batch compress large number of pdf files

hergipotter · 02-08-2022, 09:59 AM

Hello there,

I have a large number (> 200) of comic books in pdf format but they are quite large (~30 to 70 MB) so they take up too much space on my kindle. My idea now was to compress the images inside the pdf a bit so they get smaller in size without losing too much on the quality.
I've searched this forum and read through some threads but didn't find what I was looking for specifically: A (ideally free) tool that takes all the pdf files, applies some level of compression to the images and provides me with the smaller pdf files.
I was looking into some online converters like ilovepdf.com or pdfcompressor.com but they do not provide many options regarding the level of compression and they also don't take many files at once. Same for pdf printers, I want to avoid having to open every single pdf file and print a compressed version manually. Does anyone know a tool that does the same thing to a number of pdf files at once and provides at least some small level of compression options?

Thanks already in advance!

Shohreh · 02-08-2022, 11:19 AM

Try this:

"c:\Program Files\gs\gs9.55.0\bin\gswin32c.exe" -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

https://ghostscript.com/releases/gsdnld.html

hergipotter · 02-09-2022, 04:25 AM

Thanks for your reply. I gave it a try on a file with a size of 78MB. The output was only 2.2MB in size but it was not readable anymore. I tried also other PDFSETTINGS options:

original: 78MB
/screen: 2.2MB, not readable
/ebook: 6.9MB, barely readable
/printer: 78MB, like original

I would be looking for something in between /ebook and /printer. A reduction in size of about 50% would be more than enough but I'm not familiar with ghostscript at all. Maybe you have some tips for me where to look at?

Then in the end I will need to adapt the script to loop over all pdfs in a folder but I think I can manage that.

Shohreh · 02-09-2022, 08:37 AM

I'm not familiar enough with GS, but you could try playing with the "-r" switch:

https://stackoverflow.com/questions/...-when-using-gh

willus · 02-10-2022, 06:51 PM

See this recent post in the k2pdfopt thread.

hergipotter · 02-11-2022, 03:00 AM

Thanks, I will try it.

02-08-2022, 09:59 AM	#1
hergipotter Junior Member Posts: 5 Karma: 10 Join Date: Feb 2022 Device: Kindle Paperwhite 5	batch compress large number of pdf files Hello there, I have a large number (> 200) of comic books in pdf format but they are quite large (~30 to 70 MB) so they take up too much space on my kindle. My idea now was to compress the images inside the pdf a bit so they get smaller in size without losing too much on the quality. I've searched this forum and read through some threads but didn't find what I was looking for specifically: A (ideally free) tool that takes all the pdf files, applies some level of compression to the images and provides me with the smaller pdf files. I was looking into some online converters like ilovepdf.com or pdfcompressor.com but they do not provide many options regarding the level of compression and they also don't take many files at once. Same for pdf printers, I want to avoid having to open every single pdf file and print a compressed version manually. Does anyone know a tool that does the same thing to a number of pdf files at once and provides at least some small level of compression options? Thanks already in advance!

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02-08-2022, 11:19 AM	#2
Shohreh Zealot Posts: 148 Karma: 192898 Join Date: Jan 2016 Device: none	Try this: "c:\Program Files\gs\gs9.55.0\bin\gswin32c.exe" -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf https://ghostscript.com/releases/gsdnld.html

02-09-2022, 04:25 AM	#3
hergipotter Junior Member Posts: 5 Karma: 10 Join Date: Feb 2022 Device: Kindle Paperwhite 5	Thanks for your reply. I gave it a try on a file with a size of 78MB. The output was only 2.2MB in size but it was not readable anymore. I tried also other PDFSETTINGS options: original: 78MB /screen: 2.2MB, not readable /ebook: 6.9MB, barely readable /printer: 78MB, like original I would be looking for something in between /ebook and /printer. A reduction in size of about 50% would be more than enough but I'm not familiar with ghostscript at all. Maybe you have some tips for me where to look at? Then in the end I will need to adapt the script to loop over all pdfs in a folder but I think I can manage that.

02-09-2022, 08:37 AM	#4
Shohreh Zealot Posts: 148 Karma: 192898 Join Date: Jan 2016 Device: none	I'm not familiar enough with GS, but you could try playing with the "-r" switch: https://stackoverflow.com/questions/...-when-using-gh

02-10-2022, 06:51 PM	#5
willus Fuzzball, the purple cat Posts: 1,274 Karma: 11087488 Join Date: Jun 2011 Location: California Device: iPad	See this recent post in the k2pdfopt thread.

02-11-2022, 03:00 AM	#6
hergipotter Junior Member Posts: 5 Karma: 10 Join Date: Feb 2022 Device: Kindle Paperwhite 5	Thanks, I will try it.