sequencing image using core animation, Recieving memory warnings

Question

I am recieving memory warning using 100 of animating images so I tried to use Core Animation instead but that gives me the same problem. This is because I don't know how to use replaceSublayer in my current code

UIView* upwardView=[[UIView alloc]init];
[upwardView setFrame:CGRectMake(0, 0, 1024, 768)];
[self.view addSubview:upwardView];

NSArray *animationImages=[NSArray arrayWithObjects:[UIImage imageNamed:@"001.png"],[UIImage imageNamed:@"001.png"],[UIImage imageNamed:@"002.png"],[UIImage imageNamed:@"003.png"],....,nil];

CAKeyframeAnimation *animationSequence = [CAKeyframeAnimation animationWithKeyPath: @"contents"];
animationSequence.calculationMode = kCAAnimationLinear;
animationSequence.autoreverses = YES;
animationSequence.duration = 5.00;
animationSequence.repeatCount = HUGE_VALF;

NSMutableArray *animationSequenceArray = [[NSMutableArray alloc] init];
for (UIImage *image in animationImages)
{
    [animationSequenceArray addObject:(id)image.CGImage];
}
CALayer *layer = [upwardView layer];
animationSequence.values = animationSequenceArray;
[layer addAnimation:animationSequence forKey:@"contents"];