Non retina images – must I add them to xcode? - ios

Because I made app (iphone) myself, with 200 images, I want not using non retina images.
It may be for me big problem to resize images for non retina display.
I don't have non retina display iphone, to test it.
Must I add non retina images to xcode, or not?
If I don’t add them, must I add “#2x” to all images for retina?
I tried my best to find answer for my question but there was no clear answer.
Thx for answers.
I thing it will be better make non retina display images, than buy non retina device for testing how it looks.
I have another question:
Button background needs #2x images and non retina display background images?

You must add non-retina images if the platform your targeting includes non retina devices (e.g. iOS 6 and earlier or iOS 7 iPad). If you do not, non-retina devices may not render your app correctly.
If you are not targeting a platform that supports non-retina devices (Eg iOS 7 iPhone), you may omit non-retina images. Your retina images will still need the "#2x" suffix in the file name for the system to find them.

I read somewhere that if you do not include non-retina images, the iOS will use the #2x images, scale them on the fly to non-retina sizes, but that may affect performance. Make sure you test on at least one non-retina Device to make sure it works.

This should not be too much of an issue. Test your app on the simulator using non retina and make sure your images are showing up properly. Your images should scale and won't cause a problem. It would be better if you could have both retina and non retina images but not a game beaker.

Related

iPhone 6+ images

I have a question that I need confirmation on. I know that the Apple Developer document shows App icon size at #3x
https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/IconMatrix.html.
Does this also apply to regular images that you use in your App? I just need to make 100 percent sure. The other stackoverflow answers I encountered just show App icon sizes, but doesn't address regular images that you use through out your App.
If you want your app to take full advantage of the Retina HD display then yes, you need to have all versions for all images used by your app, i.e. image.png, image#2x.png, image#3x.png.
Dont forget to setup launch screens for each iPhone size, or your bigger phones will just enlarge your app views without really using AutoLayout or using the high def images.
It doesn't apply for regular images that you use in you app. Make sure they are with good pixels.
Provide high-resolution (#2x) versions of all image assets.
Images that are not #2x will appear blurry on the Retina display.
source:
https://developer.apple.com/design/tips/

Is it possible to renderning non-retina image using retina image programmatically at runtime?

is it possible to render non-retina images using retina images programmatically at runtime?
I'm developing an universal App, and there are a lot of images in my app bundle, make my app bigger and bigger and I'm trying to downsize my app....
I can't just delete all non-retina images, cause I need to support iPad mini without retina display.
So is this possible? Using retina images to render a non-retina images, will this cause fatal performance issue? or any other side effects?
Thank you very much.
Edit1:
#troop231 Yes, the 1st generation iPad mini and 2ed generation iPad mini both supports retina assets
#bstahlhood I thought I was doing something wrong so the universal App on 1st gen iPad mini not using the #2x images, looks like this is just another limitation from Apple.
So I guess the only solution is not to support 1st gen iPad mini or I have to add both non-retina images and retina images in my App bundle?
Yes - but you need to specifically set the frame dimensions for the image in every case by the 1/2 size.
e.g. retina image is 100x100 so if you use it make sure it has CGSize(50,50)

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.

iPad image sizes

I am creating an application for iPad, the images I have available from graphic designer are
really big, almost twice the size.
According to the graphic designer, the images were created keeping in mind iPad 3.
So if I reduce my image size to half and use them, is it going to make any difference on iPad3?
Or there is no difference and it will be compatible in both.
I am new to iOS development and not sure about the image resizing in detail.
Thanks in advance.
You will have two versions of every image where one is double the size of the other and the operating system will decide which version to use. You just need to name the images correctly.
Images for ipad3 will have #2x within the name. Example
image.png <--- non retina ipad
image#2x.png <------ retina ipad (ipad3)
Here is a post explaining this more: Preparing your iPhone App for Higher Resolutions

Resources