IMO, what none of these techniques address is being able to on-the-fly detect if Retina and show higher-res images in a slideshow format. There is plenty of ta

IMO, what none of these techniques address is being able to on-the-fly detect if Retina and show higher-res images in a slideshow format. There is plenty of talk out there about how to display bg images but not much (none?) that I have found to address the use case I talked about above.