Accord.Imaging.ImageStatisticsYCbCr.ProcessImage C# (CSharp) Method

        private unsafe void ProcessImage(UnmanagedImage image, byte* mask, int maskLineSize)
        {
            // get image dimension
            int width = image.Width;
            int height = image.Height;

            pixels = pixelsWithoutBlack = 0;

            int[] yhisto = new int[256];
            int[] cbhisto = new int[256];
            int[] crhisto = new int[256];

            int[] yhistoWB = new int[256];
            int[] cbhistoWB = new int[256];
            int[] crhistoWB = new int[256];

            RGB rgb = new RGB();
            YCbCr ycbcr = new YCbCr();

            int pixelSize = (image.PixelFormat == PixelFormat.Format24bppRgb) ? 3 : 4;
            int offset = image.Stride - width * pixelSize;
            int maskOffset = maskLineSize - width;

            // do the job
            byte* p = (byte*)image.ImageData.ToPointer();

            if (mask == null)
            {
                // for each line
                for (int y = 0; y < height; y++)
                {
                    // for each pixel
                    for (int x = 0; x < width; x++, p += pixelSize)
                    {
                        rgb.Red = p[RGB.R];
                        rgb.Green = p[RGB.G];
                        rgb.Blue = p[RGB.B];

                        // convert to YCbCr color space
                        Accord.Imaging.YCbCr.FromRGB(rgb, ycbcr);

                        yhisto[(int)(ycbcr.Y * 255)]++;
                        cbhisto[(int)((ycbcr.Cb + 0.5) * 255)]++;
                        crhisto[(int)((ycbcr.Cr + 0.5) * 255)]++;

                        pixels++;

                        if ((ycbcr.Y != 0.0) || (ycbcr.Cb != 0.0) || (ycbcr.Cr != 0.0))
                        {
                            yhistoWB[(int)(ycbcr.Y * 255)]++;
                            cbhistoWB[(int)((ycbcr.Cb + 0.5) * 255)]++;
                            crhistoWB[(int)((ycbcr.Cr + 0.5) * 255)]++;

                            pixelsWithoutBlack++;
                        }
                    }
                    p += offset;
                }
            }
            else
            {
                // for each line
                for (int y = 0; y < height; y++)
                {
                    // for each pixel
                    for (int x = 0; x < width; x++, p += pixelSize, mask++)
                    {
                        if (*mask == 0)
                            continue;

                        rgb.Red = p[RGB.R];
                        rgb.Green = p[RGB.G];
                        rgb.Blue = p[RGB.B];

                        // convert to YCbCr color space
                        Accord.Imaging.YCbCr.FromRGB(rgb, ycbcr);

                        yhisto[(int)(ycbcr.Y * 255)]++;
                        cbhisto[(int)((ycbcr.Cb + 0.5) * 255)]++;
                        crhisto[(int)((ycbcr.Cr + 0.5) * 255)]++;

                        pixels++;

                        if ((ycbcr.Y != 0.0) || (ycbcr.Cb != 0.0) || (ycbcr.Cr != 0.0))
                        {
                            yhistoWB[(int)(ycbcr.Y * 255)]++;
                            cbhistoWB[(int)((ycbcr.Cb + 0.5) * 255)]++;
                            crhistoWB[(int)((ycbcr.Cr + 0.5) * 255)]++;

                            pixelsWithoutBlack++;
                        }
                    }
                    p += offset;
                    mask += maskOffset;
                }
            }

            // create histograms
            yHistogram = new ContinuousHistogram(yhisto, new Range(0.0f, 1.0f));
            cbHistogram = new ContinuousHistogram(cbhisto, new Range(-0.5f, 0.5f));
            crHistogram = new ContinuousHistogram(crhisto, new Range(-0.5f, 0.5f));

            yHistogramWithoutBlack = new ContinuousHistogram(yhistoWB, new Range(0.0f, 1.0f));
            cbHistogramWithoutBlack = new ContinuousHistogram(cbhistoWB, new Range(-0.5f, 0.5f));
            crHistogramWithoutBlack = new ContinuousHistogram(crhistoWB, new Range(-0.5f, 0.5f));
        }