I have many (around 1000) multiple-page PDFs for a program I am writing.
The problem is that many of them are inconsistent about page size, even within the same document at times. Does anyone know of a way I could programmatically go through the files and resize the pages to what I want? This can be in any language.
I can accomplish this in Adobe Acrobat Pro, but there are so many that would end up taking a long, long time. The only way I can get it to resize there is to add a background from a file, and then choosing the file i want to resize.
Generally, PDFtk is a good fit for this kind of problems. It will let you pull everything apart, and reorder/resize/modify pages on the command line.
I had a similar problem and could easily solve it with PDF split and merge, a Java based toolkit for editing PDF files.
You can resize a PDF with a command line tool, Ghostscript.
Assuming you want to resize a PDF to 306x396 points (which would give you a quarter of a letter sized pages), do it like this:
gs \
-o 306x396-points.pdf \
-sDEVICE=pdfwrite \
-g3060x3960 \
-dPDFFitPage \
-dUseCropBox \
input.pdf
Note that the -g.... dimensions are in pixels. Because Ghostscript internally computes with 720 PPI by default, these are increased by a factor of 10 as compared to the sizes in points.
For Windows, use gswin32c.exe or gswin64c.exe instead of gs.
Related
I've read a few threads on this general subject, but they don't seem to help so I'm asking as a new question.
I'm currently creating a process to use ghostscript from vb.net (I've had some issues with parameters with Ghostscipt.net, but external process works well enough for me)
I'm capturing a small square area from a specific page of a pdf and converting to a png. There's an offset involved as the area is not on the left/bottom edge, so I'm using 200x200 for the size and -220, 206 for x/y offset and I've specified page 1 for this example, as below:
" -dBATCH -dNOPAUSE -sDEVICE=pnggray -r600 -dDEVICEWIDTHPOINTS=200 -dDEVICEHEIGHTPOINTS=200 -dFIXEDMEDIA -dFirstPage=1 -dLastPage=1 -SOutputFile="mypath\output.png" -c "<</PageOffset [-220 206]>> setpagedevice" -f "mypath\input.pdf"
This works fine, but I next need to restrict the output png file to 600 x 600 pixels, regardless of input size.
All the solutions I've found seem to be related to changing device width/height points, but I use those to specifiy the area I want to capture, so I'm confused as to how this should work.
Can anyone help?
Sorry I couldn't tag this for Ghostscript - my reputation isn't high enough!
Thanks
Thanks K J for your comments, very helpful. I've been testing an alternative library for decoding the QR codes - ZXing.net - and this seems not to be so fussy about resolution and image size, so I think I've gotten around the problem that way.
I've tried it with both 300 and 600 resolution files of different sizes and it's worked well, so I'd recommend it to anyone with this sort of requirement!
I have an old Kindle Dx. Owing to disabilities, I can't use tablets or other touch devices, and I transfer pdfs to the Kindle to read them. It requires pre-processing.
What is a good option to pre-process pdfs without rasterizing them?
[When rasterizing is acceptable:
k2pdfopt -mode copy for maps or for small text. This rasterizes, enhances contrast, and makes everything 1.4-compatible.
k2pdfopt -mode copy -dev dx for other works. This rasterizes to 800x1080, downsamples as needed, enhances contrast while making everything grayscale, and makes everything 1.4-compatible.
When rasterizing text is not acceptable:
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -sstdout=%sstderr -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf if you want to preserve graphics. This makes minimal changes to make everything 1.4 compatible.
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 \
-g800x1080 -r150 -dPDFFitPage \
-dFastWebView -sColorConversionStrategy=RGB \
-dDownsampleColorImages=true -dDownsampleGrayImages=true -dDownsampleMonoImages=true -dColorImageResolution=150 -dGrayImageResolution=150 -dMonoImageResolution=300 -dColorImageDownsampleThreshold=1.0 -dGrayImageDownsampleThreshold=1.0 -dMonoImageDownsampleThreshold=1.0 \
-sstdout=%sstderr -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf if you want moderate downsampling. This re-rasterizes existing raster images to fit 800x1080 and makes everything 1.4 compatible.
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 \
-g800x1080 -r150 -dPDFFitPage \
-dFastWebView -sColorConversionStrategy=Gray \
-dDownsampleColorImages=true -dDownsampleGrayImages=true -dDownsampleMonoImages=true -dColorImageResolution=75 -dGrayImageResolution=75 -dMonoImageResolution=150 -dColorImageDownsampleThreshold=1.0 -dGrayImageDownsampleThreshold=1.0 -dMonoImageDownsampleThreshold=1.0 \
-sstdout=%sstderr -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf if you want more aggressive downsampling. This re-rasterizes raster images to fit 400x540, makes them grayscale, and makes everything 1.4 compatible. Low image quality, but usually still recognizable.
