Preserving page dimensions when converting PDF to TIFF with Ghostscript - bash

I'm converting a folder full of print-ready PDFs into 600 dpi TIFFs, using CCITT Group IV compression (bitonal) on the TIFFs (one TIFF per page). My problem is that the PDFs, which begin with a page dimension of 9x6 inches, are converted into 8.5x11 inch TIFFs (5100 x 6600 px at 600 dpi). Here is the command I'm using to convert PDFs to TIFF files (using bash in Mac OS X):
for folder in $(find * -maxdepth 0 -type d ); \
do gs -dBATCH -dNOPAUSE -q -sDEVICE=tiffg4 -r600 "-sOutputFile=$folder/tiff/%04d.tif" "$folder/pdf/$folder.pdf";
done;
Is there a way to preserve the original page dimensions in my output files?
Thanks in advance!

Ghostscript will preserve the media size of the PDF w3hen creating the TIFF files, so if its not what you expected then either its a bug (you don't say which version of GS you are using, so it might be something that's been fixed) or, more likely, the PDF file has a CropBox which is different to the MediaBox. Screen viewers tend to use the CropBox, Ghostscript defaults to using the MediaBox (because it is at heart a printing application).
You can use the -dUseCropBox switch to have Ghostscript use the CropBox instead, if this is the problem. If it isn't I'd need to see a specimen PDF file. Probably the easiest way is to open a bug report at bugs.ghostscript.com where you can attach a file.

Related

Convert RGB pdf to CMYK preserve pdf

I am using ghostscript 9.25 windows.
I am trying to convert RGB pdf to CMYK preserve pdf using following command:
gswin32c.exe
-dSAFER -dBATCH -dNOPAUSE -dNOCACHE -sDEVICE=pdfwrite -sColorConversionStrategy=CMYK -dProcessColorModel=/DeviceCMYK -dAutoFilterColorImages=false -dAutoFilterGrayImages=false -sOutputFile=out.pdf input.pdf
input.pdf file here
https://www.dropbox.com/s/8jfnov526nhb9m9/blank.pdf?dl=0
output.pdf file here
https://www.dropbox.com/s/ftrmm32mmixaxqh/out.pdf?dl=0
but my output becomes light compared adobe output, expected result is it should be dark when i do in adobe CMYK preserve option, i am getting little dark compared to ghostscript output. Am I doing anything wrong?
Should I use any icc profile?
Thanks
You say you are using ImageMagick, yet you give a Ghostscript command line....
I presume that when you say CMYL you mean CMYK.
There is nothing immediately obviously wrong with your command line, but you have given no example file, nor any reason why you expect the result to be 'dark'.
If you want to control the conversion then you will need to supply at least one and possibly up to 4 ICC profiles. You will certainly need a CIE->CMYK Output profile, and you might like to supply ICC profiles for Gray->CIE, RGB->CIE and CMYK->CIE as well, in order to override the default ones Ghostscript is using.
[EDIT]
The problem is nothing to do with colour conversion. Your original file contains nothing except a very large image, which is compressed with the Flate filter (lossless). It looks like this:
You've turned off auto filtering, but you haven't told Ghostscript which compression filter to use for images, so it sticks with the default, which is JPEG (DCT). The image now looks like this:
For the nature of your original image, JPEG (lossy) compression is an outstandingly bad choice. The output image compresses less well, and it loses fidelity. You should change to using Flate compression instead of JPEG for images of this kind.
By the way, the image in your original PDF file was defined in CMYK space already.

ghostscript how to retain pdf size while converting pdf to grayscale

I am using Ghostscript 8.x to convert a pdf to grayscale.I am using the following command:
gs -dNOPAUSE -dBATCH -q -sOutputFile=- -sDEVICE=psgray 2016-12-15-165043474.pdf | ps2pdf - output.pdf
This successfully converts my pdf to grayscale but I lose the original pdfsize. The resulting pdf has a lot of whitespace looks like A4 size.
My input pdf has fixed width of 3cm (height may vary).I want the output pdf to be of same size.
Please suggest.
Don't use the psgray device! This is seriously deprecated and has been removed totally in recent versions of Ghostscript. By using this you are converting the PDF to PostScript and then converting it back to PDF. More steps than you need (with each conversion potentially introducing problems), and that's where you are getting the default media size from.
Simply use the pdfwrite device to do all the work, but you will need a reasonably recent version of Ghostscript to do it. Possibly more recent than the old version you are obviously using currently.
gs -sDEVICE=pdfwrite -sColorConversionStrategy=DeviceGray -sOutputFile=out.pdf input.pdf

