How to compress pdf file which contains high resolution images.

[rupeshforu3]

Hi I am Rupesh from India and I have an android tablet and an Acrobat reader and a PDF file. I have tried to open it in Acrobat reader and failed to load even after 10 minutes but I have copied the above file to PC and tried to open it in Acrobat reader and it has been successfully loaded.

I have extracted the images of the above pdf file to 427 jpeg files. Surprisingly the resulted folder size is 1.2 GB and the PDF file size is 54 mb only. After that I have seen the properties of one jpeg file and it is 3.5 mb with 2048\* resolution.

I think that the tablet consists of processor with lower resources and the system processor has higher resources. So the above mentioned pdf file is unable to load in the tablet.

I have opened a number of pdf files in my tablet and everything worked fine except this.*

I have tried to compress the pdf file using ghost script guis like densify and workerpdf using options like ebook, screen, pre press etc.,. and unfortunately all of the resulting output files are above 150 mb.

After that I have compressed the 427 jpeg files using ffmpeg gui tool called format factory and the resulted folder size is 250 mb. I have even created pdf using a tool called ilovepdf by selecting all of the compressed jpeg files. Unfortunately the resulted output pdf file is 250 mb.*

Can anyone of you suggest how to compress the pdf file by internally compressing the images present in the pdf file.*

Regards
Rupesh.

[jhowell]

You could split the PDF into two or more files each with a subset of pages.

[rupeshforu3]

I have tried to convert and compress pdf file in various apps like ghost script, Nitro pdf, Acrobat reader dc etc.,.

Unfortunately all the resulted pdf files are greater than 150 mb.

After that I have copied resulted pdf files to my Lenovo tab and fortunately all are working on my tablet.

Sent from my LM-G710 using Tapatalk

[Critteranne]

Adobe has a tool that lets you compress PDFs for free online. But you will have to save the file to the Adobe Document Cloud and agree to terms of use, etc.

https://www.adobe.com/acrobat/online/compress-pdf.html

With Adobe Pro, the Optimize feature might work, but that costs a lot of money. I think even the free version of Adobe Acrobat DC doesn't have free compression.

Gizmo's Best suggests some free PDF tools, including software that does compression:
https://www.techsupportalert.com/bes...ght=compressor

[willus]

Originally Posted by rupeshforu3

Can anyone of you suggest how to compress the pdf file by internally compressing the images present in the pdf file.

It is unclear what will give you the best reading experience on your tablet and/or what you want to do. I'm guessing the issue is that your PDF uses JPX compression which is notoriously CPU intensive to render. In that case, simply converting to JPEG or Flate compressions may be all you need, but it will make the file much larger, as you have discovered.

Did you want to actually change the resolution of the PDF images in your document so that they have fewer pixels? You can use k2pdfopt to do that:

k2pdfopt myfile.pdf -mode copy -dpi 200 -o outfile.pdf
(This will change every page of your PDF to a bitmap image at 200 dpi but will retain text searchability if your document has text.)

You can adjust the dpi to whatever suits you. 200 is usually reasonable. This will default to Flate compression (aka PNG). If you want to use JPEG compression instead of PNG, you can add this option:

-jpg <quality> (where quality = 1 to 100 specifies the JPEG quality)

You can use k2pdfopt with the -i option to see what compression is being used on the images in your PDF (or from the GUI, select "PDF File Info" from the help menu).

[Quoth]

Also try Xodo to read pdfs on Android. I've used it on several Lenovo and slow generic tablets with huge files. I have a 256 G SD card.

[rupeshforu3]

I have opened the pdf file in k2pdfopt and after that I have seen the properties of the file and it is showing images as jpx with maximum resolution as 1025*1538.

How to know the dpi of images.

Sent from my LM-G710 using Tapatalk

[willus]

"How to know the dpi"... It is not entirely straightforward--I'll see if I can make it more obvious in a future revision, but there should be an associated media box for each graphic that lists the dimensions in points (1/72 inch) and inches.