word split by a hyphen) which
was on two lines.

--

Jeff

On 25/07/2022 19:19, pinnerite wrote:
> Since 2010 I have been scanning documents and creating pdfs from them
> before shredding them.
>
> Most of them were scanned by a Fujitsu cut-sheet feeder.
> I had to use Fujitsu's software but that only runs under Windows XP.
>
> I have had too retain a virtual XP ever since.
>
> Today I had to trace back through the pdfs to uncover some information.
>
> Some I could but others refused to open with the Mint Document Viewer.
>
> Naturally I turned to Google. Most suggestions were useless but I hoped
> that xpdf mught turn out to be a winner. Not in Mint's repository. :(
>
> Next I tried opening one file in LibreOffice writer and it did! :)
>
> But it was the only one. :(
>
> Is there anyone that has cracked this?
>
> TIA
>
>
Have you tried opening these files in Firefox? If they open in FF then
simply "Save as .." pdf file giving a number or letter after the
original name. Effectively, you are recreating a pdf file from pdf file!
The recreated file should open on any latest OS.

Jeff Layman wrote:
> Did you try qpdfview?

I see this in a discussion about problem .pdf/s:

> My tool of choice for checking PDFs is qpdf. qpdf has a --check argument that does well to find problems in PDFs.

In my repo/s (synaptic view), it looks like qpdf and qpdfview are
'distinct'; one's package doesn't include the other.

eg qpdf:
> QPDF is a program that can be used to linearize (web-optimize),
> encrypt (password-protect), decrypt, and inspect PDF files from the
> command-line. It does these and other structural, content-preserving
> transformations on PDF files, reading a PDF file as input and
> creating a new one as output. It also provides many useful
> capabilities to developers of PDF-producing software or for people
> who just want to look at the innards of a PDF file to learn more
> about how they work.
>
> QPDF understands PDF files that use compressed object streams
> (supported by newer PDF applications) and can convert such files into
> those that can be read with older viewers. It can also be used for
> checking PDF files for structural errors, inspecting stream contents,
> or extracting objects from PDF files. QPDF is not PDF content
> creation or viewing software -- it does not have the capability to
> create PDF files from scratch or to display PDF files.
>
> This package includes the command-line qpdf tools. It also contains
> the documentation.

pdfview:
> qpdfview is a simple tabbed document viewer which uses the Poppler library for
> PDF rendering and CUPS for printing and provides a clear and simple Qt
> graphical user interface. Support for the DjVu and PostScript formats can be
> added via plugins.
>
> Current features include:
> - Outline, properties and thumbnail panes
> - Scale, rotate and fit
> - Fullscreen and presentation views
> - Continuous and multi-page layouts
> - Search for text (PDF and DjVu only)
> - Configurable toolbars
> - SyncTeX support (PDF only)
> - Partial annotation support (PDF only, Poppler version 0.20.1 or newer)
> - Partial form support (PDF only)
> - Persistent per-file settings
> - Support for DjVu and PostScript documents via plugins

--
Mike Easter

On 25/07/2022 21:43, Mike Easter wrote:
> Jeff Layman wrote:
>> Did you try qpdfview?
>
> I see this in a discussion about problem .pdf/s:
>
>> My tool of choice for checking PDFs is qpdf. qpdf has a --check argument that does well to find problems in PDFs.
>
> In my repo/s (synaptic view), it looks like qpdf and qpdfview are
> 'distinct'; one's package doesn't include the other.

It seems to me that the only thing they have in common are the letters
"qpdf"!

--

Jeff

Jeff Layman wrote:
> Mike Easter wrote:
>> Jeff Layman wrote:
>>> Did you try qpdfview?
>>
>> I see this in a discussion about problem .pdf/s:
>>
>>> My tool of choice for checking PDFs is qpdf. qpdf has a --check
>>> argument that does well to find problems in PDFs.
>>
>> In my repo/s (synaptic view), it looks like qpdf and qpdfview are
>> 'distinct'; one's package doesn't include the other.
>
> It seems to me that the only thing they have in common are the letters
> "qpdf"!
>
Yeah; one's a viewer, the other is a serious 'weapon'/tool; and NOT a
viewer per se.

--
Mike Easter

On 7/25/2022 2:19 PM, pinnerite wrote:
> Since 2010 I have been scanning documents and creating pdfs from them
> before shredding them.
>
> Most of them were scanned by a Fujitsu cut-sheet feeder.
> I had to use Fujitsu's software but that only runs under Windows XP.
>
> I have had too retain a virtual XP ever since.
>
> Today I had to trace back through the pdfs to uncover some information.
>
> Some I could but others refused to open with the Mint Document Viewer.
>
> Naturally I turned to Google. Most suggestions were useless but I hoped
> that xpdf mught turn out to be a winner. Not in Mint's repository. :(
>
> Next I tried opening one file in LibreOffice writer and it did! :)
>
> But it was the only one. :(
>
> Is there anyone that has cracked this?
>
> TIA

Do you have backup copies of the file system in question ?

Does the file system throw errors, when this part of the disk is accessed ?

Run the PDF tool in Terminal. Does the PDF tool throw
errors when reading the file ?

Before we had PDF, there was PostScript. It had little in the way
of internal protections. The parser could stop on a damaged structure
and throw a weird error, and you might not be able to guess what
had happened.

