gistfile1.txt

[self openPhotoAlbum];

- (void)openPhotoAlbum
{
 [[NSOperationQueue mainQueue] addOperationWithBlock:^{
            UIImagePickerController *controller = [[UIImagePickerController alloc] init];
            controller.delegate = self;
            controller.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
          
            [self presentViewController:controller animated:YES completion:NULL];
        }];
}
- (void) imagePickerController: (UIImagePickerController *) picker  didFinishPickingMediaWithInfo: (NSDictionary *) info
{
     NSString * mediaType = info[UIImagePickerControllerMediaType];
    NSLog(@"image==>>%@",mediaType);
    if([mediaType isEqualToString:(__bridge NSString *)kUTTypeImage])
    {
        NSLog(@"Image");
        JSQPhotoMediaItem *photoItem = [[JSQPhotoMediaItem alloc] initWithImage:[UIImage imageNamed:mediaType]];
        JSQMessage *photoMessage = [JSQMessage messageWithSenderId:kJSQDemoAvatarIdSquires
                                                       displayName:kJSQDemoAvatarDisplayNameSquires
                                                             media:photoItem];
        [_messages addObject:photoMessage];
      [self dismissViewControllerAnimated:picker completion:nil];
    }