preventing images saving

[Fred]

hi, is there some way to prevent(at least for not so advanced users)
image saving on local disk; currently i use javascript which handles the
right mouse button click, but all it takes is to disable js in the browser ?

TIA

 

[Gabriel Magaña]

In a nutshell, no.

You can have little tricks, ActiveX objects, etc... but the fact is that if
the client is already viewing your image, it's already on his hard drive, at
least in the short-term cache.

 

[darrel]

hi, is there some way to prevent(at least for not so advanced users) image

saving on local disk;

Yes. don't upload the image in the first place.

Otherwise, if you want people to see it, then they've already downloaded it.
That's how the internet works.

-Darrel

 

[Brian Cryer]

hi, is there some way to prevent(at least for not so advanced users) image
saving on local disk; currently i use javascript which handles the right
mouse button click, but all it takes is to disable js in the browser ?

TIA

The others are right, you can't. But I think you already know that which is
why you said "for not so advanced users". Beyond JavaScript other ideas I've
come across which might help:

* Watermark your images, so its clear where they came from.

* Put a transparent gif over the top of all your images, so a right click
downloads the gif and not the image they are seeing.

Hope this helps.

 

[Kevin Spencer]

* Watermark your images, so its clear where they came from.

Good advice. If images could not be copied, there would be no copyright
laws. At least this gives you some legal redress, if you can track them
down.

* Put a transparent gif over the top of all your images, so a right click
downloads the gif and not the image they are seeing.

And what happens when they figure out they've downloaded a transparent gif?
Well, I can give you a few scenarios. They all start with going back to the
page. First, they look at the HTML source code, get the URL out of that, and
download the image. Or, they use CTRL/PRINT_SCREEN to copy the image. Or,
they go into their Browser cache to get the image that was already
downloaded. Or, they use the File|Save as Web Page... command in IE. Or,
they use their favorite HTML editor and open the page for editing, or just
download the whole web site. Or ...

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Who is Mighty Abbott?
A twin turret scalawag.

 

[Gabriel Magaña]

Good advice. If images could not be copied, there would be no copyright

laws. At least this gives you some legal redress, if you can track them
down.

Don't forget if you want to have any legal redress (in the USA) aside from
being able to order them to take your content off their site, you have to
register the trademark with the US Patent and Trademark office. Can't sue
for money unless it's registered.

* Put a transparent gif over the top of all your images, so a right click
downloads the gif and not the image they are seeing.

And what happens when they figure out they've downloaded a transparent
gif? Well, I can give you a few scenarios. [...]

Agreed, but in all fairness, he was talking about the avg user, not someone
technically savvy... When you get to the "View Source" stage, you've lost
at least 90% of the users out there...

 

[Gabriel Magaña]

register the trademark with the US Patent and Trademark office. Can't sue

OOps! Make that U.S. Copyright Office...

 

[Fred]

tnx for all answers, what i was looking for was some smart usage of
Response.Write to directly stream bits instead of providing hardcoded
link; i`ve heard victoriassecret.com uses some similar method

 

[Brian Cryer]

tnx for all answers, what i was looking for was some smart usage of
Response.Write to directly stream bits instead of providing hardcoded
link; i`ve heard victoriassecret.com uses some similar method

If I understand what you're hinting at then I don't think it helps. I have
an application that uses a third party component to generate a map of London
on a website. The image is generated as a stream, but I can still right
click it and download it or save the entire page. So I don't think that
generating it via a stream would help you.

 

[Kevin Spencer]

Don't forget if you want to have any legal redress (in the USA) aside from

being able to order them to take your content off their site, you have to
register the trademark with the US Patent and Trademark office. Can't sue
for money unless it's registered.

Copyright and Trademark are 2 entirely different things, and fall under 2
entirely different bodies of law. In fact, copyright is is governed by
international law in many countries, and is automatic in most. See
http://en.wikipedia.org/wiki/Copyright.

Agreed, but in all fairness, he was talking about the avg user, not
someone technically savvy... When you get to the "View Source" stage,
you've lost at least 90% of the users out there...

Computers are excellent a a few things. One of them is copying digital data.
Another is sending digital data to other computers. What does this say about
the protection against (by your estimate) "90% of users out there"? Well,
let's talk about viruses, worms, and trojan horses. These are digital data
that nobody even wants. How are they spread? One computer copies the data
and sends it to several others. Each of these sends it to several others.
And so on.

Once something is copied, it can be distributed. So, protection from "90% of
users" isn't protection at all. In fact, if something is attractive enough
to warrant copying and re-using, it is highly likely to be both copied *and*
distributed.

You will also note that among the (few) methods I enumerated (there are many
others), only *one* of them involved viewing the source code. What
percentage of users doesn't know how to use the "File|Save As..." menu item
present in most applications, including browsers?

Again, if images and any other published material could not be copied, there
would be no need of copyright laws. Copyright laws exist to provide redress
for people *when* their material is copied. It is not preventative.

