Different image sizes for iOS development - ios

According to this link, would I need four different version of the same image size? Originally, I only created one for the iPhone 5, and I used the autosizing feature on storybuilder to resize the image correctly on iPhone 4s and below.

Concerning the four resolutions (***#2x.png): As it is described in https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/IconMatrix.html#//apple_ref/doc/uid/TP40006556-CH27-SW1 you have to resize some images, for example the App Icon has to be high- and low-resolution,
If you need to support standard-resolution iPhone or iPod touch devices
(Source: https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/IconMatrix.html#//apple_ref/doc/uid/TP40006556-CH27-SW1)
For the other Images, it is not necessary, but as "ta.speot.is" described in https://stackoverflow.com/a/12549329/1113407 it is better if you do it yourself.
And "JustSid" comment
Why should already slow devices do even more work?
(Source: https://stackoverflow.com/a/12549329/1113407)
put it straight: The older devices which do not support retina display are slower and at most times (own experience) your app won't run fluently on those if you do not prepare the app.
Concerning the iPhone 5 vs iPhone 4S:
You need some images in both heights, as it is mention in https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/IconMatrix.html#//apple_ref/doc/uid/TP40006556-CH27-SW1.
As the iPhone 4S has got the Apple A5-Chip and doesn't have to resize the image, as it has got an retina display, other images don't have to be resized. Therefor you could use the storybuilder-feature... But you have to ask yourself if the app should run on an older, non ratina display device...

Related

iOS app release, image resolutions

I have a simple, single view iOS app. I have an image which is to be used as the full background. Currently, i have edited the image for both portrait & landscape, in standard (414 X 736) & retina (1242 X 2208) for iPhone 6.
When i use iOS simulator, the background appears fine in all of the devices (4s > 6 plus). However i'm unsure about if this will hold out when launched/released.
Do i need to provide the image in all different resolutions for each device in my final app?
e.g imagePortrait4s.png, imagePortrait5.png, imagePortrait6.png, imagePortrait6plus.png etc
Since your image needs to be the same size as a launch image, your best bet is following the requirements for those: iOS Human Interface Guidelines - Icon and Image Sizes
Since the documentation does not state that providing the larger images for the iPhone 6 is sufficient to provide a good launch image for older phones, assume you need a 640 x 960 image for the iPhone 4s.

iOS - blur and buggy retina graphics on older devices running iOS7

I have been developing an app for iPad and was testing i on iPad 3 and iPad air with no problems at all. When i tried same app on iPad 2 the images were blur and some of them were not displaying properly even some were half visible half not visible.
As per my knowing the iOS7 only apps do not need non-retina graphics so i am using only Retina Graphics. So i tried using Asset Catalog too but same was the result.
Strangely when i use image#2x.png in xib it displays fine but do not show image in xib and when i use image.png it is displayed in xib but same issue when run on the device.
What i need to do to show images in xib too and would run fine on device?
Fisrt You MUST provide non-retina graphics in the asset catalog. You should understand that bigger images on old devices provides bigger memory and performance impacts.
You must pay attention also on odd measure, because if some geometric frames calculation results in decimal point such as 23.5 1.5 you are going to have antialiased elements in your interfaces.
You can avoid that wrapping frames into CGRectIntegral.

ios, publish different build per device

Google Play allows different apks per screen density, does Apple Store support this?
I'm sure the info is somewhere, but all I find when I search are people asking how to develop one app to support all devices.
I know how to do that already, but this specific (top secret) project will be 1000 times better if I can release one super optimized version for each screen resolution... but I'll settle for density or device (generation and type) if needed.
I don't have access to XCode (no Mac) to check options currently.
Bonus points: If possible, is Apple going to frown on this and possibly reject my app because of this?
This can't be done. If your app supports the iPhone then it must support both 4" and 3.5" inch iPhones. If it supports only iOS 7 then you can avoid non-retina devices because only retina devices can run iOS 7.
But if you support the iPad you must support both retina and non-retina.
You can have one app (Universal) that does it all or you can have separate iPhone and separate iPad apps. But the iPhone app must support both sizes and possibly both types (retina and non-retina) of screens. And the iPad app must support both types of screens.
Apple won't accept apps that don't support the differences.
It should also be pointed out that in the Interface Builder part of Xcode, you setup the UI with points and not pixels. So, for an iPad, when you place a button, you do not have to specify retina or not. On a Retina screen a point is 2x2 pixels and on a non-retina screen a point is 1x1 pixels. Also, with image assets, you have a single image asset you ask for in code, but you add multiple copies of the image in the image assets. Like the retina and non-retina copies. If you have an image named cat.png, for retina this would be cat#2x.png and for non-retina it would be cat.png. But, in code or the inspector you would reference it with imageNamed:#"cat" and Objective-C is designed to handle the rest.

Necessary to have Retina and non-Retina for all images in iOS App?

Currently , all the UIImageViews in my app are set to scaleToFill mode, using only one retina image without setting any non-retina image. I suppose that on non-retina display, the extra resolution will be lost by itself.
Question: Is this approach acceptable? And will Apple disapprove my app due to the missing non-retina images for UIImageView?
Apple won't reject your app. However it's recommended to have non-retina versions if you're targeting Universal devices, since there are still lot of non-retina iPad out there, and scaling is slower and sometimes produces ugly images.
If you're targeting iPhone only, (IMO) there's no need for non-retina images.

What resolution do I need to make images for universal iOS apps in?

I am making a Universal app on xCode 4.4, using Storyboards. I am making the images for this app in Photoshop. I want to make a background image that fills the whole screen.
What I want to know is:
What resolution do I make the images?
Do I need 1 for iPad and 1 for iPhone, or more?
How do you make it work with the iPhone 5 as well?
You might need up to 10 background images:
There's the retina iPad: 2048x1536, non retina iPad and iPad Mini: 1024x768, retina iPhone: 640x960, non-retina iPhone: 320x480 and the new iPhone 5 (retina only): 640x1136.
That's 5. If you want to support both landscape and portrait, then you have 10 combinations.
PS: If you decide to keep the status bar visible (as most apps do), then reduce the height with 20 pixels (40 pixels for retina displays). That's how much room is needed for the status bar.
You should consider the approach of using only one image. The user experience of most apps is poor if you dont respect the available canvas size.
And you might want to focus special areas of your artwork to the user.
I would propose you to implement different scenarios at least for iPad and iPhone.
The resolution itself is described within the specs. So use one for iPhone and one for iPad, the different logos are posted in two resolution, with a postfix #2x or for the new Appstore dimensions with another prefix, but all these details are within the specs.
My experience is that in most cases you have to organise the user interface separately in order to provide a good user experience.

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