How to adjust Brightness and Contrast of an image using a slider?

Question

I have an image and i want to adjust its brightness and contrast through a slider in xaml. I don\'t know where to start.Any help would be appreciated. I am trying to impleme

Answer 1

Btw, correct function for increasing brightness of premultiplied images is

    public static WriteableBitmap ChangeBrightness(WriteableBitmap source, int increment)
    {
        var dest = new WriteableBitmap(source.PixelWidth, source.PixelHeight);

        byte[] color = new byte[4];

        using (var srcBuffer = source.PixelBuffer.AsStream())
        using (var dstBuffer = dest.PixelBuffer.AsStream())
        {
            while (srcBuffer.Read(color, 0, 4) > 0)
            {
                for (int i = 0; i < 3; i++)
                {
                    var value = (float)color[i];
                    var alpha = color[3] / (float)255;
                    value /= alpha;
                    value += increment;
                    value *= alpha;

                    if (value > 255)
                    {
                        value = 255;
                    }

                    color[i] = (byte)value;
                }

                dstBuffer.Write(color, 0, 4);
            }
        }

        return dest;
    }