OpenCVSharp #10

private static void updateBrightnessContrast(Mat src, Mat modifiedSrc, int brightness, int contrast)
{    brightness = brightness - 100;    contrast = contrast - 100;    double alpha, beta;    if (contrast > 0)    {        double delta = 127f * contrast / 100f;        alpha = 255f / (255f - delta * 2);        beta = alpha * (brightness - delta);    }    else    {        double delta = -128f * contrast / 100;        alpha = (256f - delta * 2) / 255f;        beta = alpha * brightness + delta;    }    src.ConvertTo(modifiedSrc, MatType.CV_8UC3, alpha, beta);
}

using (var src = new Mat(@"..\..\Images\Penguin.Png", LoadMode.AnyDepth | LoadMode.AnyColor))
{    using (var sourceWindow = new Window("Source", image: src,           flags: WindowMode.AutoSize | WindowMode.FreeRatio))    {        using (var histogramWindow = new Window("Histogram",               flags: WindowMode.AutoSize | WindowMode.FreeRatio))        {            var brightness = 100;            var contrast = 100;            var brightnessTrackbar = sourceWindow.CreateTrackbar(                    name: "Brightness", value: brightness, max: 200,                    callback: pos =>                    {                        brightness = pos;                        updateImageCalculateHistogram(sourceWindow, histogramWindow, src, brightness, contrast);                    });            var contrastTrackbar = sourceWindow.CreateTrackbar(                name: "Contrast", value: contrast, max: 200,                callback: pos =>                {                    contrast = pos;                    updateImageCalculateHistogram(sourceWindow, histogramWindow, src, brightness, contrast);                });            brightnessTrackbar.Callback.DynamicInvoke(brightness);            contrastTrackbar.Callback.DynamicInvoke(contrast);            Cv2.WaitKey();        }    }
}

private static void calculateHistogram1(Window histogramWindow, Mat src, Mat modifiedSrc)
{    const int histogramSize = 64;    int[] dimensions = { histogramSize }; // Histogram size for each dimension    Rangef[] ranges = { new Rangef(0, histogramSize) }; // min/max    using (var histogram = new Mat())    {        Cv2.CalcHist(            images: new[] { modifiedSrc },            channels: new[] { 0 },            mask: null,            hist: histogram,            dims: 1,            histSize: dimensions,            ranges: ranges);        using (var histogramImage = (Mat)(Mat.Ones(rows: src.Rows, cols: src.Cols, type: MatType.CV_8U) * 255))        {            // Scales and draws histogram            Cv2.Normalize(histogram, histogram, 0, histogramImage.Rows, NormType.MinMax);            var binW = Cv.Round((double)histogramImage.Cols / histogramSize);            var color = Scalar.All(100);            for (var i = 0; i < histogramSize; i++)            {                Cv2.Rectangle(histogramImage,                    new Point(i * binW, histogramImage.Rows),                    new Point((i + 1) * binW, histogramImage.Rows - Cv.Round(histogram.Get<float>(i))),                    color,                    -1);            }            histogramWindow.Image = histogramImage;        }    }
}