Ideals Resolutions for Images in iPhone/iPad & iPhone(Retina)/iPad(Retina)

Question

Can someone tell me what the ideal resolution for images are for an iPhone/iPad and iPhone(Retina)/iPad(Retina). I have pulled these measurements off of the Apple Website and Wikipedia. See Below:

Regular iPhone 480 x 320 - 163 ppi

iPhone Retina Display 960 x 640 - 326 ppi.

iPad 2: 1024 x 768 - 132 ppi

iPad 3 (retina display): 2048 x 1536 - 264 ppi

Thank you would really appreciate for some assistance!

Answer 1

See this site for great information on designing for the Retina Display.

http://bjango.com/articles/designingforretina/

http://bjango.com/articles/designingforretina2/

Answer 2

Depends on how you are going to use them. But ideally your images would be exactly dimensioned for the displaying you are going to do.

Ideally if you wanted to display an image on an original iphone or iPad then you would have a 100 x 100 image for those devices and provide an "@2x" image that is 200 x 200 for display on the retina devices. if you put the devices up to one another, physically the images may look a bit different sized between the iPhones and the iPads as the DPI is different.

Alternatively you could essentially provide only a 2x image and have the lower end devices downscale the images!

Answer 3

    iPhone3        320x480  163 ppi
    iPhone4        640×960  326 ppi
    iPhone4S       640×960  326 ppi 
    iPhone5        640×1136 326 ppi 
    iPad          1024x768  132 ppi
    iPad2         1024x768  132 ppi
    iPad (3gen)   2048x1536 264 ppi
    iPad (4gen)   2048x1536 264 ppi
    iPad mini     1024x768  163 ppi