Why people seem to understand and accept that an image in a book can be
easily copied using a copier machine, but for some reason an image on a
computer, which *is* a copying machine cannot, is beyond me.

But I do know that advising someone to do something that is useless is to
give useless advice. For example, to advise someone that they will not get
HIV if they don't have sex with prostitutes has a damaging effect, because
it encourages them to have sex with anyone that is *not* a prostitute. It
also doesn't inform them of the various other ways which they might contract
HIV.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Who is Mighty Abbott?
A twin turret scalawag.

Good advice. If images could not be copied, there would be no copyright
laws. At least this gives you some legal redress, if you can track them
down.

Don't forget if you want to have any legal redress (in the USA) aside from
being able to order them to take your content off their site, you have to
register the trademark with the US Patent and Trademark office. Can't sue
for money unless it's registered.

* Put a transparent gif over the top of all your images, so a right
click downloads the gif and not the image they are seeing.

And what happens when they figure out they've downloaded a transparent
gif? Well, I can give you a few scenarios. [...]

Agreed, but in all fairness, he was talking about the avg user, not
someone technically savvy... When you get to the "View Source" stage,
you've lost at least 90% of the users out there...

 

[Brian Cryer]

Copyright and Trademark are 2 entirely different things, and fall under 2
entirely different bodies of law. In fact, copyright is is governed by
international law in many countries, and is automatic in most. See
http://en.wikipedia.org/wiki/Copyright.


Computers are excellent a a few things. One of them is copying digital
data. Another is sending digital data to other computers. What does this
say about the protection against (by your estimate) "90% of users out
there"? Well, let's talk about viruses, worms, and trojan horses. These
are digital data that nobody even wants. How are they spread? One computer
copies the data and sends it to several others. Each of these sends it to
several others. And so on.

Once something is copied, it can be distributed. So, protection from "90%
of users" isn't protection at all. In fact, if something is attractive
enough to warrant copying and re-using, it is highly likely to be both
copied *and* distributed.

You will also note that among the (few) methods I enumerated (there are
many others), only *one* of them involved viewing the source code. What
percentage of users doesn't know how to use the "File|Save As..." menu
item present in most applications, including browsers?

Again, if images and any other published material could not be copied,
there would be no need of copyright laws. Copyright laws exist to provide
redress for people *when* their material is copied. It is not
preventative.

Why people seem to understand and accept that an image in a book can be
easily copied using a copier machine, but for some reason an image on a
computer, which *is* a copying machine cannot, is beyond me.

But I do know that advising someone to do something that is useless is to
give useless advice. For example, to advise someone that they will not get
HIV if they don't have sex with prostitutes has a damaging effect, because
it encourages them to have sex with anyone that is *not* a prostitute. It
also doesn't inform them of the various other ways which they might
contract HIV.

Kevin,

I think you should re-read the original post. Quote "is there some way to
prevent (at least for not so advanced users) ..."

He's been advised that 1. he cannot stop people copying images and 2. that
there are ways to make it more difficult (which there are - at least for
"not so advanced users"). Which bit of advice are you saying is useless?

 

[Kevin Spencer]

I think you should re-read the original post. Quote "is there some way to

prevent (at least for not so advanced users) ..."

He's been advised that 1. he cannot stop people copying images and 2. that
there are ways to make it more difficult (which there are - at least for
"not so advanced users"). Which bit of advice are you saying is useless?

I was looking past the partial solution he proposed, to the problem that it
was supposed to address. The problem could be stated as such: "How do I
prevent theft of images from my web application?" His partial solution was
to somehow prevent the copying of images by a limited number of people. This
solution, however, is in itself, seriously flawed. I believe I addressed the
reasons for coming to this conclusion. Therefore, any advice which
encourages this useless solution is useless.

People come here looking for help because they do not know something. They
are looking for someone to help them by telling them what they do not know.
I looked past the fact that this person was asking for something to the
reason that he was asking for it. That reason is what I am addressing. If he
had cancer, and he thought that smoking a pack of cigarettes would cure it,
would you just give him a pack of cigarettes, or would you tell him that the
cigarettes would not only not cure his cancer, but likely kill him quicker?


Therefore, the best advice that someone can give to anyone who has the
misguided notion that they can obtain any sort of protection against such
theft is:

(1) Tell them the truth, and discourage them from deceiving themselves. Any
offer of a non-solution simply reinforces the deception.
(2) Offer solutions that are realistic, such as watermarking, which does not
prevent theft, but make the tracking-down process easier.
(4) Be realistic about the value of those things which they cannot protect.
If those things are indeed valuable, and one will incur real loss, do not
make them publicly available. Otherwise, accept the inevitable.
(3) Encourage them to consider the expenditure of resources necessary to
implement a non-solution, and to concentrate instead on those things which
are possible and desirable.

