Hi,
I want to prevent the distribution of images from an iphone app that I've authored. As such, I would like to either prevent the screenshot feature from working whilst my app is running or, if the user does take a screenshot, to watermark the image automatically.
Any ideas as to how I could so this?
Even if you could do that, people can always do things like photograph the iPhone with an external camera, which you have no way to guard against. What is your purpose of preventing screenshots?
I'm not sure how the screenshot works. If it simply takes a shot of the graphics buffer then there is no way in app code to prevent it.
However, if it queries the front app for MainWindows its CGImageRef then you might be able to use a UIView subclass to override the default behavior such that instead of returning the image on screen as its CGImage it would return a watermarked image.
Even if this is possible, this would require a great deal of work. You would have to rewrite all the view code to call the unwatermarked image for display internally.
Even if you succeeded, I very much doubt Apple would allow such an app through the app store. Apple doesn't like apps that override default system behavior. They would be concerned that users would think that the failure to take a clear screenshot was a fault of the iPhone and not the app.
Good luck providing intellectual property protection for images. No one has succeeded so far.
Heck, you can't even protect printed works anymore. The fidelity of the cameras that every device now seems to carry is just to high. Recently, I was worried about losing some old family photos and I didn't have a scanner so I photographed them with my iPhone camera. I was shocked to see that the resulting photos were as good as that produced by a low-end scanner. Given that these photos would be used in a digital medium anyway, I now have no real need to scan them.
You're probably better off offering an inexpensive in app purchase mechanism than investing time trying to prevent copying. If people want the images bad enough, they can get them.
I don't think this is a sufficient answer. While I understand that apple wants to offer this functionality. It really smacks of providing a mechanism for users to break the law and/or prevents a publisher from protecting their rights if they choose to use the medium. The argument that you can take a photo is fallacious. You can, but its not nearly the same as taking a pixel for pixel exact screen-shot of the content offered.
I suppose that you could create a situation where all of your content was not displayed at the same time so they would have to piece together the whole from screenshots. Or mabye always have your copyright watermark on the screen, but that seems like a poor substitute for just allowing the app developer to turn off screen shots. It could pop up a message instead telling the user that they don't get to have a screenshot of that portion of the program due to copyright.
Most people seem to fall back on the argument that you don't have use Apple's products if you don't like their rules, and they have the right to make the product any way they want.
I would tend to agree up to a point. Apple is certainly free to make or not make products. But I would content that where they deliberately configure there products in such a way that common practice must change to fit their visions of content delivery, we should certainly take issue. Its not a question of IF they can protect the rights of the people making content, its a questions of will they. In one sense, their closed system offers application developers a great platform, because piracy is very inconvenient with a single software source. But on the other hand they don't value visual content highly enough to provide protection it in the sdk.
Of course, it may not make sense to restrict your content, as sharing will likely result in more sales and there is probably more to your application that the content, but I would agree with the first person. It should be an option, and not making it an option is certainly a deliberate attempt to limit the choice of content creators in an arbitrary fashion.
Not really a surprise, as their whole method of operating is to make all of the decisions on how their devices can be used by the consumer.
What everyone should ask themselves. If I bought a pc or a desktop mac and someone told me I couldn't buy programs from anyone, I only had one choice for the source, would I be happy?
Or if I bought a blueray player and was told that I could only use movies from one company would I be happy.
There is a reason why we like our technology open, and it directly relates to our freedom to consume from providers in an OPEN market. When you close a given channel that includes millions of people and insist that the best experience is only available to consumers that buy approved product that follows a set of arbitrary restrictions. You subvert the freedom of the individual to exercise the inverse of the freedom of speech. The freedom to consume the speech that we choose. Is not preventing someone from consuming the message of another just as frustrating as not allowing that person to speak.
Again, you could say that a person can choose another technology, but in this case isn't that like telling a person that they can ride a bike instead of owning a car? Apple has the best technology, does that mean that they then get to set all the rules regarding what we expect from our technology?
Another example would be if you were only free to speak where no one was. Is that really freedom of speech? Move along son.. you can't talk that way here.... Isn't their policy the digital equivalent?
I don't know the answer, but if we can tell McDonald's how to make their fries, we can certainly tell Apple that they aren't allowed to sell arbitrarily closed technology. Would they take their toys and go home. Who knows. I tend to think that if you legislated that they could not approve or disapproved of applications based on content they would be relieved that they were off the hook. If someone didn't like an app, they could just say, hey its the law, we have to allow this. Or, they could sandbox an open section of thier device and allow alternate software vendors in a DMZ.
What was the discussion.. copyrighted images? :).. Oh yeah. I want to turn off screenshots too.. Anybody?