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dFILTERIMAGE -dFILTERVECTOR -sstdout=%sstderr -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf if you want to cut all graphics.
If using any of these options to pre-process for another device check its screen size in pixels. Don't worry too much about pixels per inch.]
[I.S. My goals are to fix pdfs so they 1. don't crash my Kindle, 2. don't freeze my Kindle or take too long to load each page, and 3. don't take up too much of the limited disk space on my Kindle. Preferably also 4. not rasterizing text, 5. not cutting out all images, which can sometimes lose tables, etc. and 6. not reflowing text, which will generally lose tabled. But I'm happy to downsample most images.]
[I.S. Note that I'm keeping copies of the originals. This is not a way to save disk space!]
For scanned pdfs, Willus's k2pdfopt is a great option. I've set up Mac Automator for
k2opt -mode copy -dev dx
or occasionally just -mode copy.
For pdf-born-pdfs, I'd rather not rasterize everything.
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -sstdout=%stderr
-dNOPAUSE -dQUIET -dBATCH
can usually convert files, so the Kindle Dx can open them, but the Kindle will still slow, freeze, or crash with some pages.
One option is to combine Ghostscript and Mutool as follows:
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -sstdout=%stderr -dNOPAUSE -dQUIET -dBATCH to pre-process pdfs to remove passwords,
mutool clean -g -g -d -s -l to sort out the junk, and then
gs
-sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -sstdout=%stderr -dNOPAUSE -dQUIET -dBATCH again to get a smaller and faster pdf.
Note: I think Mutool's 3rd -g is the equivalent of Ghostscript's -dDetectDuplicateImages. Since it slows rendering down it may be better to do the opposite. I'm not sure how to set it to false. -dDetectDuplicateImages false? -uDetectDuplicateImages?
Note: I'm using gtime to time pdf rendering.
A single-step tool in a single application would help. And an image-reduction too would also help. Ghostscript's documentation is hard to follow.
For cleanup, as an alternative to running mutool:
-dFastWebView might help.
-dNOGC indicates that Ghostscript does garbage collection by default.
For image reduction:
-dPDFSETTINGS=/screen seems to work better in 9.50 than 9.23. /ebook might be better since it embeds all fonts.
-dFILTERIMAGE -dFILTERVECTOR also work better in 9.50 than 9.23, but are more drastic than I'd like.
A lot of settings seem to rely in input resolution and/or input page size.
-r seems to rely on input page size, rather than output page size. The Kindle Dx is 800 pixels by 1180 pixels.
-dDownScaleFactor reduces relative to input resolution.
-g800x1080 seems to crop pages, not shrink them.
I think -sDEVICE=pdfimage8 rasterizes everything, like k2pdfopt.
In some cases
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dFastWebView
-uDetectDuplicateImages -dPDFSETTINGS=/ebook -sstdout=%sstderr -dNOPAUSE -dQUIET -dBATCH yields larger and slower files than just -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -sstdout=%sstderr -dNOPAUSE -dQUIET -dBATCH
... I'm not sure what to make of these results.
You've asked an awful lot in here, which makes it rather difficult to read and answer cogently. You haven't really made it clear exactly what it is you want to achieve (you also haven't said what version of GS and MuPDF you are using).
Here are some points;
You don't need to 'clean out the junk' from PDF files produced by Ghostscript, these rarely have anything which can be removed, that's one reason people run PDF files through GS+pdfwrite (despite my saying constantly its a bad idea).
Using the -g switch with Mutool twice doesn't (AFAIK) do anything extra, but adding -d decompresses the files. You can have Ghostscript produce uncompressed PDF files too, use -dCompressPages=false -dCompressFonts=false -dCompressStreams=false.
When you pass your PDF through pdfwrite, then MuPDF, then pdfwrite again, you are risking quality degradation at every step, and the intermediate MUPDF step is unlikely to achieve anything. Most likely what you are doing is reducing the compression (and quality) of any JPEG compressed images, I doubt much else of use is happening.
I can't think why you'd want to not detect duplicate images, it really just makes the file bigger but if you want to you use the switch the same way as all the other GS switches; -dDetectDuplicateImages=false. Note this won't change the processing speed (and generally pdfwrite doesn't do rendering, but perhaps you mean on the target device...), the detection is done by applying an MD5 filter to every image as it is read, then comparing the MD5 hashes. Switching that off doesn't stop the MD5 it just stops the comparison.
