How to disable save image and change the suffix to .htm when saving it?

How can I disable save image and change the suffix to .htm when saving it?

In fact, I need to change suffix during save, as i开发者_JAVA百科s done on this site: www.alexbuga.com

The website you linked to uses images as a background, so instead of

<img src="/path/to/image.png" width="200" height="200" alt="An image">

you would do this

<div style="width:200px; height:200px; background: #fff url('/path/to/image.png') 0 0;"></div>

or similar. This doesn't exactly disable saving images but it's how the website you linked to works.