Decompress images to use on a UITableView - iphone

Question

I currently working on a project that i need to display large images on a UITableView,this is very common problem for a lot of developers and learning with they threads i reached to the following procedure:
NOTE:The large images i refer,they all have 300x300px(600x600px,retina) and about 200kb,JPEG
Create a NSOperationQueue;
Download images asynchronously(Each image has 600x600px,corresponding to the #2x image);
Resize and create the non retina image(300x300px image);
Decompress both images;
Store all images on a NSCache;
After all that procedures have finished i update my UITableView on the main thread.I'am using a UITableViewCell subclass to draw all my needed content(As seen on Apple's sample codes).The main problem is that i'm confused about step 4(decompress images),my doubts:
NOTE:I'm currently storing my decompressed images on a NSCache.
Should i decompress the images and store then as UIImage's or NSData's?
How can i store the decompressed images?(NSCache,NSMutableArray...)
What is the best way to pass the decompressed image to my UITableViewCell subclass?
NOTE:I'm using the decompression code presented here:link

Answer 1

You can't really store an UIImage object to disk, but you can turn it to NSData using UIImagePNGRepresentation
Using UIImage will give you cache out of the box, I bet it's the most efficient you can get
Just put the image into UIImageView, Apple spent a lot of time on making image rendering fast.
That said, your images are not particularly big, especially for retina devices, I would advice looking at something like AFNetworking library that has a complete and tested solution for this problem.
Plus, you can look up the code of AFImageRequestOperation which does exactly what you need: download, store, cache, reuse.