How to open a file in ruby?

I am trying to display an image in a ruby program. I have thought of a way to do this but it may be a completely crazy idea that wont work. what i am thinking is having a html file in the same folder as the ruby code. so on the last line of code it accesses that file and basically redirects the person to the web page with the image that i want them to see. if anyone knows how to do this or knows another method of displaying the image that would be great. i am working on a mac