@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    Bitmap bitmap = ((BitmapDrawable)this.getDrawable()).getBitmap();

    final int w = bitmap.getWidth();
    final int h = bitmap.getHeight();
    int pixel;
    int redValue;
    int blueValue;
    int greenValue;

    for (int x = 0; x < w; x++) {
        for (int y = 0; y < h; y++) {
            pixel = bitmap.getPixel(x, y);
            redValue = Color.red(pixel);
            blueValue = Color.blue(pixel);
            greenValue = Color.green(pixel);
            if (redValue == 255 && greenValue == 254 && blueValue == 0){
                Paint paint = new Paint();
                paint.setColor(Color.BLACK);
                paint.setTextSize(35);
                canvas.drawText("Some Text", x, y, paint);
            }
        }
    }
}