How to support both iPad and iPhone retina graphics in universal apps

Question

Apple presented new iPad that support retina graphics.

I saw this link retina graphic in apple apps. As you can see apple just use "@2x" suffix for retina iPad display.

I have an universal app. So how to support retina in new iPad and iPhone? Will iPad retina use suffix "@2x" similar to iPad?

Solution 1

I just created a test app and tested.

So for devices without retina:
ImageName.png - For iPhone/iPod
ImageName~ipad.png -- For iPad

For devices with retina display:
[email protected] - For iPhone/iPod
ImageName@2x~ipad.png -- For iPad

And you can still use @2x if your iPhone high resolution image and iPad high resolution image have the same size.
To load the image just use [UIImage imageNamed:@"ImageName.png"];
I just tested it on iOS simulator for iOS 5.1, 5.0 and 4.3.
By the way why you should use @2x and nothing more.

The main thing because you shouldn't use the same graphics on iPhone and iPad, because iPhone and iPad has different size. And if you will use the same size the graphics will already done for you iPad retina display (if you previously use iPhone retina display). If you will images with different size, so you will use different image names for iPhone and iPad. So in this side you need just add @2x suffix. That's why you should use just @2x suffix. - these are my thoughts.

Solution 2

I found that the iPad mini/non retina iPad hardware, not simulator, would fall back on ImageName.png, not ImageName~ipad.png as you would expect from rowwingman's answer.

Looking at the docs, referenced in another StackOverflow question by Nate, it seems as though appending the device to iphone images is the correct way to do it.

MyImage.png - Default version of an image resource.

[email protected] - High-resolution version of an image resource for devices with Retina displays.

MyImage~iphone.png - Version of an image for iPhone and iPod touch.

MyImage@2x~iphone.png - High-resolution version of an image for iPhone and iPod touch devices with Retina displays.

Image, Sound, and Video Resources

Comments

[LightMan]

Be careful with the case of the letter P, I had problems because of writing ~iPad or ~iPhone, strangely it works with the simulator but not with the real device. Furthermore, I have discovered that if you don't have a @2x~ipad version then the new iPad will use the @2x version, which in this case is the iPhone retina file. Take also this into account...

[Matt]

The simulator isn't case sensitive (a common cause of problems when first distributing to device) thats why it works on simulator regardless of casing

[Ben Flynn]

The doc for this: developer.apple.com/library/ios/#documentation/2DDrawing/…

[Zev Eisenberg]

New link for the docs: developer.apple.com/library/ios/documentation/2DDrawing/…

[Isuru]

I have a question about the iPhone 5 display. The suffix -568h I use to name the launch image for the iPhone 5, do I have to add the same suffix for all the images that are used in the app also?

[rowwingman]

suffix -568h works only for launch image, but doesn't work for other images. You need to check device size.

[Isuru]

I see. Thank you. One last question, If I only provide images created for retina displays in an app, will it scale them down properly when the app runs on a non-retina display?

[rowwingman]

Yes, iOS will scale it, but I think that Apple could reject you app, because you need provide images for retina displays and non-retina. But I know some developers that post without non-retina images and Apple accept their apps.

[Abizern]

If you put the .png on the end of the file name, this doesn't work.