Method target_mse

src/attr.rs:295–303

`max_mse`, `target_mse`, user asked for perfect quality

(&self, hist_items_len: usize)

    /// `max_mse`, `target_mse`, user asked for perfect quality
    pub(crate) fn target_mse(&self, hist_items_len: usize) -> (Option<f64>, f64, bool) {
        let max_mse = self.max_mse.map(|mse| mse * if hist_items_len <= MAX_COLORS { 0.33 } else { 1. });
        let aim_for_perfect_quality = self.target_mse == 0.;
        let mut target_mse = self.target_mse.max((f64::from(1 << self.min_posterization_output) / 1024.).powi(2));
        if let Some(max_mse) = max_mse {
            target_mse = target_mse.min(max_mse);
        }
        (max_mse, target_mse, aim_for_perfect_quality)
    }

    /// returns iterations, `iteration_limit`
    #[must_use]