Function palette_from_histogram

src/quant.rs:457–464

(hist: &HistogramInternal, max_colors: PalLen)

#[cold]
fn palette_from_histogram(hist: &HistogramInternal, max_colors: PalLen) -> (PalF, Option<f64>) {
    let mut hist_pal = PalF::new();
    for item in hist.items.iter() {
        hist_pal.push(item.color, PalPop::new(item.perceptual_weight));
    }

    (hist_pal.with_fixed_colors(max_colors, &hist.fixed_colors), Some(0.))
}

pub(crate) fn quality_to_mse(quality: u8) -> f64 {
    if quality == 0 {