I am using
gs -dBATCH -dNOPAUSE -sDEVICE=pdfwrite -sOutputFile=book.pdf -f front-matter.pdf fulltext-0.pdf fulltext-1.pdf back-matter.pdf
to create a single PDF document from a series of pdf documents. I was going to include a new made-up table of content and include it using the pdfmark mechanism. Then I notice that the original files already have bookmarks in them - they are however referenced to the original page numbers, not the ones in the combined document.
I am looking for two possible solutions. Remove the orginal bookmarks or make use of the original bookmarks but somehow update their page references...
As so often the case, someone has walked the same path before you...
unfolding disasters has worked out a solution to this very problem. His python script pdf-merge.py first invokes pdftk with its dump_data switch to retrieve all the pdfmark information. It then keeps track of the total number of pages for each merged document and does the math to offset the new page number pointer in the pdfmark instruction by the sum total of page counts of all the PDF documents included before the current PDF document. So it is close but not the same as the 2-pass approach of KenS. It first discovers bookmarks using pdftk and then creates a new bookmark file with correct page numbers. It also manages to turn the original pdfmark instruction (that would normally be preserved by gs into noop). I won't pretend I understand how that last part worked ...
However, the script does all I need including the option of tweaking the bookmark file before the final writing. Very neat and hat tip to Trevor King.
In general pdfwrite doesn't know you are appending files, so it preserves bookmark and other 'metadata' information on the assumption that you will want it in the output.
However, when you are combining PDF files, preserving the information won't work, as the page numbers for the second and subsequent files will be incorrect.
So you need a 2-pass approach, first merge all the files, discarding the bookmarks, then 'convert' the merged file and add pdfmarks to set the correct bookmarks.
There is currently no option (with pdfwrite) to not preserve bookmarks. You will need to modify the Ghostscript PDF interpreter PostScript files to achieve this I think. You might try setting -dDOPDFMARKS=false, but I doubt that will work.
Related
I'm using /usr/bin/pdftk filename.pdf dump_data_fields output - flatten to get the FDF fields in a PDF but it seems to be including invisible FDF fields as well.
https://docdro.id/nriB59b is a one-page PDF without any txt but with a number of these invisible FDF fields. pdftk's output can be seen at https://pastebin.com/ag6vweNP.
How can I exclude invisible FDF fields?
I'm currently using pdftk but I'm open to using other tools as well.
Thanks!
My guess is you have to inspect the PDF yourself to detect if or not a field is invisible. In another side, it may become very tricky to tell if a field is invisible or not, except if a flag sets this.
For example, although I don't know if it's possible, but let say a field is outside the page or covered by another content... Is it visible or not?
By the way, you can use qpdf to inspect the content of a PDF file. The following command will decompress your pdf to get it human readable.
qpdf --qdf --object-streams=disable orig.pdf uncompressed-qpdf.pdf
If you prefer a JSON representation:
qpdf --json your_pdf.pdf > your_pdf.json
If you go for the later one, you can parse the json output with jq.
Then, use the PDF speficication you want to apply. I suggest also these steps:
you produce a pdf with a given field visible
another copy of this pdf but with the field hidden
uncompress both of them and then compare them with diff.
When I run a PDF which was originally created with LibreOffice on Linux, through ghostscript 9.19 on OSX, to produce another (flattened) PDF, the output is perfect except for one problem. All emdashes in the entire document have been replaced with a standard hyphen (awkwardly followed by half of a space.) Oddly enough, if I highlight the resulting "hyphen+space", my context menu shows that I've selected an emdash, so the underlying text is still an emdash, it is just rendering the wrong glyph.
I can reproduce this on multiple documents from the same source, and I'm assuming there's a setting or switch somewhere that can help resolve this.
I don't know whether the font used makes a difference, but for the sake of reference, the body text of my document is set in Arno Pro. When I use a modern version of LibreOffice on OS X to make a sample document also containing an emdash in Arno Pro, the same problem is not exhibited, so it seems to be specific to the software which originally made these PDF files.
