you can use
DisplayInformation di = DisplayInformation.GetForCurrentView();
ResolutionScale rs = di.ResolutionScale;
ResolutionScale will give you scale factor :
1. ResolutionScale.Scale100Percent:
2. ResolutionScale.Scale140Percent:
3. ResolutionScale.Scale180Percent:
Go through below useful links for more clarity:
https://invokeit.wordpress.com/2014/10/08/images-and-scaling-with-windows-runtime-winrt-wpdev-windev/
http://channel9.msdn.com/Events/Build/2014/3-541
EDIT:
var rawpixelperview = Windows.Graphics.Display.DisplayInformation.GetForCurrentView().RawPixelsPerViewPixel;
var Width = Convert.ToInt32(Window.Current.Bounds.Width * rawpixelperview);
var Height = Convert.ToInt32(Window.Current.Bounds.Height * rawpixelperview);
if(Width == 480 && Height == 800)
{
// logic here for this scale
}
else if((Width == 720 && Height == 1280 ) || (Width == 768 && Height == 1280))
{
// logic here for this scale
}
else
{
// logic here for this scale
}