Blocking images can't or might be implemented on every website in a single click. I can only tell you how to block loading of images for a specific website on Firefox browser. Please follow the steps given below:
1. Enter a website address and load it. For instance you entered www.techulator.com.
2. You will be seeing a greyish icon (of the shape of a globe) on very right of the web address box. Click on it!
3. A box will popup as you click on it. Hit "More Information" option.
4. A page info window will appear on the screen. There you will be seeing many tabs like general, media, permissions and so. Click on "Permissions" tab.
5. The first content under that tab is about permission for loading images, "Load Images". Uncheck the box under "load Images" option and then check the radio box saying "Block".
You are done. Image loading have now been turned off for techulator.com.