Question

Interesting one this. I did do a bit Googling on the it but here we go. I have this png file. What I want to do is have it on my iPhone and send it to a server application on Windows. I use something like this:

NSString *filePath = [[NSBundle mainBundle] pathForResource:IconFile ofType:@"png"]; 

NSData *icon = [[NSData alloc ] initWithContentsOfFile:filePath];             
NSLog(@"File path is %@",filePath);
NSLog(@" Bytes to send in Icon File %d",icon.length);

Now this works just fine when I am on the iPhone simulator. When I go to the device though the png format grows in size. For example I had one that was 2514 bytes and went up to 2652 bytes. When I transmit this file – its not able to be read by the Windows app.

So I assume that when a png file gets copied over in the resource bundle – it must get optimised or something. I can get round it by changing the extension to say .txt – then the file doesnt change.

Does anyone know why that is ? And can you prevent it being changed as I’d rather keep the correct extension. I have seen that png formats need to be converted when you get them from the iPhone but I dont know why this would happen when you upload one and it doesn’t work in the simulator mode. Happens with both iPhone and iPad at iOS 5.

Answer 1

The modifying of the png images can be prevented in the build settings – under Packaging there is an option to compress PNG files:

Setting this to NO should solve your problem.