Anyone asking such a question is not well-educated regarding these things.
There are literally dozens of millions of computers connected to the
Internet, including search bots like Google Images, which download content
from web sites continually. Many people new to the WWW are not aware of
this. Within a few days of publishing, one's content is already spread far
and wide. If images are desirable, they *will* be copied, and they *will* be
used. If they are not desirable, they *will* be copied, and they *may* even
be used.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Who is Mighty Abbott?
A twin turret scalawag.

 

[Gabriel Magaña]

Copyright and Trademark are 2 entirely different things, and fall under 2

entirely different bodies of law. In fact, copyright is is governed by
international law in many countries, and is automatic in most. See
http://en.wikipedia.org/wiki/Copyright.

Sorry, I don't believe in wikipedia... A far more reliable source of info
would be http://www.copyright.gov/help/faq/ But I did correct that I cited
the wrong office for copyrights. My statement that you cannot sue for
copyright infringement unless the copyright is registered still stands.
It's a minor detail, but I included it for completeness' sake. (See
http://www.copyright.gov/help/faq/faq-general.html#register)

Computers are excellent a a few things. One of them is copying digital
data. [...]

Now you are preaching (prostitutes and HIV?)... Its cool to talk about all
sorts of stuff, but let's not redefine to problem to fit the solution.

 

[Kevin Spencer]

Copyright and Trademark are 2 entirely different things, and fall under 2

Sorry, I don't believe in wikipedia...

Ah, we have a religious nut on our hands. I don't believe everything I read
in Wikipedia, but I did quite a bit of research before answering (I don't
like to provide bad information).

A far more reliable source of info would be
http://www.copyright.gov/help/faq/

Hmmm, seems you were the one to bring up international law in the first
place. But let me quote the U.S. Copyright office, from *your* link:

"When is my work protected?
Your work is under copyright protection the moment it is created and fixed
in a tangible form that it is perceptible either directly or with the aid of
a machine or device. "

"Do I have to register with your office to be protected?
No. In general, registration is voluntary. Copyright exists from the moment
the work is created."

"In general, copyright registration is a legal formality intended to make a
public record of the basic facts of a particular copyright. However,
registration is not a condition of copyright protection."

Furthermore, the U.S. ias a signator of the Berne International treaty:

http://www.wipo.int/treaties/en/ip/berne/index.html

Now you are preaching (prostitutes and HIV?)... Its cool to talk about
all sorts of stuff, but let's not redefine to problem to fit the solution.

It's called "an analogy." If you didn't get it, well, I can't help you. You
will believe what you want to believe, regardless of fact. But I'm sure that
everyone else is quite well-informed by now, so I've accomplished my task.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Who is Mighty Abbott?
A twin turret scalawag.

Copyright and Trademark are 2 entirely different things, and fall under 2
entirely different bodies of law. In fact, copyright is is governed by
international law in many countries, and is automatic in most. See
http://en.wikipedia.org/wiki/Copyright.

Sorry, I don't believe in wikipedia... A far more reliable source of info
would be http://www.copyright.gov/help/faq/ But I did correct that I
cited the wrong office for copyrights. My statement that you cannot sue
for copyright infringement unless the copyright is registered still
stands. It's a minor detail, but I included it for completeness' sake.
(See http://www.copyright.gov/help/faq/faq-general.html#register)

Computers are excellent a a few things. One of them is copying digital
data. [...]

Now you are preaching (prostitutes and HIV?)... Its cool to talk about
all sorts of stuff, but let's not redefine to problem to fit the solution.

 

[Gabriel Magaña]

Sorry, I don't believe in wikipedia...

Ah, we have a religious nut on our hands.

No you don't, you have someone that would rather get the information from
the main source than second-hand.

Hmmm, seems you were the one to bring up international law in the first
place. But let me quote the U.S. Copyright office, from *your* link:

??? Hehehe! I have NO freakin' idea of what you are talking about, maybe
you are mistaking me for someone else. My answer to your post was
basically: In the US you cannot sue for copyright infringement unless you
register the copyrighted work first, and I also made clarification we were
talking about savvy users. There's nothing international about my reply.

 

[Brian Cryer]

I was looking past the partial solution he proposed, to the problem that
it was supposed to address. The problem could be stated as such: "How do I
prevent theft of images from my web application?" His partial solution was
to somehow prevent the copying of images by a limited number of people.
This solution, however, is in itself, seriously flawed. I believe I
addressed the reasons for coming to this conclusion. Therefore, any advice
which encourages this useless solution is useless.

Totally agree. But this was the first thing he was told.

 

[Brian Cryer]

The others are right, you can't. But I think you already know that which
is why you said "for not so advanced users". Beyond JavaScript other ideas
I've come across which might help:

* Watermark your images, so its clear where they came from.

* Put a transparent gif over the top of all your images, so a right click
downloads the gif and not the image they are seeing.

Another idea:

* Segment the image into a number of smaller images which each need to be
loaded to see the full thing.

This just makes it more work for someone to get the image. Like all the
other ideas (other than watermarking) a simple screen dump will still
capture the image, but it will hinder most other methods.