Perhaps you are getting tired of me starting new threads. However, I thought I should just start a new topic, since this has nothing to do with memory management. It's more like performance and optimization methods. I am still building image Filterizer as an exercise. However, I am not using the same approach, so you may need to redownload the project. I am using a filter in core image called Disk Blur. I apply the filter onto the image, using a value above 20, and it is SLOW. That's ok, if it's a heavy filter. But when I try to scroll the or resize the window, it really is slow, as if it applies the same filter over and over again. Can you tell me why is this happening? I thought that when I applied the filter to the image and made that image my main image to be drawn, I avoided forcing the processor to reapply the filters, thus saving memory, and processor resources. However, I see that this isn't the case. Here is the project. Any recommendations?