• Pdf -- how to create pixel-only pdfs?

    From Markus Robert Kessler@2:250/1 to All on Sun Aug 16 01:11:53 2020
    Hi all,

    does anyone know how to create a pdf file containing only pixel
    information, and not vector data?

    Reason behind:
    Some neigbours are asking for permission to use my parking space, when I
    am not there, and hence I'd like to email them some pdf with the
    permission to use space number x from date1 to date2.
    They can print the file and put it into their cars.

    But, I don't want anybody to be able to modify starting / ending time
    easily. This can be done in Gimp anyway, of course, but everyone would be aware, that this is criminal.

    Any easy way to convert or export from (Libre / Open) Office?

    Thanks in advance!

    Best regards,

    Markus

    --
    Please reply to group only.
    For private email please use http://www.dipl-ing-kessler.de/email.htm

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  • From Markus Robert Kessler@2:250/1 to All on Sun Aug 16 01:44:16 2020
    On Sun, 16 Aug 2020 00:11:53 +0000 Markus Robert Kessler wrote:

    Hi all,

    does anyone know how to create a pdf file containing only pixel
    information, and not vector data?

    Reason behind:
    Some neigbours are asking for permission to use my parking space, when I
    am not there, and hence I'd like to email them some pdf with the
    permission to use space number x from date1 to date2.
    They can print the file and put it into their cars.

    But, I don't want anybody to be able to modify starting / ending time
    easily. This can be done in Gimp anyway, of course, but everyone would
    be aware, that this is criminal.

    Any easy way to convert or export from (Libre / Open) Office?

    Thanks in advance!

    Best regards,

    Markus


    Hi,

    forgot to mention that

    convert tmp.pdf tmp.png ; convert tmp.png tmp_new.pdf

    indeed eliminates all vector info and creates a true pixel-only pdf, but
    the quality is crappy.

    Other solutions known?

    Best regards,

    Markus


    --
    Please reply to group only.
    For private email please use http://www.dipl-ing-kessler.de/email.htm

    --- MBSE BBS v1.0.7.17 (GNU/Linux-x86_64)
    * Origin: A noiseless patient Spider (2:250/1@fidonet)
  • From William Unruh@2:250/1 to All on Sun Aug 16 01:46:36 2020
    On 2020-08-16, Markus Robert Kessler <dimke.fax@uni.de> wrote:
    Hi all,

    does anyone know how to create a pdf file containing only pixel
    information, and not vector data?

    Pictures in pdf are jpeg. So you could just put in pictures (which are pictures).

    Reason behind:
    Some neigbours are asking for permission to use my parking space, when I
    am not there, and hence I'd like to email them some pdf with the
    permission to use space number x from date1 to date2.
    They can print the file and put it into their cars.



    But, I don't want anybody to be able to modify starting / ending time easily. This can be done in Gimp anyway, of course, but everyone would be aware, that this is criminal.

    And doing it in text is also criminal.
    Have them send you a copy of the signed permission, at which point you
    have the evidence that they got the permissions and the dates.
    But if you do not trust your neighbors why are you giving them
    permission to park?



    Any easy way to convert or export from (Libre / Open) Office?

    Save as png or jpeg and then use convert to make a pdf.


    --- MBSE BBS v1.0.7.17 (GNU/Linux-x86_64)
    * Origin: A noiseless patient Spider (2:250/1@fidonet)
  • From Paul@2:250/1 to All on Sun Aug 16 04:46:33 2020
    Markus Robert Kessler wrote:
    On Sun, 16 Aug 2020 00:11:53 +0000 Markus Robert Kessler wrote:

    Hi all,

    does anyone know how to create a pdf file containing only pixel
    information, and not vector data?

    Reason behind:
    Some neigbours are asking for permission to use my parking space, when I
    am not there, and hence I'd like to email them some pdf with the
    permission to use space number x from date1 to date2.
    They can print the file and put it into their cars.

