如何获得图像的平均颜色

Bitmap bitmap = someFunctionReturningABitmap();long redBucket = 0;long greenBucket = 0;long blueBucket = 0;long pixelCount = 0;for (int y = 0; y < bitmap.getHeight(); y++){    for (int x = 0; x < bitmap.getWidth(); x++)    {        Color c = bitmap.getPixel(x, y);        pixelCount++;        redBucket += Color.red(c);        greenBucket += Color.green(c);        blueBucket += Color.blue(c);        // does alpha matter?    }}Color averageColor = Color.rgb(redBucket / pixelCount,          greenBucket / pixelCount,          blueBucket / pixelCount);