If you find Ghostscript's documentation hard to follow, then use the Adobe documentation for distillerparams, that's where the majority of the pdfwrite settings come from (ie blame Adobe for this ;-)
-dFastWebView is (IMO) totally pointless, its there purely for compatibility with Adobe, and because a lot of people won't accept that its useless and insist on it. All it does is speed up loading of the first page of a PDF file, by PDF consumers which support it (which is practically none). And to do this it makes the file slightly bigger and more complicated.
Do NOT use -dNOGC, I keep telling people not to do this, its a debugging tool, it has no practical value in production other than to potentially make Ghostscript use more memory. Everything else you hear about it is cargo cult.
-r has nothing to do with the media szie at all, and does (more or less) nothing with pdfwrite. It sets the resolution of a page when rendering. Since you don't want to render to an image, setting the resolution is not a useful thing to do.
No pdfwrite settings rely on the "input resolution" because PDF (and PostScript) files don't have a resolution, they are vector page descriptions.
-dDownscaleFactor is a switch which only applies to the downscaling devices; tiffscaled and friends, which are rendering devices, it has no effect at all on pdfwrite.
Setting a fixed media size (using -g) does indeed rely on the resolution (because its specified in device pixesl) and does indeed only alter the media size, not the content. If you want to rescale the content to fit the new media, then you need to use -dFitPage. I can't really see why you would do that. Note that it doesn't affect the content of a PDF file (unless its a rendered image), it just makes all the numberic values smaller.
The pdfimage devices do indeed produce a PDF file where the entire content is an image; hence the name....
Now, if you could define what you actually want to achieve, I could make some suggestions.....
[EDIT]
image downsampling
Firstly there are three controls which turn this feature on/off altogether;
-dDownsampleMonoImages, -dDownsampleGrayImages and -dDownsampleColorImages. Assuming you don't select a PDFSETTINGS (I would recommend you do not) these are all initially false. If you want to downsample any images you need to set the relevant mono/gray/color switch to true.
Once downsampling is enabled then you need to set the relevant ImageResolution and DownsamplingThreshold, there are again switches for each colour depth.
Now although PDF files don't have a resolution the images have an effective resolution, but its not easy to calculate (actually without a lot of effort its impossible). Its the number of image samples in the bitmap in each direction, divided by the area of the media covered by the image.
As an example if I have an image 100x100 samples, and that is placed on the page in a 1 inch square, then the resolution of the image is 100 dpi. If I then scale the image up so that it covers 2 inches square (but don't change the image data) then its 50 dpi.
So you need to decide what resolution looks OK on your device. You then set -dColorImageResolution=, -dMonoImageResolution, -dGrayImageResolution.
That's the 'target' resolution. But if the image is already close to that it can be wasteful to process it, so the Downsampling threshold is consulted. The actual resolution of the image in the input has to be the target resolution times the threshold, or more, to be reduced for output.
If we consider, for example, a target resolution of 300 and a threshold of 1.5 then the actual resolution of an image in the input file would have to exceed 450 dpi to be considered for downsampling.
Obviously you can set the threshold to 1.0 eg -dColorImageDownsampleThreshold=1.0
Finally there is the downsampling type, this is the filter used to create the lower resolution image from the higher. The simplest is /Subsample; basically throw away enough lines and columns until we reach the required resolution (this is only filter available for monochrome imsages, as all the others would change the colour depth). Then there's /Average which averages the value in each direction, effectively a bilinear filter. Finally there's /Bicubic which probably does the 'best' job but will be the slowest to process.
On top of all that you can choose the Image Filter (the compression filter) used to write the image data. We don't support JPXEncode in the AGPL version of Ghostscript and pdfwrite. That leaves you /CCITTFaxEncode (for monochrome) DCTEncode (JPEG) and FlateEncode (basically Zip compression). That's MonImageFilter, GrayImageFilter and ColorImageFilter.
If you want to use these you must first set AutoFilterGrayImages to false and/or AutoFilterColorImages to false, because if these are true the pdfwrite device will choose a compression method by looking to see which one compresses most. For Gray and Color images this will almost certainly be JPEG.
Final point is that linework (vector data) cannot be selectively rendered; either everything is rendered or everything is maintained 'as it was'. The only time (in general) that pdfwrite renders content is when transaprecny is present and the output CompatibilityLevel doesn't support transparency (1.3 or below). There are exceptions but they are quite uncommon.
You might want to consider setting the ColorConversionStrategy to either /DeviceRGB or /DeviceGray. I've no idea if you are using colour or grayscale devices, but if they are grayscale creating a gray PDF file would reduce the size and processing significantly. Creating an RGB file for colour devices probably makes sense too, in case the input is CMYK.
