iOS: Save an image file to the Documents directory

save-image.m

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0]; //Get the docs directory
NSString *filePath = [documentsPath stringByAppendingPathComponent:@"image.jpg"]; //Add the file name
[((Image *)obj).scaledImage writeToFile:filePath atomically:YES]; //Write the file

//
// retrieve the image
//
NSData *pngData = [NSData dataWithContentsOfFile:filePath];
UIImage *image = [UIImage imageWithData:pngData];