    But, I don't want anybody to be able to modify starting / ending time
    easily. This can be done in Gimp anyway, of course, but everyone would
    be aware, that this is criminal.

    Any easy way to convert or export from (Libre / Open) Office?

    Thanks in advance!

    Best regards,

    Markus


    Hi,

    forgot to mention that

    convert tmp.pdf tmp.png ; convert tmp.png tmp_new.pdf

    indeed eliminates all vector info and creates a true pixel-only pdf, but
    the quality is crappy.

    OK, why not pass in a resolution parameter and a page size ?

    The resolution parameter goes in the *first* command.

    The page size declaration goes in the *second* command.

    convert -density 600 dog.pdf dog.png

    convert -page 612x792 dog.png bitdog.pdf <=== Oh, well. This is NOT going to work.
    The Imagemagick forum shows they
    don't have a clue over there.
    Jaggy city.

    dog.png ==> LO-writer insert image, ExportAsPDF ==> bitdog.pdf seems to work...

    Pull dog.png into a new LO Writer document,
    with letter size paper, "Export As" to PDF,
    and then that's the bitdog.pdf .

    When you use a desktop publishing tool, it takes
    the 5100x6600 dog.png and places every pixel into
    the 512x792 Letter page. This requires having a scale
    factor applied to the image inside LO. When the
    page is exported in a WYSIWYG fashion, the right
    thing happens, the jaggies will be reduced compared
    to how Imagemagick was doing it. Like this:

    Here is bitdog.pdf zoomed in, to show the density
    setting is making a difference. And if you set it
    too high, the printer may run out of RAM during
    the page print.

    https://i.postimg.cc/VNZv1605/LO-writer-works.jpg

    Paul

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    * Origin: A noiseless patient Spider (2:250/1@fidonet)
  • From William Unruh@2:250/1 to All on Sun Aug 16 23:01:24 2020
    On 2020-08-16, Markus Robert Kessler <dimke.fax@uni.de> wrote:
    On Sun, 16 Aug 2020 00:11:53 +0000 Markus Robert Kessler wrote:

    Hi all,

    does anyone know how to create a pdf file containing only pixel
    information, and not vector data?

    Reason behind:
    Some neigbours are asking for permission to use my parking space, when I
    am not there, and hence I'd like to email them some pdf with the
    permission to use space number x from date1 to date2.
    They can print the file and put it into their cars.

    But, I don't want anybody to be able to modify starting / ending time
    easily. This can be done in Gimp anyway, of course, but everyone would
    be aware, that this is criminal.

    Any easy way to convert or export from (Libre / Open) Office?

    Thanks in advance!

    Best regards,

    Markus


    Hi,

    forgot to mention that

    convert tmp.pdf tmp.png ; convert tmp.png tmp_new.pdf

    You probably need to tell convert to use a higher pixel/inch setting
    than the default.


    indeed eliminates all vector info and creates a true pixel-only pdf, but
    the quality is crappy.

    Other solutions known?

    Best regards,

    Markus



    --- MBSE BBS v1.0.7.17 (GNU/Linux-x86_64)
    * Origin: A noiseless patient Spider (2:250/1@fidonet)
  • From Daniel65@2:250/1 to All on Mon Aug 17 12:23:45 2020
    William Unruh wrote on 16/08/2020 10:46 AM:

    <Snip>

    And doing it in text is also criminal.
    Have them send you a copy of the signed permission, at which point you
    have the evidence that they got the permissions and the dates.
    But if you do not trust your neighbors why are you giving them
    permission to park?

    William, I'm reading Markus' problem as him not only giving Tenant-1 permission but then also wanting Tenant-1 to be able to show Tenant-2,
    etc, that he, Tenant-1, has Markus' permission to park in Markus' spot!
    --
    Daniel

    --- MBSE BBS v1.0.7.17 (GNU/Linux-x86_64)
    * Origin: A noiseless patient Spider (2:250/1@fidonet)
  • From William Unruh@2:250/1 to All on Mon Aug 17 19:33:39 2020
    On 2020-08-17, Daniel65 <daniel47@eternal-september.org> wrote:
    William Unruh wrote on 16/08/2020 10:46 AM:

    <Snip>

    And doing it in text is also criminal.
    Have them send you a copy of the signed permission, at which point you
    have the evidence that they got the permissions and the dates.
    But if you do not trust your neighbors why are you giving them
    permission to park?

