Lag in UITableView scroll when image is loaded from document directory - iphone

Question

I have a UITableView which shows Items with images and their name. The problem is that the scroll's lagging because of the loading of the images for each cell.
This is how I am saving the images captured from the iPhone Camera and resized to 320 by 480.
- (void)saveImage: (UIImage*)image{
if (image != nil)
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *imageName = [NSString stringWithFormat: #"image_%#.png",[NSDate date]];
item.imageName = imageName;
NSString* path = [documentsDirectory stringByAppendingPathComponent:
imageName];
NSLog(#"%#",path);
NSData* data = UIImagePNGRepresentation(image);
[data writeToFile:path atomically:YES];
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
[userDefaults setInteger:[image imageOrientation] forKey:#"kImageOrientation"];
} }
This is how I am resizing it
- (UIImage *)resizeImage:(UIImage*)image newSize:(CGSize)newSize {
CGRect newRect = CGRectIntegral(CGRectMake(0, 0, newSize.width, newSize.height));
CGImageRef imageRef = image.CGImage;
UIGraphicsBeginImageContextWithOptions(newSize, NO, 0);
CGContextRef context = UIGraphicsGetCurrentContext();
// Set the quality level to use when rescaling
CGContextSetInterpolationQuality(context, kCGInterpolationHigh);
CGAffineTransform flipVertical = CGAffineTransformMake(1, 0, 0, -1, 0, newSize.height);
CGContextConcatCTM(context, flipVertical);
// Draw into the context; this scales the image
CGContextDrawImage(context, newRect, imageRef);
// Get the resized image from the context and a UIImage
CGImageRef newImageRef = CGBitmapContextCreateImage(context);
UIImage *newImage = [UIImage imageWithCGImage:newImageRef];
CGImageRelease(newImageRef);
UIGraphicsEndImageContext();
return newImage;}
And this is how I am loading them in cellForRowAtIndexPath
- (UIImage*)loadImage:(NSString *) imageName{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString* path = [documentsDirectory stringByAppendingPathComponent:
[NSString stringWithString: imageName]];
UIImage* image = [UIImage imageWithContentsOfFile:path];
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
UIImage *orientedImage= [UIImage imageWithCGImage: image.CGImage scale:1.0 orientation: [userDefaults integerForKey:#"kImageOrientation"]];
return orientedImage;}
One approach I was thinking of is to have an NSMutableArray with the UIImages loaded in it once and then fetching the images from there. The problem with that approach is that not all cells will have images so say there are 10 cells but only three images in the last 3 cells, the NSMutableArray approach will be a problem here because the images added will be at the indices 0,1,2.
I have one more solution in my mind which I would like to highlight here for you experts to verify if it will work. I actually am using CoreData and have generated the Model for the Item. If I was to manually add a UIImage field in this class and save the image to them objects, will that work or would it be wrong to do that?