If you want to view the images, and want to know the mouse location and pixel values, you may install some image viewer(s). I am at the same boat. After some research, I found that there is no light-weighted image viewer which can show the pixel values at Linux platform up to my best knowledge. So I decide to write one by myself. It turns out web browser + Javascript are good enough to do this. Here is the Javascript based image viewer:

iview.html

You can save the source code locally and click the local html file to run it locally.