    William, I'm reading Markus' problem as him not only giving Tenant-1 permission but then also wanting Tenant-1 to be able to show Tenant-2,
    etc, that he, Tenant-1, has Markus' permission to park in Markus' spot!

    Yes, but then Tenant-1 can print out the PDF file saved from Libreoffice Writer to show them. His concern is that Tenant-1 might alter the dates
    in the PDF file and print out a document which allows Tenant-1 to part
    there at other times as well. It is that skulduggery which He seems to
    want to prevent by making the PDF be a bitmap rather than a text based
    PDF. And it was his concern about the Tenant-1's intent that he is
    (pretty ineffectively as he admits) trying to make more difficult to
    impliment. There would seem to be two things which he might concern
    him: One is that Tenant-1 parks there (with an altered permission
    document) when (the OP) has given permission to Tenant-2 (or the OPs
    mother) to park there,
    Two is that Tenant-1 alters the document to park there when the OP is
    home and wants to park there.

    If he suspects Tenant-1 to do these things, it is a bit unclear why he
    would allow Tenant-1 to use the spot at all. And Tenant-1 could just manufacture a permission out of whole cloth in those cases anyway.

    If it becomes a matter of calling in an outside referee (Strata Council, Police, the courts) then having a copy signed by Tenant-1 agreeing to
    the dates would seem to be what is needed. Or just making sure that
    Tenant-1 is trustworthy in the first place.


    --- MBSE BBS v1.0.7.17 (GNU/Linux-x86_64)
    * Origin: A noiseless patient Spider (2:250/1@fidonet)
  • From Daniel65@2:250/1 to All on Wed Aug 19 08:06:46 2020
    William Unruh wrote on 18/08/2020 4:33 AM:
    On 2020-08-17, Daniel65 <daniel47@eternal-september.org> wrote:
    William Unruh wrote on 16/08/2020 10:46 AM:

    <Snip>

    And doing it in text is also criminal.
    Have them send you a copy of the signed permission, at which point you
    have the evidence that they got the permissions and the dates.
    But if you do not trust your neighbors why are you giving them
    permission to park?

    William, I'm reading Markus' problem as him not only giving Tenant-1
    permission but then also wanting Tenant-1 to be able to show Tenant-2,
    etc, that he, Tenant-1, has Markus' permission to park in Markus' spot!

    Yes, but then Tenant-1 can print out the PDF file saved from Libreoffice Writer to show them. His concern is that Tenant-1 might alter the dates
    in the PDF file and print out a document which allows Tenant-1 to part
    there at other times as well. It is that skulduggery which He seems to
    want to prevent by making the PDF be a bitmap rather than a text based
    PDF. And it was his concern about the Tenant-1's intent that he is
    (pretty ineffectively as he admits) trying to make more difficult to impliment. There would seem to be two things which he might concern
    him: One is that Tenant-1 parks there (with an altered permission
    document) when (the OP) has given permission to Tenant-2 (or the OPs
    mother) to park there,
    Two is that Tenant-1 alters the document to park there when the OP is
    home and wants to park there.

    If he suspects Tenant-1 to do these things, it is a bit unclear why he
    would allow Tenant-1 to use the spot at all. And Tenant-1 could just manufacture a permission out of whole cloth in those cases anyway.

    If it becomes a matter of calling in an outside referee (Strata Council, Police, the courts) then having a copy signed by Tenant-1 agreeing to
    the dates would seem to be what is needed. Or just making sure that
    Tenant-1 is trustworthy in the first place.

    I suppose your last line is where I'm coming from ... If I can't trust
    the guy to do the right thing, why would I help out in the first place!
    --
    Daniel

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