1. Put this page under https domain
2. This page html head tag contains following code
<meta http-equiv="Content-Security-Policy" content="upgrade-insecure-requests" />
3. Add a http hosted image with code here
<img width="50%" src="http://static.junhuih.com/https-test/NowYouSeeMe.jpg" />
You can see below image like regular, but, when you open browser developer tools, and throught network tab, you will see the image request is changed to https
