I was wondering since emulators can improve the quality of the games adding AA, IR, AF, 3D and etc... With all this talk (and hype of HDR) does anyone know if this improvement can be added on dolphin and maybe others emu as well?
Depending on the rendering system, HDR can be super-duper easy to add, or impossible. If the whole pipeline uses floating point (or integer with a large range) colours throughout, then it's simply a matter of scaling to (for example) 0-1023 instead of the usual 0-255 after gamma correction. However, it's completely possible that software does some post processing after conversion to 8-bits-per-channel, and that kills any chance of HDR output altogether.
In the case of Dolphin specifically, it's possible that a game could work either of these ways, and I'd imagine there's little that can be done to detect or work around that - even if Dolphin's using standard API functions to convert int or float vectors to colours right before displaying them, there's no guarantee that the game hasn't already removed all the dynamic range at some point earlier in the process.