What image resolution can/should be used as the icon.png file for an iphone app? I know the size is 57 x 57 but what about the resolution? Links to specific documentation relating to iphone app icon design would also be helpful.
Great links RRUZ, thanks.
RexOnRoids
2009-09-03 08:23:42
+11
A:
Resolution only matters when you are trying to match the size of an image across multiple devices (print, screen, etc)
App icons are always 57x57 and will display without any scaling thus resolution doesn't matter (you could save it as 72dpi, 65535dpi or missing the dpi metadata entirely--SpringBoard won't care and will draw it the same in all three cases)
rpetrich
2009-09-03 03:36:11
Interesting answer, thanks. I used 150 dpi and it looks much crisper than 72.
RexOnRoids
2009-09-03 08:22:36
This answer is totally incorrect. Resolution absolutely matters - just think of the technicalities of it. 57x57 is a total of 3,249 pixels. It will look right at 72 dpi when displayed over 57x57 area. But at 326ppi (iPhone4) resolution, that same 57x57 area is now actually 228x228, so those 3,249 pixels are being stretched out to now cover an area of 12,996 total pixels. Do you see the discrepancy? (*NOTE - the discrepancy is all only because of iPhone 4's new higher resolution)
JAG2007
2010-10-08 04:23:42
My point is that iOS only cares about the pixel dimensions, not the physical dimensions or DPI resolution. Provide separate images for each size Apple has specified and you'll be fine (sizes range from 29x29 through 512x512)
rpetrich
2010-10-08 20:15:01
@JAG2007 - All that we care about is pixel dimensions, so he is correct. You just need to follow Apple's guidelines and provide correctly pixel sized raster graphics for each device and interface element: http://developer.apple.com/library/ios/#qa/qa2010/qa1686.html
Brad Larson
2010-10-09 16:49:26
+1
A:
I have had the best luck submitting to the App Store with 72dip, 57x57 icons.
jbrennan
2009-09-03 03:38:43
A:
If creating new images for the iPhone work with the image size in pixels i.e. 57 x 57 for icons. If you work with image sizes set in millimetres or inches, you'll find that 10mm on your monitor equates to only 4.4mm on the iPhone. The iPhone resolution is 163ppi which is over twice (2.25) the 72dpi resolution of a normal monitor. There is another good reason for the question, in that you may need to provide larger images for marketing (websites, blogs, banner ads, or even printed material) requiring zoomed in images that remain super sharp. In these general wider use cases I prefer to work at 300 dpi at the largest target size and then resize/resample image and resolution when done.
A:
57 x 57 and Apple takes care of the rest. Apple suggests that you have larger, more detailed graphics for, in the event, that your app gets selected as a feature app.
mobibob
2010-01-02 02:24:06
A:
57x57, as said.
You can chosse by code if let Apple to add the "shiny effect" or if you'll do (or not) it by yourself
and if you wonder again about iPhone icon size: http://www.iphoneiconsize.com
iPhoneManned
2010-06-27 18:05:57