To view the disparity map alongside the disparity image, use: "rosrun image_view stereo_view stereo:=/camera image:=image_rect_color"
To view the disparity map alongside the disparity image, use: "rosrun image_view stereo_view stereo:=/stereo_camera image:=image_rect _queue_size:=20"
To view the depth_map use: "rosrun image_view image_view image:=/depth_raw"
To adjust the parameters for the disparity map generation in real time use: "rosrun rqt_reconfigure rqt_reconfigure"
There's more information at the following links: