Optimizing images using imagemin Grunt plugin

I have tried to use Prepros and one feature that I like is its image optimization. This feature reduces the byte size of of the image and this means faster web page loading. But Grunt is the workflow management I am using. Good thing is Grunt has this Imagemin plugin which can also optimize images (jpeg, png and gif). Lets take a look on how to setup and use this plugin to our workflow.