Function parallel_preprocess_result 

pub fn parallel_preprocess_result<F, E>(
    images: Vec<DynamicImage>,
    preprocess_fn: F,
) -> Vec<Result<DynamicImage, E>>
where
    F: Fn(DynamicImage) -> Result<DynamicImage, E> + Sync + Send,
    E: Send,

Parallel processing with error handling