Reloading UICollectionView With UIImages not Releasing Memory - ios

Question

I use the following code to create borders around images. I loop through the following multiple times to create thumbnail images with borders that are then placed in a UICollectionView.
The problem seems to be that every time I reload the UICollectionView the images are not being released from memory and it seems to build up to the point where it crashes. I don't think it is the UICollectionView code because If I run it with images that don't require a border I don't get any issues.
- (UIImage *)applyFrame:(UIImage *)image selectedFrame:(NSString *)selectedFrame {
UIImage *frame;
NSLog(#"Image Size For Frames: %f, %f",image.size.width,image.size.height);
if(image.size.width == image.size.height){
frame = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:[NSString stringWithFormat:#"%#-Square.png",selectedFrame] ofType:nil]];
}
if(image.size.width > image.size.height){
frame = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:[NSString stringWithFormat:#"%#.png",selectedFrame] ofType:nil]];
}
if(image.size.width < image.size.height){
frame = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:[NSString stringWithFormat:#"%#.png",selectedFrame] ofType:nil]];
frame = [self rotateUIImage:frame clockwise:true];
}
GPUImageAlphaBlendFilter *blendFilter = [[GPUImageAlphaBlendFilter alloc] init];
GPUImagePicture *imageToProcess = [[GPUImagePicture alloc] initWithImage:image];
GPUImagePicture *border = [[GPUImagePicture alloc] initWithImage:frame];
blendFilter.mix = 1.0f;
[imageToProcess addTarget:blendFilter];
[border processImage];
[border addTarget:blendFilter];
[imageToProcess processImage];
return [blendFilter imageFromCurrentlyProcessedOutput];
}
- (UIImage*)rotateUIImage:(UIImage*)sourceImage clockwise:(BOOL)clockwise {
CGSize size = sourceImage.size;
UIGraphicsBeginImageContext(CGSizeMake(size.height, size.width));
[[UIImage imageWithCGImage:[sourceImage CGImage] scale:1.0 orientation:clockwise ? UIImageOrientationRight : UIImageOrientationLeft] drawInRect:CGRectMake(0,0,size.height ,size.width)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}

Answer 1

UIImage imageWithContentsOfFile: returns an autorelease object, which will be released only when the app returns to the current run loop. So, might it be that you app loops for a long time executing this code? In this case, the autorelease objects might accumulate, and increase the heap usage.
If so, you could try to insert into the body of the responsible loop an autorelease block:
#autoreleasepool {
...your statements
}