I am using (PDF)LaTeX to make a document, and I also need to embed already existing PDF documents in it. The problem is that I have PDF documents in several different page sizes (letter, a4, etc) and I want to compile all of them into a single b5 PDF document.
If I use the pdfpages package from CTAN, all hyperlinks from the original PDFs are removed. So I tried to do it with GhostScript.
This sounds like something normal to do but I have failed to find a working solution.
I have, in the meanwhile, read a few question and answers, but failed to figure out what I am doing wrong and what I am missing.
This doesn't seem to address my problem of scaling.
Neither does that.
This seems to go in the right direction but I couldn't make use of the information :-(.
To make the problem easier, let's just try to resize a single PDF so that:
its contents are scaled to fit the page
the new page has the size I want
Sounds easy, and it is easy to do, for example with pdfjam:
pdfjam --outfile b5-foo.pdf --paper b5paper foo.pdf
Now the problem with this is that pdfjam throws away hyperlinks. From its website:
A potential drawback of pdfjam and other scripts based upon it is that any hyperlinks in the source PDF are lost.
This must be because it seems to use pdfpages mentioned above.
Unlike pdfjam, GhostScript keeps hyperlinks. However, it either:
crops the original when I downscale; or
does not put the scaled content on a page of the size I need -- instead, I get a page that seems to be scaled down, while keeping the original aspect ratio.
This is what I have installed:
$ gs --version
9.21
(Installed on Linux)
This is how I can use GhostScript to crop the content:
gs -dBATCH -dNOPAUSE \
-sDEVICE=pdfwrite -dFIXEDMEDIA -sPAPERSIZE=isob5 \
-o b5-foo.pdf foo.pdf
... and here is how I can use -dPDFFitPage to scale the content but also keep the aspect ratio of the original page size:
gs -dBATCH -dNOPAUSE \
-sDEVICE=pdfwrite -dFIXEDMEDIA -sPAPERSIZE=isob5 -dPDFFitPage \
-o b5-foo.pdf foo.pdf
To be even clearer: I seem to get a page that is scaled so that it would fit inside the b5 I am asking for, but it is not b5: it still has the H/W ratio the original (letter) had!
I'd be happy if this can be done just using switches but if I need to use PostScript that's perfectly fine.
The solution seems to be to use -dPSFitPage instead of -dPDFFitPage. This might have something to do with the PDF files that I am trying to resize. Unfortunately, I cannot share those :-(. When I tried to reproduce this with files that I generated and the problem does not reproduce. I don't know why this is or how I should have known it.
To summarize, using PDF files for both input and output:
-dFitPage and -dPDFFitPage give me scaled pages with the original aspect ratio
-dPSFitPage gives me scaled content on the page size I request with -sPAPERSIZE="$PAPERSIZE"
This seems to go against what the documentation says.
I have a PDF file that I would like to optimize. I am receiving the file from an outside source so I don't have the means to recreate it from the beginning.
When I open the file in Acrobat and query the resources, it says that the fonts in the file take up 90%+ of the space. If I save the file as postscript and then save the postscript file to an optimized PDF, the file is significantly smaller (upwards of 80% smaller) and the fonts are still embedded.
I am trying to recreate these results with ghostscript. I have tried various permutations of options with pswrite and pdfwrite but what happens is when I do the initial conversion from PDF to Postscript, the text gets converted to an image. When I convert back to PDF the font references are gone so I end up with a PDF file that has 'imaged' text rather than actual fonts.
The file contains 22 embedded custom Type1 fonts which I have. I have added the fonts to the ghostscript search path and proved that ghostscript can find them with:
gs \
-I/home/nauc01
-sFONTPATH=/home/nauc01/fonts/Type1 \
-o 3783QP.pdf \
-sDEVICE=pdfwrite \
-g5950x8420 \
-c "200 700 moveto" \
-c "/3783QP findfont 60 scalefont setfont" \
-c "(TESTING !!!!!!) show showpage"
The resulting file has the font correctly embedded.
I have also tried using ghostscript to go from PDF to PDF like this:
gs \
-sDEVICE=pdfwrite \
-sNOPAUSE \
-I/home/nauc01 \
-dBATCH \
-dCompatibilityLevel=1.4 \
-dPDFSETTINGS=/printer \
-CompressFonts=true \
-dSubsetFonts=true \
-sOutputFile=output.pdf \
input.pdf
but the output is usually larger than the input and I can't view the file in anything but ghostscript (adobe reader gives "Object label badly formatted").
