Take the 2-minute tour ×
Graphic Design Stack Exchange is a question and answer site for Graphic Design professionals, students, and enthusiasts. It's 100% free, no registration required.

I'm creating buttons for my app specifically for the iPhone 4S and the iPhone5. For some reason, any objects that are circular in nature appear jagged on the phones. For example, a location marker which I created in Photoshop doesn't look jagged from within Photoshop. However, when exported as a .png and used as a button in iOS, the edges around the curve of the location marker are jagged. Is this a problem with the resolution?

share|improve this question
4  
If possible, a screenshot of how it looks in Photoshop and including the output image in your post would improve your question greatly! –  JohnB Jun 27 '13 at 16:16
1  
Agree with @JohnB, can we have a screenshot? Another question is are the iPhones using Retina display? Remember that when designing for retina, the sizes are double. So if you're image is too small it will be scaled up, thus the jagged look. –  ckpepper02 Jun 27 '13 at 17:27
    
Is it sized in the app actual size? –  DA01 Jun 27 '13 at 19:05
    
Three things: 1) You should be using illustrator for buttons, since it's vector artwork and, I'm assuming, doesn't have any images in it. But that won't fix your problem 2) Does the png file you export have jagged edges or only when it's imported. 3) I would guess that it's a resolution problem, either with how you're exporting it as a png (unlikely) or how you're importing it into xcode (likely) –  Mike G Jun 27 '13 at 19:10

1 Answer 1

I'll take a guess that you're exporting as PNG-8 with a small number of colors, which chops off any pixels below a certain transparency and leaves the resulting image strongly aliased (the technical term for "jagged"). PNG-8 only has one level of transparency; it's an all-or-nothing proposition, but using a high value for the number of colors can give an acceptable result, depending on the background.

Use PNG-24 to achieve smooth anti-aliasing. This is what is recommended in the Apple iOS Human Interface Guidelines.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.