Gray Out an Image in android

In android, Sometimes, we have to gray out image to show it disable or to show it differently.

So I share my code to gray out any ImageView. We just do it by using pixels.

private ImageView instagramIcon;
instagramIcon =(ImageView)rootView.findViewById(R.id.instagram_image);

public static Bitmap grayOutImage(Bitmap src) {
        // constant factors
        final double G_RED = 0.299;
        final double G_GREEN = 0.587;
        final double G_BLUE = 0.114;


    // create output bitmap
    Bitmap bmOut = Bitmap.createBitmap(src.getWidth(), src.getHeight(), src.getConfig());
    // pixel information
    int A, R, G, B;
    int pixel;

    // get image size
    int width = src.getWidth();
    int height = src.getHeight();

    // scan through every single pixel
    for(int x = 0; x < width; ++x) {
        for(int y = 0; y < height; ++y) {
            // get one pixel color
            pixel = src.getPixel(x, y);
            // retrieve color of all channels
            A = Color.alpha(pixel);
            R = Color.red(pixel);
            G = Color.green(pixel);
            B = Color.blue(pixel);
            // take conversion up to one single value
            R = G = B = (int)(G_RED * R + G_GREEN * G + G_BLUE * B);
            // set new pixel color to output bitmap
            bmOut.setPixel(x, y, Color.argb(A, R, G, B));
        }
    }

    // return final image
    return bmOut;
}

and apply this like

instagramIcon.setImageBitmap(grayScaleImage(BitmapFactory.decodeResource(getResources(),R.drawable.instagram_icon)));