Fitness Function

fitness.js

 /**
     * Fitness Function
     * fitness = 1 -    (Square of pixel difference between chromosome and reference Image)
     *                  ____________________________________________________________________
     *                  ( Resolution of the Image * count(RGBA) * Number of Possible Values)
     *
     * This fitness function stays inside [0,1]
     * */
    fitness(width,height){

        //Draw the Chromosome First
        this.draw(this.ctx,width,height);

        var fit = 0;

        var imagedata = this.ctx.getImageData(0,0,width,height).data;

        for (var i = 0; i < workingData.length;i++){

            var dist = workingData[i] - imagedata[i];

            fit += dist * dist;
        }

        this.fitnessValue = 1 - fit / (75 * 75 * 4 * 256 * 256);

        return this.fitnessValue;
    }
}