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MarjaE · 06-14-2019, 09:25 PM

Hi,

I am looking for options to speed up my pdfs so they load faster on the Kindle Dx and never crash it. I already convert to version 1.4, either using Ghostscript or Willus' k2pdfopt.

I am trying to optimize for compatibility, and then speed, not file size, so jpeg-2000 is not an option.

1. Conversion with Compression, older system

I used to use the following to pre-process some pdfs for older Kindle compatibility. I mostly ran it in Apple's Automator for drag-and-drop w/o extra typing, but that requires different syntax. It had the side effect of compressing images, and sometimes obscuring pages which had been wrong rendered as images:

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

I think I can get milder compression with:

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

based on these instructions, but reversing the polarity: http://www.spoonylife.org/level-3/co...to-1-5-1-6-etc

2. Conversion without Compression

I currently use the following. I mostly run it in Apple's Automator for the same reason, but that requires different syntax. It avoids obscuring pages, but it sometimes leaves a lot of large images which slow down, freeze, or even crash my Kindle Dx:

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

3. Text-Only, unreliable

I also experimented with variations on the following, but it would lose scale on pages and lose real text as well as images:

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dFILTERIMAGE -dFILTERVECTOR -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

4. Conversion with compression, is there a new system?

Current Ghostscript documentation such as "How to use Ghostscript" avoids mentioning -dPDFSETTINGS or listing the options:

https://www.ghostscript.com/doc/current/Use.htm

But they do mention the extremely buggy and even more aggressive -dFILTERIMAGE and -dFILTERVECTOR, so is there some problem with -dPDFSETTINGS where they want to discourage use short of dropping the function...?

And is there another option replacing -dPDFSETTINGS?

06-14-2019, 09:25 PM	#1
MarjaE Guru Posts: 937 Karma: 53902736 Join Date: Jun 2015 Device: multiple	Pdf compression options in Ghostscript? Hi, I am looking for options to speed up my pdfs so they load faster on the Kindle Dx and never crash it. I already convert to version 1.4, either using Ghostscript or Willus' k2pdfopt. I am trying to optimize for compatibility, and then speed, not file size, so jpeg-2000 is not an option. 1. Conversion with Compression, older system I used to use the following to pre-process some pdfs for older Kindle compatibility. I mostly ran it in Apple's Automator for drag-and-drop w/o extra typing, but that requires different syntax. It had the side effect of compressing images, and sometimes obscuring pages which had been wrong rendered as images: gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf I think I can get milder compression with: gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf based on these instructions, but reversing the polarity: http://www.spoonylife.org/level-3/co...to-1-5-1-6-etc 2. Conversion without Compression I currently use the following. I mostly run it in Apple's Automator for the same reason, but that requires different syntax. It avoids obscuring pages, but it sometimes leaves a lot of large images which slow down, freeze, or even crash my Kindle Dx: gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf 3. Text-Only, unreliable I also experimented with variations on the following, but it would lose scale on pages and lose real text as well as images: gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dFILTERIMAGE -dFILTERVECTOR -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf 4. Conversion with compression, is there a new system? Current Ghostscript documentation such as "How to use Ghostscript" avoids mentioning -dPDFSETTINGS or listing the options: https://www.ghostscript.com/doc/current/Use.htm But they do mention the extremely buggy and even more aggressive -dFILTERIMAGE and -dFILTERVECTOR, so is there some problem with -dPDFSETTINGS where they want to discourage use short of dropping the function...? And is there another option replacing -dPDFSETTINGS?