Protect Online Images
Most images displayed in a browser are in either JPEG (Joint Photographic Experts Group) or GIF (Graphics Interchange Format) formats. There is a third graphics standard supported by the Web (though not supported by all browsers) is PNG (Portable Network Graphics). All images viewed online through a browser has only a resolution of 72 dpi (Dots Per Inch).
People will suggest all sorts of ideas to protect images. The bottom line is these ideas just make it more difficult for your innocent users to view your images, while at the same time making those that would steal them just a little more curious about all the loopholes; to the point of actually taking them just to see if they can.
There is a variety of methods used to make it more difficult for people to download images from web sites. In normal HTML, images can be saved using the web browser, either by simply saving the web page as a whole or single images by right-clicking on the image and choosing "Save Picture As" or "Copy" from the menu that appears.
Disable the right mouse button using JavaScript
This will disturb many users who may legitimately wish to do other things from the menus you have disabled. It is also possible to tell some browser software to ignore such code, so one with a serious interest in downloading your files will not be so easily deterred.
Splice the images into small sections and to load as a seamless mosaic
This feature is built into a number of web graphics applications such as Adobe PhotoShop/ImageReady. Actually, this technique has little real impact on protecting the image. The same HTML code that displays the parts of the image can also be used to automatically reconstruct it, or you can use screen capture to save as a simple file or simply paste the pieces together in any graphics editor.
Placing a "transparent" image on top of the image
This technique places a transparent image on top of the image you are trying to protect. If uses the right mouse button to capture the image, they will capture the transparent image. Then they will view the source code and find the image wanted and download it directly. This method will only slow down those wanting your image.
Web page encrypting
There are several services and applications (such as ProtWare's HTML Guardian or Weblock Pro) available that appear to encrypt the web page source code, including the JavaScript "Disable Right Mouse Button."
The Right Mouse Button to capture the image will still work. Even if you include the JavaScript to disable right mouse button will not protect your image. In actuality, the source code is converted into JavaScript. Web browsers have built-in JavaScript generators. Viewing the source code will look encrypted and impossible to find the image. Well that is not true. Anyone familiar with JavaScript can apply one line of code and the "so-called" encryption is decrypted.
Recommendations for securing your images
Images for the web are not suitable for printing due to a much lower dpi.
You can place a visible watermark on your image that would be difficult for most users to remove.
Allow the user to view thumbnails, but require registration for the full-blown size. Make higher resolution images available for viewing or download using a secure section while only displaying images at relatively small sizes on the web page. This allows you to safeguard the commercially valuable versions of your work without difficulty. This can be combined with an online payment system or a password protected section.
One of the most effective methods of preventing downloads is making use of proprietary systems such as Macromedia Flash to display your pictures. Flash can prevent downloads using its built-in security features.
Another effective technique is using the PDF (Portable Document Format) format for displaying your images. Security features with Adobe Acrobat can prevent the download or use of the image. With PDF, you can build security into your pages that restricts what people can do with your page (even if they have Acrobat) unless they know one of two passwords.
One password is used to stop the page from being able to be opened at all by anyone who does not know it.
The other password can be used to stop people who are viewing the page from performing one or more of the following: printing the page, changing the page, selecting text and graphics, and adding or changing note or form fields.
Then again, anything that is displayed on a screen can actually be copied using suitable screen capture software or screen capture. It is not possible to completely prevent the downloading of images from the web. You easily can make it considerably harder for the casual saver of images, or those who are computer illiterate, but these represent no financial threat. Such measures are likely to make your site less accessible and slower to use, and may prevent "fair use" of your material, for example by students. Those who are determined and knowledgeable will always find a way around your protection schemes.
Copyright
Information here about copyright is given in good faith and should not be taken as legal advice.
Reference: http://www.copyright.gov/
Details of copyright law differ from country to country, although the general principles in most countries are governed by the Berne Convention on copyright and are thus similar.
All photographs taken are automatically copyrighted, and unless you are employed with a contract including photography among your duties, you own the copyright. If you are employed as a photographer, your employer will own the copyright. Freelances own the copyright on work whether it is commissioned or not. Copyrights can only be assigned to someone else in writing. If you have been photographing for a very long time, different laws may apply to your earlier work.
In some countries, it is still necessary to include a copyright endorsement, marking the work with the copyright symbol (c), the maker's name, and the date of creation. Since the Internet is international, it is reasonable to include this information on any page containing your pictures. Some photographers include this information actually within the image area, so that if the image is copied this will also be copied. However, such information can easily be retouched out by the unscrupulous.
In the USA, there are legal advantages in registering your copyright and this can be done for batches of images at a time. Registration of your images enables your to claim damages in US courts of copyright infringements that exceed the actual financial loss.
Unless you own a copy of the actual work you would need to reproduce from a reproduction that was itself out of copyright, although as a strictly mechanical work, the reproduction may not qualify for copyright in itself. Check with a lawyer before going ahead into this legal entanglement.
Copyright in any case does not prevent all acts of copying. Copies may legally be made for individual research or private study or for reproduction for the purposes of criticism and review, so long as the photographer is properly credited. However, few publishers will normally insist that permission is gained for reproductions to accompany reviews or critical articles. You can also make slides or prints for your own teaching purposes (but not photocopies etc); for examination purposes you can even duplicate images. There are also some other allowed uses of copyright material, and those interested should a lawyer dealing with the details of the law in their country.
Watermarking and fingerprinting your images
This method allows you to add a digital watermark or signature to each of your images. The watermark is invisible to the naked eye, but can quickly be retrieved using a watermark reader. Additionally, some services (like Digimarc) will search the web for your images and generate a report for you so that you can confront the offender. Watermarking does not prevent someone from copying an image; it simply makes tracking down the offenders possible.
