转换简单的 JavaScript 代码

我一直在尝试转换这个从图像中获取主色的 JavaScript 代码，到目前为止没有成功。我在colorCount和color变量中出现错误。我不知道用于这些变量的合适和等效数据类型。这是我的代码：

public string dominantColor(Bitmap img)
{
       int[] colorCount = new int[0];
       int maxCount = 0;
       string dominantColor = "";
       // data is an array of a series of 4 one-byte values representing the rgba values of each pixel
       Bitmap Bmp = new Bitmap(img);
       BitmapData BmpData = Bmp.LockBits(new Rectangle(0, 0, Bmp.Width, Bmp.Height), ImageLockMode.ReadOnly, Bmp.PixelFormat);
       byte[] data = new byte[BmpData.Stride * Bmp.Height];

       for (int i = 0; i < data.Length; i += 4) 
       {
            // ignore transparent pixels
            if (data[i+3] == 0)
                continue;
            string color = data[i] + "." + data[i+1] + "," + data[i+2];
            // ignore white
            if (color == "255,255,255")
               continue;
            if (colorCount[color] != 0)
               colorCount[color] = colorCount[color] + 1;
            else
               colorCount[color] = 0;
            // keep track of the color that appears the most times
            if (colorCount[color] > maxCount)
            {
                 maxCount = colorCount[color];
                 dominantColor = color.ToString;
            }
       }
       string rgb = dominantColor.Split(",");
       return rgb;   
}

static Color dominantColor(Bitmap img)
{
    Hashtable colorCount = new Hashtable();
    int maxCount = 0;
    Color dominantColor = Color.White;
    for (int i = 0; i < img.Width; i++)
    {
        for (int j = 0; j < img.Height; j++)
        {
            var color = img.GetPixel(i, j);
            if (color.A == 0)
                continue;
            // ignore white
            if (color.Equals(Color.White))
                continue;
            if (colorCount[color] != null)
                colorCount[color] = (int)colorCount[color] + 1;
            else
                colorCount.Add(color, 0);
            // keep track of the color that appears the most times
            if ((int)colorCount[color] > maxCount)
            {
                maxCount = (int)colorCount[color];
                dominantColor = color;
            }
        }
    }
    return dominantColor;
}