ar_track_alvar image topic to point cloud

edit

Hi there! This is my first time using AR Tags in ROS. I already had my camera with /image_raw and /camera_info topics published. However, when I ran "roslaunch ar_track_alvar pr2_indiv.launch"

there was an error saying: "Could not process inbound connection: topic types do not match: [sensor_msgs/PointCloud2] vs [sensor_msgs/Image]"

I believe my sensor_msgs/Image topic already correct, since I can visualize them in rviz and in image_view. Is this a bug? since in the instructions it is clearly stated that Image topic is used...

Thanks for your help!