These PDFs are of legacy projects that I am not set-up to re-produce at this time, so I need to prepare them for reprinting using the existing files.
How do I retain emdash glyphs when running a command such as the following?
gs -dSAFER -dBATCH -dNOPAUSE -dNOCACHE -sDEVICE=pdfwrite \
-sColorConversionStrategy=/LeaveColorUnchanged \
-dAutoFilterColorImages=true -dAutoFilterGrayImages=true \
-sOutputFile=output.pdf input.pdf
I can add an example of the input PDF to this question if needed.
Without seeing the PDF file it isn't possible to give you an answer. Most likely the font isn't embedded, or if it is embedded doesn't have an emdash glyph.
Copy and paste uses the ToUnicode CMap, so it isn't dependent on the font. Its simply a list of character codes and the Unicode code point associated with each, when using a given font.
Note that this doesn't mean 'the underlying text is still an emdash'. The ToUnicode information is utterly separate from the font end of things, it is effectively metadata and bears no real relation to the font or rendering.
Put the file on DropBox and post the URL and someone can look into it. I'll be on vacation for the next few days though, but maybe someone else will look.
Note that in PDF you don't necessarily specify characters and positions as a list of consecutive characters; you can specify the position of each individually, or you can specify widths which override the width in the font, etc. So there almost certainly is only one glyph, the 'white space' you refer to is probably just that, white space, its not another glyph.
I should also point out (I do this a lot) that Ghostscript never 'flattens', concatenates, merges, or anything similar operation on PDF files. WHen using Ghostscript and the pdfwrite device the original input (in whatever format) is fully interpreted into graphics marking operations, and sent tot eh device. The device executes the marking operations; in the case of a rendering device, it scan-converts and writes to a bitmap. In the case of pdfwrite, it creates PDF operators.
The result of this is that the output PDF file bears no relation to the input PDF, other than its visual appearance.
You also don't say which version of Ghostscript you are using....
I was given some really old but very useful hand-written notes recently and in a bid to preserve them, I had them scanned into a file in the PDF format. What I have is a 35 page PDF but I want to add a contents page at the beginning so that I can use the first page to click my way to a specific topic.
More precisely,
I want a page which says
Topic 1
Topic 2
Topic 3
...
Each one should be linked to a page of my choosing.
I've explored a lot of standard tools out there to help me with this, like LibreOffice, pdftk etc. but the solution does not appear to be in the form of a simple application and a few clicks. My hunch is that this will require a program written in a suitable language. The way I'd want this program to work as follows:
ProgramName Input.pdf CustomTOC.txt
Where CustomTOC.txt could be a simple ASCII table containing two columns, one column being the title and the second column being the page number. The output of this program will be another PDF file which contains one page appended at the beginning of Input.pdf containing a table of contents with hyperlinks to the right pages.
I have managed to solve this problem though I don't think this is the best way to do it. I have written a Python program that accepts two mandatory inputs - the input PDF file and '|' separated ASCII table containing columns and page numbers. A third optional output can be the name of a PDF file which contains the output. If this is not provided then the original input file is rewritten.
How the code works? Uses a system call to 'pdftk' for bursting the PDF file into its constituent pages. Writes a .tex file which contains a \listoffigures command for the first page with the package hyperref ensuring it links to the figures. The later part of the .tex code contains several figure insertion statements where the PDF file corresponding to each page is inserted, providing captions only to those PDFs for which there is an entry in the provided TOC table.
Why the code is not ideal? It relies on too many dependencies. It relies on a system call to the pdftk package, it requires that LaTeX be also installed on the machine with the graphics package. In the current version of the code, the PDFs on each page do have some offset which I am trying to solve using geometry package with custom margin settings. I will try to post the code once this problem is solved.
A more ideal solution. That which does not require LaTeX and can use some PDF library within Python to achieve the same effect. Comments and suggestions welcome!
I have a Pdf file which contains several slides per page, including text (not only images).
This pdf was probably created using pdfnup.
