How to generate a styled image with out actually creating it?

Question

There is a content type in my website called image and it has an image field. There are about 16GB images in my website and people have uploaded very high quality images.

There is an image style in my website which uses the original image plus a watermark. This causes double space consuming. People are only allowed to download this version. The number of images in my website is growing very fast and it needs lots of space.

I need to show the styled version to the user with out creating it in \styled directory.

Is there any way to handle this problem? Is there anyway to keep the site working like now, but instead of creating a separate copy of the original image, display the styled image and generate download link to the user in any other way?

Thanks.

Answer 1

The only way would be to use CSS and put a div with a background transparent image of the watermark overlay on top of the actual image using the z-index: attribute.

You would risk that people could inspect element or view page source and find the direct link to the image, or use a tool to strip all css and then save the image.

For total security, I'm pretty sure there is no other way than having the watermark on the image itself.