Folow mouse movement to pan image when zoomed in
It is somewhat cumbersome to pan images with mouse when zoomed in. Currently the only way to pan with a mouse is to click and drag. This is not very user friendly, particularly when a lot of scrolling up/down or left/right is required (such as when viewing a very wide panorama). Using the keyboard arrow buttons moves to next image. It would be nice if keyboard movement could be used to pan the image, but even better would be to pan by following mouse movements. Note how flickr has implemented this when zoomed in to a large image: https://www.flickr.com/photos/patricksloan/14587064250/
