I want to add high res images in my iOS4 app. I already read this http://developer.apple.com/iphone/library/documentation/iphone/conceptual/iphoneosprogrammingguide/SupportingResolutionIndependence/SupportingResolutionIndependence.html#//apple_ref/doc/uid/TP40007072-CH10-SW2 and a lot of other pages but I did not find the answer which ppi my image should have.
Currently, I have an image for example button.png with 160ppi and 50x30px. Now I want to create a high res image named email@example.com. Is it correct to use 326ppi and 100x60px?
I already had a look at other iOS open source apps but each app did it on a different way. Most apps used 72ppi for normal and high res. What is correct?
Thanks for your answers
To be quite frank, I've not found a need to adjust pixel resolution for my images (i.e. I leave my Photoshop templates at 72 ppi and they're OK). If you just provide the correct dimensions for each format, the system will know how to deal with your images appropriately depending on the resolution of the device it's on.