With Mapillary in mind, I have made a demo of a tool that can be used to enhance pictures in the browser. Myplan is to integrate it into a bigger tool that lets people save the enhancements and fetch rendered versions of those images. There is a lot of work untill that, but you can take a look at a very rough GUI: http://zip.dk/mapillary/dev/demo/
What do you think?
The code is free software and there is a link to the GitHub repository.