Directory Loading Time - objective-c

Question

One of the features of my application is to allow users to save images. These images are later presented in a detail view of a UITableView and in the cells of the UITableView. However, when returning to the page that is displaying the cells it takes a noticeably long time for it to load. I believe this is because the images are saved to the documents directory and every time the page loads they are reloaded from the directory. Should I be storing loading the images into an memory every time the application launches or am I way off in my theory. I have also tried compressing the images with the following code and it did not increase performance.
[[GTImageStore sharedStore] setImage:currentImage forKey:currentImageKey];
NSString *jpgName = [[NSString alloc] initWithFormat:#"Documents/%#.jpg", currentImageKey];
NSString *jpgPath = [NSHomeDirectory() stringByAppendingPathComponent:jpgName];
float scale;
if (currentImage.size.width < currentImage.size.height)
{
scale = 100/currentImage.size.width;
}
else if (currentImage.size.width > currentImage.size.height)
{
scale = 100/currentImage.size.height;
}
else
{
scale = 100/currentImage.size.width;
}
UIImage *image = [[UIImage alloc] initWithCGImage:currentImage.CGImage scale:scale orientation:[currentImage imageOrientation]];
[UIImageJPEGRepresentation(image, 0.5) writeToFile:jpgPath atomically:YES];
Any help is really appreciated! Thank you!
Code for adding cells:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UINib *giftCell = [UINib nibWithNibName:#"GiftCell" bundle:nil];
[tableView registerNib:giftCell forCellReuseIdentifier:#"UIGiftsTableCell"];
cell = [tableView dequeueReusableCellWithIdentifier:#"UIGiftsTableCell"];
if (!cell) {
cell = [[GTGiftCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:#"UIGiftsTableCell"];
}
// Determine gift at index path
GTGift *gift = (GTGift *)[[[GTGiftStore sharedStore] allGifts] objectAtIndex:[indexPath row]];
[[cell textLabel] setText:[gift name]];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateStyle:NSDateFormatterLongStyle];
NSString *subText = [[NSString alloc] initWithFormat:#"Purchased on %#", [formatter stringFromDate:[gift datePurchased]]];
[[cell subTextLabel] setText:subText];
[[cell detailTopTextLabel] setText:[[gift givingTo] name]];
[[cell detailMiddleTextLabel] setText:[[gift reasonFor] name]];
[[cell detailBottomTextLabel] setText:[[gift boughtFrom] name]];
NSString *jpgName = [[NSString alloc] initWithFormat:#"Documents/%#.jpg", [gift imageKey]];
NSString *jpgPath = [NSHomeDirectory() stringByAppendingPathComponent:jpgName];
UIImage *imageToLoad = [[UIImage alloc] initWithContentsOfFile:jpgPath];
[[[cell image] layer] setBorderColor:[[UIColor lightGrayColor] CGColor]];
[[[cell image] layer] setBorderWidth:1];
[[cell image] setClipsToBounds:YES];
[[cell image] setContentMode:UIViewContentModeScaleAspectFill];
[[cell image] setImage:imageToLoad];
return cell;
}
I have created a custom cell using a xib file with a viewController named GTGiftCell.

Answer 1

There are two approaches you can take
If your application needs to load the images as they change then you keep with loading the images as you are , but you should read apples Concurrency Programming Guide to improve performance if the images need to update and change w/o the user refreshing the view
Load your images when the application loads but once again to improve performance read the Concurrency Programming Guide