My First Cocoa Program newbie

I need some help understanding what im doing wrong here. The following program consumes all my memory. The point of the program is simple. It reads the DateTimeOriginal Exif tag from all the images in ~/Pictures/. Recursively!

Any help would be welcome thanks.

NSString* getDateTimeOriginal(NSString *path){
  [path retain];
  NSData  *imageData = [[NSData alloc] initWithContentsOfFile:path];
  [path release];


  CGImageSourceRef imageSource = CGImageSourceCreateWithData((CFDataRef)imageData, NULL);
  CFDictionaryRef properties   = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, NULL);

  [properties autorelease];

  [imageData release];

  NSString *e = @"{Exif}";
  [e autorelease];

  if(!CFDictionaryContainsKey(properties, e))
      return @"";

 
  CFDictionaryRef exif = CFDictionaryGetValue(properties, e);

   [exif autorelease];

 
  NSString *d = @"DateTimeOriginal";
   [d autorelease];

  if(!CFDictionaryContainsKey(exif, d))
     return @"";

  NSString *dateTimeOriginal = CFDictionaryGetValue(exif, d);

   [dateTimeOriginal autorelease];

  return dateTimeOriginal;
}


int main(int argc, char *argv[]){
  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

  NSFileManager *fm = [[NSFileManager alloc] init];

  NSArray *dc = [fm subpathsOfDirectoryAtPath: @"/Users/abo/Pictures/" error: NULL];

  [fm release];

  NSPredicate *regex = [NSPredicate predicateWithFormat: @"SELF MATCHES %@ OR SELF MATCHES %@ OR SELF MATCHES %@", @".+\.[nN][eE][fF]$", @".+\.[jJ][pP][eE][gG]$", @".+\.[jJ][pP][gG]$"];

  for(NSString *f in dc){
     if([regex evaluateWithObject:f]){
        NSString *path = [[NSString alloc] initWithFormat: @"%@%@", @"/Users/abo/Pictures/", f];
        NSString *result = getDateTimeOriginal(path);
         NSLog(@"%@ = %@", path, result);
         [result release];
         [path release];
        [f release];
     }
  }

  [regex release];

  [dc release];

  return 0;
}