Obtain raw image data from an iOS user's photo library

iOS raw image data

- (void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    NSURL *assetURL = info[UIImagePickerControllerReferenceURL];
    ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init];
    
    [assetLibrary assetForURL:assetURL resultBlock:^(ALAsset *asset) {
        ALAssetRepresentation *representation = [asset defaultRepresentation];

        Byte *buffer = (Byte *)malloc(representation.size);
        NSError *error = nil;
        NSUInteger size = [representation getBytes:buffer
                                        fromOffset:0
                                            length:representation.size
                                             error:&error];
        
        if (size == 0) {
            NSLog(@"Could not get asset data");
            return;
        }

        NSData *imageData = [NSData dataWithBytesNoCopy:buffer length:size];

        // todo: upload data to server

    } failureBlock:^(NSError *error) {
        NSLog(@"Could not get asset");
    }];
}