using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using bbiwarg.Images;

using Emgu.CV;
using Emgu.CV.Structure;
using Emgu.CV.VideoSurveillance;

namespace bbiwarg.Preprocessing
{
    class BackgroundSubtractor
    {
        private BackgroundSubtractorMOG subtractor;

        public BackgroundSubtractor()
        {
            subtractor = new BackgroundSubtractorMOG(0, 0, 0.0, 0.0); // defaults
        }

        public void update(Image<Bgr, byte> currentColorImage)
        {
            subtractor.Update(currentColorImage);
        }

        public Image<Gray, short> getForeground(Image<Gray, short> image)
        {
            Image<Gray, short> foreground = image.Clone();
            foreground = foreground.And(subtractor.ForegroundMask.Convert<short>(delegate(byte b) { if (b == 0) return 0; else return short.MaxValue; }));

            int numNonZero = 0;
            for (int i = 0; i < image.Width; ++i)
                for (int j = 0; j < image.Height; ++j)
                    if (subtractor.ForegroundMask.Data[j, i, 0] != 0)
                        ++numNonZero;
            Console.WriteLine("non zero: " + numNonZero);

            return subtractor.ForegroundMask.Convert<short>(delegate(byte b) { return (b == 0) ? (short) 0 : (short) 100; });
        }
    }
}