The most efficient way of adding "AppIcon" to project in Xcode? - ios

Question

Im programming an app in xcode and something has recently come to my attention when designing app icons. Here is the current setup that I have in my project:
Right now I have a 87x87pixel image for the "29pt" option (far left of the image), I also have a 120x120 for the 40pt option(middle) and I have a 180x180 pixel png for the 60pt option(far right). This seems highly inefficient, not only this but I need to supply #2 resolution images too? Surely there is a better way of doing this?

Answer 1

There are a couple of approaches I've taken in the past. One way is to create your icons, etc. in GIMP, Photoshop, etc. If you need to resize them, there's a command line utility called ImageMagick which I find to be a lot easier for resizing images than setting sizes in an image editor. The command you would use for resizing is called mogrify.
Option two is to get your hands on an app called Asset Catalog Generator. You just dump your images in and it spits out the correct file sizes and naming conventions. It's probably the best $4.99 I've spent in a long time.
Update
It appears someone has written a script to create the icons, too. I haven't used it myself, so you might want to poke around and look for others.

Answer 2

Create your app icon (once) at a decent resolution say 1024x1024. Drop the file into MakeAppIcon (a free service) and out pops all your icons in a zip file properly sized, enhanced as necessary, and rendered. Just drop them into images.xcassets and you're done. This avoids having to tweak any icons that may be off by a pixel or two and avoids those annoying Xcode warning messages.This vendor also offer a service for bulk uploading your iTunes screenshots, but I haven't tried that yet. Luv it!

Answer 3

You can use the vector-based images from a PDF. Session 411 from WWDC “What’s New in Interface Builder” discussed—albeit very briefly—Xcode’s support for creating your PNG files at build time from a vectorised PDF.
There is good article on this, you can refer that as well. http://martiancraft.com/blog/2014/09/vector-images-xcode6/
(Note that this does NOT cover PDFs for icons, just for images)

Answer 4

I would suggest you try SquareIcon, which I believe makes creating Xcode app icon sets very easy. Just to let you know, this is my own app.
The app allows you to drop in a generic image file (like a JPG or PNG) and convert it to a .appiconset file which you can put into your project's asset catalog. This takes care of all the naming and resizing that you might have to do manually.

Answer 5

UPDATE 2: I might've misunderstood you. When I wrote this answer, I thought that by 'inefficiency' you meant memory consumption and the resulting app size. If you meant, that making an icon for all the sizes is a lot of work, and you're looking for a better way to do it, consider looking at Adrian B's answer instead.
First of all, no, there is no more efficient way of doing it (unfortunately). Xcode supports vector images, but they are only supported on OS X, AFAIK. On iOS it just generates all necessary images at compile time.
Second, the app icon is small. You won't save a lot of space by optimizing app icon size. If you need to decrease the app size, try finding something that really takes much space. The icon doesn't.
UPDATE: Luckily, Apple realizes, that forcing everybody to download resources that they don't need is no good. So they introduced App Thinning along with iOS 9. I haven't looked into it thoroughly yet, but the general idea is that you upload a binary containing all the resources as usual, but when your users download the app from the AppStore, they get a version containing only resources that they need.