Method init_posterize_bits

src/hist.rs:236–248

optionallys et

(&mut self, posterize_bits: u8)

    /// optionallys et
    fn init_posterize_bits(&mut self, posterize_bits: u8) {
        if self.posterize_bits >= posterize_bits {
            return;
        }
        self.posterize_bits = posterize_bits;
        let new_posterize_mask = self.posterize_mask();

        let new_size = (self.hashmap.len() / 3).max(self.hashmap.capacity() / 5);
        let old_hashmap = std::mem::replace(&mut self.hashmap, HashMap::with_capacity_and_hasher(new_size, U32Hasher(0)));
        self.hashmap.extend(old_hashmap.into_iter().map(move |(k, v)| {
            (k & new_posterize_mask, v)
        }));
    }

    pub(crate) fn add_pixel_rows(&mut self, image: &DynamicRows<'_, '_>, importance_map: Option<&[u8]>, posterize_bits: u8) -> Result<(), Error> {
        let width = image.width as usize;