The PDF format consists of "Objects", and everything has byte counts.
So at some level, parsing could stop because "this object has too many
bytes or not enough bytes". However, the actual benefit of this
feature is questionable. Because it does not allow us to actually
repair a document.

When we scan to PDF, the PDF adds little in the way of value.
The wrapper is pretty small, consisting of a set of objects that
would be very similar from page to page.

The majority of a page is a JPG or a TIFF, the scanned image.

The scanned image can be at a higher resolution than is
absolutely necessary.

The PDF will say "place this oversize image on an A4", so we
might have a default scale to use when printing.

But once you strip off the auxiliary structures, it's
really just an image format underneath.

Image formats that are compressed, if a compressed bit gets
corrupted, there is "error multiplication". It may be difficult
for a human to even notice a chunk of the image is missing,
because it's binary looking. But with the byte counter,
there is some slim chance we can notice the underlying
image is "short a few bytes".

*******

I recommend this tool, available in quite a few distros.
It can even do things, like convert a binary PDF into a text
PDF (all except for one line which remains binary). Such transformations
would only work if the file was corruption free (of course). I
sometimes convert files from binary representation to a text
representation, to study the objects in them easier.

https://mupdf.com/docs/mutool.html

mutool info some.pdf

mutool convert -F pdf -O decompress,clean -o null.pdf native_plant_id.pdf

Ghostscript has also been changed. They wrote the PDF interpreter
in C for speed. But the nature of PDF does not particularly allow
improvements in the handling, so I have my doubts that this
new interpret will help with corruption issues.

https://ghostscript.com/blog/pdfi.html

*******

Use the file command, and see if it says the file is a PDF.

file some.pdf # Does it say PDF, or is it an entirely different type ???

Paul

On 7/25/22 11:19, pinnerite wrote:
> Is there anyone that has cracked this?

Cracked what? What is your question, exactly? Precisely! What is your
question?

On Mon, 25 Jul 2022 19:19:20 -0700
stepore <stepore@be.here.now> wrote:

> On 7/25/22 11:19, pinnerite wrote:
> > Is there anyone that has cracked this?
>
> Cracked what? What is your question, exactly? Precisely! What is your
> question?
>

Read the subject line first.

:(

--
Mint 20.3, kernel 5.4.0-122-generic, Cinnamon 5.2.7
running on an AMD Phenom II X4 Black edition processor with 16GB of DRAM.

I found a good solution on-line. I posdted it to the alt.os.linux.mint newsgroup

Sorry.

--
Mint 20.3, kernel 5.4.0-122-generic, Cinnamon 5.2.7
running on an AMD Phenom II X4 Black edition processor with 16GB of DRAM.

On 7/29/22 11:52, pinnerite wrote:
> On Mon, 25 Jul 2022 19:19:20 -0700
> stepore <stepore@be.here.now> wrote:
>> Cracked what? What is your question, exactly? Precisely! What is your
>> question?
>>
>
> Read the subject line first.

Your subject line isn't a question.
You don't really ask one at all, other than:
"Is there anyone that has cracked this?"

I mean we can infer what you're asking, but we shouldn't have to.

Is your question, how do I open my crazy pdf files?
Or, maybe how do i download xpdf?
Or is it, LibreOffice writer actually works, thank you very much to the
developers, how can I send them a contribution?

Ask a specific question next time. :(

stepore <stepore@be.here.now> writes:
> On 7/29/22 11:52, pinnerite wrote:
>> On Mon, 25 Jul 2022 19:19:20 -0700
>> stepore <stepore@be.here.now> wrote:
>>> Cracked what? What is your question, exactly? Precisely! What is
>>> your question?
>>
>> Read the subject line first.
>
>
> Your subject line isn't a question.
> You don't really ask one at all, other than:
> "Is there anyone that has cracked this?"
>
> I mean we can infer what you're asking, but we shouldn't have to.
>
> Is your question, how do I open my crazy pdf files?
> Or, maybe how do i download xpdf?
> Or is it, LibreOffice writer actually works, thank you very much to
> the developers, how can I send them a contribution?
>
> Ask a specific question next time. :(

It’s pretty obvious, they want to read their unreadable PDF files.

--
https://www.greenend.org.uk/rjk/

On 7/30/22 02:52, Richard Kettlewell wrote:
> It’s pretty obvious, they want to read their unreadable PDF files.
>

They already said they opened them in LibreOffice.

On 7/29/2022 2:54 PM, pinnerite wrote:
> I found a good solution on-line. I posdted it to the alt.os.linux.mint newsgroup
>
> Sorry.
>

For the damaged ones, it would be interesting to look near the
end of the file for info about what tool produced the PDF. For
example, I made a sample PDF in LO Writer, and this is what is
down at the end.

<</Creator<FEFF005700720069007400650072>
W r i t e r

/Producer<FEFF004C0069006200720065004F0066006600690063006500200037002E0033>
L i b r e O f f i c e 7 . 3

At the top of mine it says this about the standards version of PDF used.

%PDF-1.6

Paul

stepore <stepore@be.here.now> writes:
> On 7/30/22 02:52, Richard Kettlewell wrote:
>> It’s pretty obvious, they want to read their unreadable PDF files.
>
> They already said they opened them in LibreOffice.

Not really:
| Next I tried opening one file in LibreOffice writer and it did! :)
|
| But it was the only one. :(

--
https://www.greenend.org.uk/rjk/