Opencv 10 brightness contrast adjustment

The built-in program to adjust the progress bar will produce a negative width or height , Change the code to rect It can run normally , Examples are as follows ：

 rect.Top = histogramImage.Rows;
                        rect.Left = j * binW;
                        rect.Width = binW;
                        rect.Height = (int)(scaledHistogram.Get<float>(j));
                        histogramImage.Rectangle(
                           rect,
                           color,
                           -1);

Program main function and running logic analysis

The values of brightness and contrast are 0-200 Before ,

After adjustment 100 by 0 Point set positive and negative , Calculate the parameters according to the positive and negative conditions , The code is as follows ：

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;
            }

And then call ConvertTo Function to achieve transformation and display work .

src.ConvertTo(modifiedSrc, MatType.CV_8UC3, alpha, beta);

It should be noted that , The program should be able to output histogram related parameters , After running, there is indeed a histogram window , But the window content is empty , Because there is no relative how to apply , Don't fix this bug.