Accord.Imaging.Filters.WolfJolionThreshold.ProcessFilter C# (CSharp) Method

        protected override unsafe void ProcessFilter(UnmanagedImage sourceData, UnmanagedImage destinationData)
        {
            int width = sourceData.Width;
            int height = sourceData.Height;

            int pixelSize = System.Drawing.Image.GetPixelFormatSize(sourceData.PixelFormat) / 8;

            int srcStride = sourceData.Stride;
            int dstStride = destinationData.Stride;

            int srcOffset = srcStride - width * pixelSize;
            int dstOffset = dstStride - width * pixelSize;

            byte* src = (byte*)sourceData.ImageData.ToPointer();
            byte* dst = (byte*)destinationData.ImageData.ToPointer();

            // TODO: Move or cache the creation of those filters
            int[,] kernel = Accord.Math.Matrix.Create(radius * 2 + 1, radius * 2 + 1, 1);
            Convolution conv = new Convolution(kernel);
            FastVariance fv = new FastVariance(radius);

            // Mean filter
            UnmanagedImage mean = conv.Apply(sourceData);

            // Variance filter
            UnmanagedImage var = fv.Apply(sourceData);

            // do the processing job
            if (sourceData.PixelFormat == PixelFormat.Format8bppIndexed)
            {
                byte* srcVar = (byte*)var.ImageData.ToPointer();
                byte* srcMean = (byte*)mean.ImageData.ToPointer();

                // Store maximum value from variance.
                int maxV = Max(width, height, srcVar, srcOffset);

                // Store minimum value from image.
                int minG = Min(width, height, src, srcOffset);

                for (int y = 0; y < height; y++)
                {
                    for (int x = 0; x < width; x++, src++, srcMean++, srcVar++, dst++)
                    {
                        double mP = *srcMean;
                        double vP = *srcVar;

                        double threshold = (mP + k * ((Math.Sqrt(vP) / (double)maxV - 1.0) * (mP - (double)minG)));

                        *dst = (byte)(*src > threshold ? 255 : 0);
                    }

                    src += srcOffset;
                    srcMean += srcOffset;
                    srcVar += srcOffset;
                    dst += dstOffset;
                }
            }
        }