gistfile1.txt

    println!("DEBUG PARAMS {:?}", params.as_ref().unwrap());
    println!("DEBUG DATA(len: {}): {:?}", out.len(), &out);

    assert!(out.len() % (columns+1) == 0);
    // Then unfilter (PNG)
    let input = out;
    let mut out = Vec::<u8>::new();
    out.resize(input.len() / (columns+1) * columns, 0); // One less byte per row

    if predictor > 10 {
        // Apply inverse predictor
        let null_vec = vec![0; columns];
        let mut prev_row: &[u8] = &null_vec;
        let mut i_in = 0;
        let mut i_out = 0;
        while i_in < input.len() {
            // +1 generally because the first byte on each row is predictor
            
            let predictor_nr = input[i_in];
            let row = &input[(i_in+1)..(i_in+1+columns)];
            let out_row = &mut out[(i_out)..(i_out+columns)];

            unfilter(PredictorType::from_u8(predictor_nr)?, n_components, prev_row, row, out_row);

            prev_row = &input[(i_in+1)..(i_in+1+columns)];

            i_in += columns + 1;
            i_out += columns;
        }
    }