I can't provide the original file because they contain confidential information but I will try to answer any questions that need to be answered regarding them.
Any ideas? Thanks in advance.
Don't use pswrite. As you've discovered this will render text. instead use the ps2write device which retains fonts and text.
You don't say which version of Ghostscript you are using but I would recommend you use a recent one.
One point; Ghostscript isn't 'optimising' the PDF the way Acrobat does, its re-creating it. The original PDF is fully interpreted to produce a sequence of operations that mark the page, pdfwrite (and ps2write) then make a new file which only has those operations inside.
If you choose to subset fonts, then only the required glyphs will be included. If the original PDF contains extraneous information (Adobe Illustrator, for example, usually embeds a complete copy of the .ai file) then this will be discarded. This may result in a smaller file, or it may not.
Note that pdfwrite does not support compressed xref and some other later features at present, so some files may well get bigger.
I would personally not go via ps2write, since this just adds another layer of prcoessing and discarding of information. I would just use pdfwrite to create a new PDF file. If you find files for which this does not work (using current code) then you should raise a bug report at http://bugs.ghostscript.com so that someone can address the problem.
You might want to try the Multivalent Compress tool. It has an (experimental) option to subset embedded fonts that might make your PDF much smaller. It also contains a lot of switches that allow for better compression, sometimes at the cost of quality (JPEG compression of bitmaps, for example).
Unfortunately, the most recent version of Multivalent does no longer include the tools. Google for Multivalent20060102.jar, that version still includes them. To run Compress:
java -classpath /path/to/Multivalent20060102.jar tool.pdf.Compress [options] <pdf file>
I need to shrink some large PDFs to print on an 8.5x11 inch (standard letter) page. Can ImageMagick/Ghostscript handle this sort of thing, or am I having so much trouble because I'm using the wrong tool for the job?
Just relying on the 'shrink to page' option in client-side print dialogs is not an option, as we'd like for this to be easy-to-use for the end users.
I would not use convert. It uses Ghostscript in the background, but is much slower. I'd use Ghostscript directly, since it gives me much more direct control (and also some control over settings which are much more difficult to achieve with convert). And for convert to work for PDF-to-PDF conversion you'll have Ghostscript installed anyway:
gs \
-o /path/to/resized.pdf \
-sDEVICE=pdfwrite \
-dPDFFitPage \
-r300x300 \
-g2550x3300 \
/path/to/original.pdf
The problem with using ImageMagick is that you are converting to a raster image format, increasing file size and decreasing quality for any vector elements on your pages.
Multivalent will retain the vector information of the PDF.
Try:
java -cp Multivalent.jar tool.pdf.Impose -dim 1x1 -paper "8.5x11in" myFile.pdf
to create an output file myFile-up.pdf
ImageMagick's mogrify/convert commands will indeed do the job. Stephen Page had just about the right idea, but you do need to set the dpi of the file as well, or you won't get the job done.
Assuming you have a file that's 300 dpi and already the same aspect ratio as 8.5 x 11 the command would be:
// 300dpi x 8.5 -2550, 300dpi x 11 -3300
convert original.pdf -density "300" -resize "2550x3300" resized.pdf
If the aspect ratio is different, then you need to do some slightly trickier cropping.
The Ghostscript approach worked well for me. (I moved my file from my Windows PC to a Linux computer and ran it there.) I made one small change to the Ghostscript command because the Ghostscript resize command above completely fills an 8.5 by 11 inch page. My printer cannot print to the edge, though, so several milllimeters along each page edge were lost. To overcome that problem, I scaled my PDF document to 0.92 of a full 8.5 by 11 inches. That way I saw everything centered on the page and had a slight margin. Because 0.92 * (2550x3300) = (2346x3036), I ran the following Ghostscript command:
gs -sDEVICE=pdfwrite \
-dPDFFitPage \
-r300x300 \
-g2346x3036 \
/home/user/path/original.pdf \
-o /home/user/path/resized.pdf
If you use Insert > Image... in LibreOffice Writer to insert a PDF, you can use direct manipulation or its Image Properties to resize and reposition the PDF, and when you File > Export as... PDF the PDF remains vectors and text. Interestingly when I did this with a PDF invoice the PDF exported from LO is smaller than the original, but the Linux pdfimages command-line utility suggests LO preserves any raster images within the original PDF.
However, you want something easier-to-use for your end users than the print dialog's "Shrink to page" option. There are tools like Adobe Acrobat that lay out PDFs to form print jobs that are PDFs; I don't know which ones have a simple "Change the bounding box and scale to letter-size". Surprisingly the do-it-all qpdf tool lacks this feature.