FloydSteinbergDithering.cs

﻿/*
   This file implements error pushing of dithering via (Robert) Floyd and (Louis) Steinberg kernel.
   This is free and unencumbered software released into the public domain.
*/

public class FloydSteinbergDithering : DitheringBase
{
    public FloydSteinbergDithering(FindColor colorfunc) : base(colorfunc)
    {
        this.methodLongName = "Floyd-Steinberg";
        this.fileNameAddition = "_FS";
    }

    override protected void PushError(int x, int y, short[] quantError)
    {
        // Push error
        // 			X		7/16
        // 3/16		5/16	1/16

        int xMinusOne = x - 1;
        int xPlusOne = x + 1;
        int yPlusOne = y + 1;

        // Current row
        if (this.IsValidCoordinate(xPlusOne, y))
        {
            this.ModifyImageWithErrorAndMultiplier(xPlusOne, y, quantError, 7.0f / 16.0f);
        }

        // Next row
        if (this.IsValidCoordinate(xMinusOne, yPlusOne))
        {
            this.ModifyImageWithErrorAndMultiplier(xMinusOne, yPlusOne, quantError, 3.0f / 16.0f);
        }

        if (this.IsValidCoordinate(x, yPlusOne))
        {
            this.ModifyImageWithErrorAndMultiplier(x, yPlusOne, quantError, 5.0f / 16.0f);
        }

        if (this.IsValidCoordinate(xPlusOne, yPlusOne))
        {
            this.ModifyImageWithErrorAndMultiplier(xPlusOne, yPlusOne, quantError, 1.0f / 16.0f);
        }
    }
}