Rasterize a file within Adobe Acrobat Pro

[Diane32394960k6md]

I am interested in being able to rasterize a pdf and also lowering the resolution within Acrobat, while keeping the file a pdf. Is this possible? I have tried Reduced Size PDF, as well as Compress a PDF, but with no luck. I believe I can accomplish what I am aiming for when exporting the inital pdf from InDesign, but I am hoping to be able to do it within Acrobat. 

[gary_sc · Accepted solution]

Yeah, sadly, there's no good way to protect a PDF from folks who want to access the document. Like a house key, password protection only keeps out the "mostly honest" folks. 

Remember, if you did rasterize the PDF, and make it a PDF of an image, all the person has to do is to either print that, and then scan it, then OCR it. Alternatively, many of the screenshot applications out there can OCR directly within a screenshot. 

And yes, you nailed it; this is "just part of creating a digital product." Perhaps if you only sell it to honest people? :>)

Actually, I just thought of something. I wonder if it's possible for a "key" to be emailed to the person opening the file — if it's been registered for that person. Without the key, the file cannot be opened. Using the Key, the file would open to the first page with an option to enter your email and send that off. When received by the company who created the key, a return number would be sent that has a one-time use for opening the file. As you point out, this would not stop GoodNotes from generating a new copy, but if I paid $$, I'd be a lot less likely to generate a clean copy.

I am unaware of anthing like this out there, or even if it's possible. Maybe someone who comes across this can make it happen. In the meantime, just cross your fingers like everyone else; put a password on it and cross your fingers. Sorry

[gary_sc]

Hi, @Diane32394960k6md, what is your goal here? Why do you want to rasterize the PDF?

Probably the easist way to do this is to save it a JPG image. Then open the JPG in Acrobat and save it as a PDF.

However, if your goal is to make the PDF smaller in storage size, this is not the way to do it. Assuming that the original PDF has a lot of text in it, text is a very compace storage media that is vector based. Once you convert that into individual pixels, each pixel has to be accounted for. If the document is color, than you multiply the storage size by three times (each channel of red, blue, and green have to be accounted for, even with black text).

So, again, what is your goal here? What are you expecting to happen?

[Diane32394960k6md]

Thanks for your response @gary_sc ! My overall goal is to protect some pdfs as much as possible from being edited or distributed without auhorization. I am creating the first of several large documents (mostly forms/calendars) that will be available for purchase to use on the GoodNotes app.

When creating the initial pdf, I can protect it with a password. In GoodNotes, a protected pdf can be imported without the password, which is good for this situation... except that it is also possible to export a pdf from GoodNotes, and in doing so does not retain the security feature on the pdf. Basically, if you have a password protected pdf, you can import it into GoodNotes without the password, export it as a pdf and have full access to edit it in Illustrator, Acrobat, etc. My thought was to, at minimum, rasterize the pages to keep the pdf from being edited/updated without authorization.

To your point, I imagine this would cause the file storage size to be larger, and I wondered if lowering the resolution could adequately compensate. The file would only be used on screens, and a high resolution would not be necessary. If it was only a few pages, opening each page and saving as a jpg would be fine, but multiple 400+ page documents would take quite a bit of time. Maybe this risk is just part of creating digital products. Thanks again for responding and I'd be grateful for additional insight you have!

[gary_sc · Accepted solution]

Yeah, sadly, there's no good way to protect a PDF from folks who want to access the document. Like a house key, password protection only keeps out the "mostly honest" folks. 

Remember, if you did rasterize the PDF, and make it a PDF of an image, all the person has to do is to either print that, and then scan it, then OCR it. Alternatively, many of the screenshot applications out there can OCR directly within a screenshot. 

And yes, you nailed it; this is "just part of creating a digital product." Perhaps if you only sell it to honest people? :>)

Actually, I just thought of something. I wonder if it's possible for a "key" to be emailed to the person opening the file — if it's been registered for that person. Without the key, the file cannot be opened. Using the Key, the file would open to the first page with an option to enter your email and send that off. When received by the company who created the key, a return number would be sent that has a one-time use for opening the file. As you point out, this would not stop GoodNotes from generating a new copy, but if I paid $$, I'd be a lot less likely to generate a clean copy.

I am unaware of anthing like this out there, or even if it's possible. Maybe someone who comes across this can make it happen. In the meantime, just cross your fingers like everyone else; put a password on it and cross your fingers. Sorry

[Diane32394960k6md]

I'll look into the option of having a key, I appreciate you mentioning that. Just want to make sure I do my due dilligence, but in the end I think you are right- just put the password on it and cross my fingers! Thanks again for your time.

[try67 · Accepted solution]

This "key" just seems like an unnecessary additional step. How is that any different from paying and getting the link to the file directly?

If you really want to limit who can open a file you need to use DRM technology, which is very expensive and not worth it for most people. This type of technology allows a file to be opened only on specific devices, and prevents most forms of copying and re-creating it.

[gary_sc]

Yes, it is an unnecessary step, but if it's required EVERY time the document is opened, it helps limit pirate copies. 

Think of it this way, as it's not that dissimilar to the extra digits you have to use for 2-factor authentication: I get a document from "Big Corporation" and have a password for that document. However, after I initiated the opening process, they also sent a security code to the phone number on file to complete the process. If I were to give you that document, even with the password, the security code would come to me, not you, and you would not be able to open the file.

I agree with you that this is burdensome, but so is 2-factor authentication. This might work for files that are either very private or the creator does not want to lose control of their document.

But, then again, this is a pie-in-the-sky thought that came to me while trying to help Diane. I doubt if it will ever happen.

[try67]

Why would they need to do it each time? What will stop them from re-opening the original file, once they downloaded it?

[gary_sc]

For the same reason, 2-step verification is required to get into some websites — EVERY TIME.

Look, this doesn't exist. If it ever came to pass, it would likely only be used for documents that warranted this level of security. As Diane stated earlier, it's easy to bypass a document's security by resaving it. Then what? I'm saying, in my made-up universe, that the user could open and read the document, but not print, not resave, not copy, just read. If you wanted to open this up, you'd have to have a username, a password, and the security code emailed to your phone. That's it.

[try67]

I'm not asking why, but how... A website can control the access to it each time you open it. It can consult a database with the user credentials, call external services for verification, check the IP address, cookies, etc. A PDF can do none of those things.

[gary_sc]

I do not KNOW; I can guess if it's linked to a web server of some kind. 

Again, as I stated from the onset, I made this up. Maybe you can figure this out and make $$$$, but I do not know.

[try67]

OK, I see, and I wish that I could! 🙂