Well, i have a web page where i am displaying few images. But my problem is that i don\'t want user to download or save those images. I can apply watermark to those images b
Try to use flash to load your image, use flash to decode your encoded images. And this still can not prevent user to take a screen capture.
As mention in all the answers, there is no way to prevent users from saving the image, however you can try to make it hard for a user to do it.
although this is not good performance, you can split the image into many small pieces, making it harder (but not at all impossible) to save them and join them.
There's no absolute solution to prevent user from downloading your image. If you publish image in the web,just assume that somebody can copy it. Whatever your solution, in the end user can take a screen shot anyway.
There are so many ways to download images from website, so whatever you do at the end of the day someone is going to download it.
Prevent users from downloading images it's a waste of time because even if they cannot download the image, they always could do an screenshot :-(