Try this:
- (UIImage *)squareImageFromImage:(UIImage *)image scaledToSize:(CGFloat)newSize {
CGAffineTransform scaleTransform;
CGPoint origin;
if (image.size.width > image.size.height) {
CGFloat scaleRatio = newSize / image.size.height;
scaleTransform = CGAffineTransformMakeScale(scaleRatio, scaleRatio);
origin = CGPointMake(-(image.size.width - image.size.height) / 2.0f, 0);
} else {
CGFloat scaleRatio = newSize / image.size.width;
scaleTransform = CGAffineTransformMakeScale(scaleRatio, scaleRatio);
origin = CGPointMake(0, -(image.size.height - image.size.width) / 2.0f);
}
CGSize size = CGSizeMake(newSize, newSize);
if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(size, YES, 0);
} else {
UIGraphicsBeginImageContext(size);
}
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextConcatCTM(context, scaleTransform);
[image drawAtPoint:origin];
image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}