Can I Use Message filter for subscribing RGB and Depth images simultaneously?

hello All,
I’m facing a serious problem related to topic subscribing in ROS.

I want to subscribe two topics simultaneously using ApproximateTime Policy or ExactTime Policy.

My implementtation is as given below.

ros::init(argc, argv, “vision_node”);

ros::NodeHandle nh;

message_filters::Subscriber<Image> RGB_sub(nh, "/camera/rgb/image_color", 1);
message_filters::Subscriber<sensor_msgs::PointCloud2> PointCloud_sub(nh, "/camera/depth/points", 1);

typedef sync_policies::ApproximateTime<Image, sensor_msgs::PointCloud2> MySyncPolicy;

// ApproximateTime takes a queue size as its constructor argument, hence MySyncPolicy(10)
Synchronizer<MySyncPolicy> sync(MySyncPolicy(10), RGB_sub, PointCloud_sub);
sync.registerCallback(boost::bind(&callback, _1, _2));

and the callback is like this…
void callback(const ImageConstPtr& image_rgb, const sensor_msgs::PointCloud2::ConstPtr& pCloud)

But this is not working.
what can be done to solve this problem? I’m using ROS Kinectic and Astra Pro.