Crashing App when try to add images..?

I am new iPhone Developer. I am upgrading existing iPhone App. I am using Core Data Model to save data. In App, there is a 15 square boxes to add images. I am calling a Detached Thread to make a separate process. In this process, I am saving image into two size. I have added observer with image object and remove observer at last.

I am using this method to add Observer:-

[projectImage addObserver:self forKeyPath:@"fileName"开发者_开发问答 options:NSKeyValueObservingOptionNew context:nil];

And this method for making separate Thread:-

[NSThread detachNewThreadSelector:@selector(addImage:) toTarget:self withObject:[dic retain]];

here AddImage is Method like:-

- (void) addImage:(NSDictionary *) dic {
   NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
   UIImage *image = [dic objectForKey:@"image"];
   projectImage = nil;
   projectImage = [dic objectForKey:@"managedObject"];
   [projectImage importImageData:image];
   [projectImage removeObserver:self forKeyPath:@"fileName"];   
   [pool drain];   
}

And dic is Dictionary

My problem is : It is Crashing after taking 4-5 images by Camera or Phone library.

If any can guide me to get rid to this problem.

Thanks in Advance

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You are leaking memory, and probably because of this your app will crash. I think the app runs out of memory and gets killed.

remove the [dic retain] from

[NSThread detachNewThreadSelector:@selector(addImage:) toTarget:self withObject:[dic retain]];

the object is retained by the method call. See the discussion of detachNewThreadSelector:toTarget:withObject:.

The objects aTarget and anArgument are retained during the execution of the detached thread, then released. The detached thread is exited (using the exit class method) as soon as aTarget has completed executing the aSelector method.

your call should be

[NSThread detachNewThreadSelector:@selector(addImage:) toTarget:self withObject:dic];