Can I revert the pdfnup operation so that each slide is shown on one page?
As far as I know, there is no simple to be used 'undo' operation.
However, the following answers show you the approach principle, how you can achieve the undo-equivalent operation using Ghostscript:
Convert PDF 2 sides per page to 1 side per page (Superuser)
How can I split a PDF's pages down the middle? (Superuser)
Cropping a PDF using Ghostscript 9.01 (Stackoverflow)
PDF - Remove White Margins (Stackoverflow)
(Should these not help you to find the final solution, ask again. But then to come up with a fully working commandline, I'd need the complete output of the following command first: pdfinfo -f 1 -l 100 -box your.pdf.)
This question already has answers here:
Merge / convert multiple PDF files into one PDF [closed]
(23 answers)
Closed 6 years ago.
I have 16 pdfs that I want to convert into a single one... I am on Ubuntu 10.10, how can I do it?
First, get Pdftk:
sudo apt-get install pdftk
Now, as shown on example page, use
pdftk 1.pdf 2.pdf 3.pdf cat output 123.pdf
for merging pdf files into one.
You can also use Ghostscript to merge different PDFs. You can even use it to merge a mix of PDFs, PostScript (PS) and EPS into one single output PDF file:
gs \
-o merged.pdf \
-sDEVICE=pdfwrite \
-dPDFSETTINGS=/prepress \
input_1.pdf \
input_2.pdf \
input_3.eps \
input_4.ps \
input_5.pdf
However, I agree with other answers: for your use case of merging PDF file types only, pdftk may be the best (and certainly fastest) option.
Update:
If processing time is not the main concern, but if the main concern is file size (or a fine-grained control over certain features of the output file), then the Ghostscript way certainly offers more power to you. To highlight a few of the differences:
Ghostscript can 'consolidate' the fonts of the input files which leads to a smaller file size of the output. It also can re-sample images, or scale all pages to a different size, or achieve a controlled color conversion from RGB to CMYK (or vice versa) should you need this (but that will require more CLI options than outlined in above command).
pdftk will just concatenate each file, and will not convert any colors. If each of your 16 input PDFs contains 5 subsetted fonts, the resulting output will contain 80 subsetted fonts. The resulting PDF's size is (nearly exactly) the sum of the input file bytes.
You can use http://www.mergepdf.net/ for example
Or:
PDFTK http://www.pdflabs.com/tools/pdftk-the-pdf-toolkit/
If you are NOT on Ubuntu and you have the same problem (and you wanted to start a new topic on SO and SO suggested to have a look at this question) you can also do it like this:
Things You'll Need:
* Full Version of Adobe Acrobat
Open all the .pdf files you wish to merge. These can be minimized on your desktop as individual tabs.
Pull up what you wish to be the first page of your merged document.
Click the 'Combine Files' icon on the top left portion of the screen.
The 'Combine Files' window that pops up is divided into three sections. The first section is titled, 'Choose the files you wish to combine'. Select the 'Add Open Files' option.
Select the other open .pdf documents on your desktop when prompted.
Rearrange the documents as you wish in the second window, titled, 'Arrange the files in the order you want them to appear in the new PDF'
The final window, titled, 'Choose a file size and conversion setting' allows you to control the size of your merged PDF document. Consider the purpose of your new document. If its to be sent as an e-mail attachment, use a low size setting. If the PDF contains images or is to be used for presentation, choose a high setting. When finished, select 'Next'.
A final choice: choose between either a single PDF document, or a PDF package, which comes with the option of creating a specialized cover sheet. When finished, hit 'Create', and save to your preferred location.
Tips & Warnings
Double check the PDF documents prior to merging to make sure all pertinent information is included. Its much easier to re-create a single PDF page than a multi-page document.
There are lots of free tools that can do this.
I use PDFTK (a open source cross-platform command-line tool) for things like that.
Also seem pdfjam: http://www2.warwick.ac.uk/fac/sci/statistics/staff/academic/firth/software/pdfjam/