iPad: PNG Crush error

I am trying port my iPad project to latest iPad 2. I installed iOS 4.3 SDK with Xcode 4.0. When i try to build my project, i'm getting the following error. I don't know why am i getting this error. Could someone help me to resolve this build error?

While reading /Users/username/Desktop/iPAD/MyProject/trunk/Resourses/images/top_bar.png pngcrush caught libpng error: Not a PNG file..

Could not find file: /Users/username/Library/Developer/Xcode/DerivedData/Project-fmhveawksgdtnraclfizuhrekmzi/Build/Products/Debug-iphoneos/MyApp-Upgraded.app/top_bar.png

I had the same problem, but it wasn't because of a corrupted png : it was because two PNG files had the same filename in different directories of my source tree. What was peculiar was that the errors (I had 4 files which had "twins") were not identical from one build to another. On one run I had errors on all files, on the other only on some of them.

Did you check whether the file Users/kavapanga/Desktop/iPAD/ALN II 3 latest 2/trunk/Resourses/images/CS_logo_for_top_bar.png exists? Also check if it is infact a PNG file. Right click on the file and do a Get Info to check if the file has any other extension and is marked as hide extension. If you are not sure of the format of the file, opening the file and save it as a PNG file again should work ,most of the time.

I had the same problem. How to fix : Open up image with Preview -> File > Export > Format change to PNG and you are done !!

There is no issues with image or Xcode. The issue, which creating that image from photoshop, is whether that image is interlaced or not interlaced. While saving your image in photoshop you will get one option for that.

Check out this link for more info:

Build app with Xcode 4 - it always show some error about PNG image

not interlaced: You should use image which is not interlaced. This is the original png image.

interlaced: This option is suitable for the image which are getting downloaded from web. Specifically saying, this is used when you require to reduce image load time. What this option internally does is, it will create a .png file but with lower clarity and lower dpi like a normal jpeg image. That's why such images are having property that it is jpeg image.

Hope this will help you all.

Enjoy Coding :)