I was tired to have the same icon for Houdini and the Mplay Image Viewer so I created a new one. It's free but please give me a donation of 1 000 000 trillion euros.

How to install:
Put the ico file Houdini Image Viewer Mplay Icon.ico in C:\Program Files\Side Effects Software
Open start menu, right click on image viewer icon then “pin to start”
Open start menu, right click on image viewer pinned icon then more > open file location
In explorer, right click on image viewer icon then properties
Button “change icon” then button “browse”
Find the icon in C:\Program Files\Side Effects Software , apply close etc and voila!!