将许多UIImage保存到NSMutableArray中，没有内存泄漏或类似的方法

I am trying to do screen capturing and saving many images into NSMutableArray. Then, I will call those images and make video. I can successfully make video. However, the problem is that I can't save many images into NSMutableArray. The application crash. I would like to know how to save those images temporarily. (not in document directory).I am trying to do screen capturing and saving m