How to Create "Picture Compare" Button

I want to create a "Picture Compare" Button Like This One, How to do it?


how to arranged standalone viewer like This?

Now this is my standalone image viewer

The comparison tool used in that video is Beyond Compare.

Have a look at

You may be able to adapt it to your needs

Thanks for replay, I already use that. But the zoom is not so smooth in stand alone viewer.

Don't really understand why that should be so as they are simply two separate instances of the Opus viewer.

I get the same zoom behaviour in the macro as the single image viewer instance on my system.

two separate instances of the Opus viewer is need for compare two picture not for the zooming. I Say the zoom is not so smooth in all over the stand alone viewer like Adobe photoshop CC