PDF (I am waiting for urgent answer and solution)

[Adam-2000]

It is very difficult to open pdf files from a mobile phone, after reaching a certain page, almost all blank pages appear, not opened

What's the solution?

[ls_rbls]

Hi,

Can you provide more info about the mobile device that you're using, the operating system and if your Adobe Reader mobile app is updated to its latest version?

Also briefly describe which steps have you followed so far to troubleshoot the issue. Was everything working fine before and all of a sudden the app started misbehaving after an update?

[Adam-2000]

Hi before and after the update, I tried the same as the pdf file opening case with other phones but the problem continues the same I want the solutions of the problems.

[Test Screen Name]

We need much more info from you before we can suggest ideas for you to test, or maybe to solve the issues. Demanding solutions instead of answering questions works against you, I am sorry to say. Please start by answering all the questions we already asked, in detail please. There will probably be many more. If you don’t understand any part of the questions, please say. 

[ls_rbls]

Ok, so if I understood correctly this is only happening with one PDF file not every PDF?

Does the same behavior occurs if you try opening the PDF file in a computer device with macOS or MS Windows?

So what you're saying is that it doesn't matter on which mobile device you try (either Android phone or tablet, or iPhone or iPad with whatever version of iOS) the PDF won't open?

If you're using iOS, are you able to at least be able yo view the PDF  using Safari web browser or iBooks, for example? 

[Adam-2000]

This problem only happens on mobile phones and tablets but when I try it on the computer it is easy to open pdf files What's the solution?

[Adam-2000]

This problem only happens on mobile phones and tablets but when I try it on the computer it is easy to open pdf files What's the solution?

This problem happens with certain pdf files.

[ls_rbls]

What app do you use on your phone to open and view PDF documents?

[Adam-2000]

I am using adobe acrobat reader.

[Dov Isaacs · Accepted solution]

I corresponded to user Adam-2000 offline two days ago. He shared some of his problematic files with me and with my usual dilligence, found out what was really going on.

(1)  The files also render slowly with Acrobat Pro DC on my desktop system with Xeon processor, tons of very fast memory, souped-up video card, and SSDs. They render much slower on my iPhone 11 Pro Max and iPad Pro. I can only assume that they look like they are hanging on older, much slower mobile devices.

(2) For the file I examined in detail, I found that behind the text of pages beginning around page 22, there were multiple layers of transparent raster images, JPEG2000-compressed, and with a Pantone spot color channel. Since the text was knock-out and opaque above the background, it did not contribute to the complexity and thus the rendering performance of the document.

(3) I performed a number of steps using Acrobat Pro DC to yield a file that rendered very quickly without any loss for purposes of display. I converted the Pantone spot color to process CMYK (the background raster images were DeviceCMYK already). This would only be an “issue” if Adam-2000 was actually going to print to a device that actually had that spot color (which wasn't out of typical CMYK gamut, by the way), I then flattened the PDF file's transparency and in the process ended up with regular JPEG compression instead of JPEG2000 (JPEG2000 compression has performance issues both encoding and decoding due to the more compute-intensive nature of the compression algorithms). The original background images were 150dpi and I made sure that the final background image was 150dpi.

The resultant PDF file displayed without any performance problems on my mobile devices - not as high performance as simple pages with no background from a Word document with no graphics - but quite acceptable.

I e-mailed the resultant PDF file back to Adam-2000. His response back to me is that “he can't understand.”

There isn't anything more that Adobe or I can do for Adam-2000 since the problem was really that of the original content and not taking rational steps to simplifly same for production.

[Test Screen Name]

Thank you for sharing your analysis Dov, you saved us all a lot of time, since nothing is wrong with the software. Adam-2000, do you understand that demanding a solution when there is no problem will not succeed. Some files are slow for all of us.  

[Adam-2000]

I want a solution to all problems

[Adam-2000]

Hello, can you make the pdf files that I will send to you quickly without degrading the quality?

[Adam-2000]

Hello, can you make the pdf files that I will send to you quickly without degrading the quality?

[Test Screen Name]

Did you report the problem as I recommended? 

[Adam-2000]

Can't understand, can you explain in detail?

[Test Screen Name]

No. I already explained in detail how and where to report. Demanding a solution is useless. You must follow the rules. 

[Dov Isaacs]

Adam-2000,

We have done due dillegence in examining one of your PDF files. As indicated above and in my detailed response to you via direct e-mail, the performance issues you are encountering with your PDF files have to do with the complexity of those files and attempting to view them on platforms that often have much less resource than a desktop computer.

I provided detailed information to you as to the source of the problem in terms of the multiple layers of transparent images with a spot color chanel beneath your text. Flattening those multiple transparent images down to a single full page opaque image and placing same in InDesign, with the spot color output as process, would dramatically increase viewing performance.

I also provided details in that e-mail as to how I used Adobe Acrobat Pro DC's Print Production tools to “fix” the slow-rendering PDF file after the fact.

For better or worse, neither I nor Adobe, nor these online communities are in the business of fixing customer files “after the fact.” In my e-mail to you, I outlined exactly what I did in Acrobat Pro DC to “fix” one such file using a number of the print production tools available therein. It is now your responsibility to fix the other files preferably by fixing the source per above or by doing an after-the-fact fixup in Acrobat Pro DC. If you choose to hire someone to do this work, expect to pay for up to several hours worth of time to complete the work.