ios - What should image sizes be at @1x, @2x and @3x in Xcode?

Question

For example, I have a 100*100 size imageview or button, and I want to set its image or backgroundImage with a local .png file. Based on my understanding, I need to create 3 sets of images, i.e. 100*100 for @1x, 200*200 for @2x, 300*300 for @3x. I am not sure if my understanding is correct or not, can anyone help?

Answer 1

According to my understanding, if the image size is 100 * 100

@1x -> 100 * 100

@2x -> 200 * 200

@3x -> 300 * 300

There is something to understand. By creating 2x and 3x images, you can't expect exact same layout from each iPhone screen. The layout will be different from screen to screen. 1x, 2x and 3x image sizes dealing with only the pixel density of the screen.

Suppose you have an image which is 320 * 70 and you are creating

@1x -> 320 * 70

@2x -> 640 * 140

@3x -> 960 * 210

This will be your output in different screens.