GhostScript PDF to PostScript

I have to convert pdf files (created with jasperreports) to postscript.
I'm using ghostscript (Version 9.19) to make the conversion.
The commmand i'm using is:
gswin64c -dNOPAUSE -dBATCH -sDEVICE=ps2write -sOutputFile=file.ps file.pdf
The conversion is done without problem, but when i open the postscript file generated (using GSview 5.0), the top margin is crop by 2-3 cm, and some information to print is lost.
I have changed the device from ps2write to eps2write, used the property -g<width>x<height> with the page size in pixels, but the problem persist.
The file is to be printed in a preformated paper, so i can not use the postscript generated to print.
Can someone help?
Thanks
Its not possible to say with great certainty, but it sounds like the PDF mediaBox is larger than the media you have specified to GSView.
You can try using the -dDEVICEWIDTHPOINTS and -dDEVICEHEIGHTPOINTS along with -dFIXEDMEDIA and -dPDFFitPage, that should allow you to set up a specific media size, override the size in the PDF file and scale the result to fit the specified size.
Perhaps you could post an example PDF file, without that its very hard to comment sensibly.

ghostscript option to make a pdf with flattened images

Is there an option to print a pdf in ghostscript as images?
I can use:
gs -dNOPAUSE -dBATCH -sDEVICE=pngalpha -r300 -sOutputFile=p%03d.png my.pdf
Then use imagemagick to make a pdf out of them with:
convert *.png new.pdf
PDF printers seem to have an option that does the same thing that is a checkbox that says "print as image". I could not find anything in the ghostscript docs that sounded like that was an option. There may be a term for it that I just don't know to look for.
It is kind of hard to explain why you would want to take a pdf document that is text and turn it into a document of images of text that is 4 times the size of the original but that is what I want to do.
Currently the only way to do that would be to start with a PDF which contains transparency operations, and select a CompatibilityLevel of 1.3 or less.
I have an idea to implement this feature, but I have not had time to work on it.
You can do it as a 2-pass approach using Ghostscript to render an image, then using the view* scripts to read the image back into Ghostscript and produce a PDF. No better than using convert of course.

Fit to page size in ghostscript (with a possibly corrupt input)

I'm trying to use ghostscript to convert a .ps file to a series of .png files, largely because I don't have a tolerable ps viewer.
This is the command I've used:
gs -dBATCH -dEPSCrop -dEPSFitPage -sDEVICE=png16m -r300 -dNOPAUSE -sOutputFile=neptune_111115_ob1-2_13pca_boloplots_%d.png neptune_111115_ob1-2_13pca_boloplots.ps
(the .ps file is a multi-page postscript).
The outputs are partly off the page. I'd like the images to fit inside the page.
I can include example files, but they're pretty large - is there any particular part of the .ps file that would be helpful?
My suspicion is that the .ps file is specifying the bounding box incorrectly, but hacking the BB values didn't have any effect. The .ps file is written by IDL (ittvis' Interactive Data Language). I've also tried the above command without the -dEPS* commands without luck.
-dEPSCrop and -dEPSFitPage are mutually exclusive:
One crops the EPS to the BoundingBox specified in the comments.
The other scales up the EPS from the %%BoundingBox specified in the PS file's internal comments to fit the current media.
You can't really use both at the same time.
The file can't be an EPS file anyway, because you can't have multiple pages in an EPS file. So actually neither switch will have any effect (as you've discovered).
Either the PostScript requests a media size using setpage or setpagedevice, or it just uses whatever the currently set media is. My guess is that its just using the current media. Try setting -sPAPERSIZE=a4 and -sPAPERSIZE=letter.
If that works then the program does not request a media size. If it has no effect, then set -dFIXEDMEDIA in addition which will ignore subsequent requests to change the media size.
That should allow you to specify the correct media size, if you don't know what the media size should be then you can use the Ghostscript -sDEVICE=bbox device to find out.
Lastly, Ghostscript has a rudimentary display device which you can use to view the rendered output without first going to a PNG.

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