[Unsolved] Change the quality of textures of specific type independently?

Hi all, I've been thinking about this for a while now, but would it be possible to change the quality of all textures of the same type in the project? For example, lower/increase the resolution or anisotropic filtering on all normal maps? I've seen some (non-Unity) games have separate settings for Spec., Normal, Displacement and Albedo (color) map quality. Could this be achieved with Unity?

 

The quality of textures yo can manage over the quality settings.
Texture filtering can be found there too.
You can switch between different quality level at run-time via code.
http://docs.unity3d.com/ScriptReference/QualitySettings.html

You can set a shader max lod that can force shader into a lower version for faster rendering.
http://docs.unity3d.com/Manual/SL-ShaderLOD.html

For the resolution, you can set it by code.
http://docs.unity3d.com/ScriptReference/Screen.SetResolution.html

 

Thanks a lot.
I already knew about Screen.SetResolution, but I don't actually change the resolution of the game window, but the textures (I know that the Quality Settings give an option to lower the resolution of textures, but it reduces the quality of all textures). ShaderLOD is something I'll look into, I think it might be the key to solving this one.