Q:

Converting UIImage image representation

I am getting an UIImage from UIGraphicsGetImageFromCurrentImageContext, but they are very heavyweight memory wise. 
    UIGraphicsBeginImageContext([self bounds].size);
// CGContext procedures
    _cacheImage = UIGraphicsGetImageFromCurrentImageContext();

the size of the image is almost as the size of the iPad screen, (a little smaller), and when I  do something like this:
NSData *data = UIImagePNGRepresentation(_cacheImage)
NSLog(@"%i", data.lenght); 

It gives me like 700,000 in lenght.  I'm guessing its a .7MB file? 
Anyway if there is some way to reduce the image size, please let me know. 

A:

If you wish to reduce quality, try using 
NSData * UIImageJPEGRepresentation (
   UIImage *image,
   CGFloat compressionQuality
);

Pass compressionQuality == 0.0 for maximum quality or compressionQuality == 1.0 for maximum compression.