Check my result , please?

roslaunch rtabmap_ros rgbd_mapping.launch rgb_topic:=/stereo_camera/left/image_rect_color depth_registered_topic:=/stereo_camera/depth camera_info_topic:=/stereo_camera/left/camera_info frame_id:=base_link rtabmap_args:="--delete_db_on_start" estimation:=1 compressed:=true

Use 2 digital camera for stereo camera

My_stereo_camera.launch

<launch>
<group ns="/stereo_camera" >  
        <node name="left" pkg="usb_cam" type="usb_cam_node">
        <param name="video_device" value="/dev/video1" />
        <param name="image_width" value="640" />
        <param name="image_height" value="480" />
        <param name="camera_info_url" type="string" value="file:///home/greenout/catkin_ws/left.yaml" />
        <param name="framerate" value="60" />
        <param name="camera_frame_id" value="left_camera" />
    </node>
 <node name="right" pkg="usb_cam" type="usb_cam_node">
        <param name="video_device" value="/dev/video0" />
        <param name="image_width" value="640" />
        <param name="image_height" value="480" /> 
        <param name="camera_info_url" type="string" value="file:///home/greenout/catkin_ws/right.yaml" />
        <param name="framerate" value="60" />
        <param name="camera_frame_id" value="right_camera" />
    </node>
</group>
  <!-- Rotate the camera frame. -->
  <arg name="pi/2" value="1.5707963267948966" />
  <arg name="optical_rotate" value="0 0 0 -$(arg pi/2) 0 -$(arg pi/2)" />
  <node pkg="tf" type="static_transform_publisher" name="camera_base_link"

        args="0 0 0 0 0 0 left_camera right_camera 100" />  
  <node pkg="tf" type="static_transform_publisher" name="camera_base_link2"
        args="0 0 0 0 0 0 stereo_camera left_camera 100" />  
  <node pkg="tf" type="static_transform_publisher" name="camera_base_link3"
        args="$(arg optical_rotate) base_link stereo_camera 100" />

</launch>

stereo_image_proc for image rectification and disparity computation

<launch>
  <!-- Run the ROS package stereo_image_proc for image rectification and disparity computation -->
<group ns="/stereo_camera" >
    <node   pkg="stereo_image_proc" type="stereo_image_proc" name="stereo_image_proc" required="true" output = "screen">
                    <param name="approximate_sync"           value="true"/>
    </node>
    <node pkg="nodelet" type="nodelet" name="disparity2depth" args="standalone rtabmap_ros/disparity_to_depth"/>
</group>
</launch>

rgbd_mapping.launch

<launch>
  <!-- Your RGB-D sensor should be already started with "depth_registration:=true".
        Examples:
           $ roslaunch freenect_launch freenect.launch depth_registration:=true 
           $ roslaunch openni2_launch openni2.launch depth_registration:=true -->

  <!-- Choose visualization -->
  <arg name="rviz"                    default="true" />
  <arg name="rtabmapviz"              default="false" /> 

  <!-- Corresponding config files -->
  <arg name="rtabmapviz_cfg"          default="-d $(find rtabmap_ros)/launch/config/rgbd_gui.ini" />
  <arg name="rviz_cfg"                default="-d $(find rtabmap_ros)/launch/config/rgbd.rviz" />

  <arg name="frame_id"                default="camera_link"/>   <!-- Fixed frame id, you may set "base_link" or "base_footprint" if they are published -->
  <arg name="time_threshold"          default="0"/>             <!-- (ms) If not 0 ms, memory management is used to keep processing time on this fixed limit. -->
  <arg name="optimize_from_last_node" default="false"/>         <!-- Optimize the map from the last node. Should be true on multi-session mapping and when time threshold is set -->
  <arg name="database_path"           default="~/.ros/rtabmap.db"/>
  <arg name="rtabmap_args"            default=""/>              <!-- delete_db_on_start, udebug -->
  <arg name="launch_prefix"           default=""/>              <!-- for debugging purpose, it fills launch-prefix tag of the nodes -->

  <arg name="rgb_topic"               default="/camera/rgb/image_rect_color" />
  <arg name="depth_registered_topic"  default="/camera/depth_registered/image_raw" />
  <arg name="camera_info_topic"       default="/camera/rgb/camera_info" />
  <arg name="compressed"              default="false"/>
  <arg name="convert_depth_to_mm"     default="true"/>

  <arg name="subscribe_scan"          default="false"/>         <!-- Assuming 2D scan if set, rtabmap will do 3DoF mapping instead of 6DoF -->
  <arg name="scan_topic"              default="/scan"/>

  <arg name="visual_odometry"         default="true"/>          <!-- Generate visual odometry -->
  <arg name="odom_topic"              default="/odom"/>         <!-- Odometry topic used if visual_odometry is false -->

  <arg name="namespace"               default="rtabmap"/>
  <arg name="wait_for_transform"      default="0.1"/>

  <!-- Odometry parameters: -->
  <arg ...