Function compose

pub fn compose(
    dir: &str,
    algorithm: BlendAlgorithm,
    background: &Background,
    compression: CompressionType,
    filter: FilterType,
    benchmark: &mut Benchmark,
) -> Result<String, PConvertError>

Testing utility that composes an image made up of the specified background image, using the specified algorithm, compression and filter types. Looks for the layers and outputs the final composition to the given dir and takes track of times spent in each phase in the benchmark struct