首先看一下教程：

http://wiki.ros.org/openni_launch/Tutorials/BagRecordingPlayback

知道了rosbag如何進行使用記錄深度數據

但是按照以上教程記錄下來的bag file還是很大

於是看了別人寫的launch file

摘抄自spencer_people_tracking

<!-- Launch file for playing bagfiles recorded with the SPENCER robot platform -->
<launch>
  <!-- CONFIGURABLE ARGUMENTS -->
  <arg name="files" default=""/>
  <arg name="folder" default=""/>
  
  <arg name="urdf" default="false"/>
  <arg name="remap_tf" default="true" if="$(arg urdf)"/>
  <arg name="remap_tf" default="false" unless="$(arg urdf)"/>
  
  <arg name="depth" default="true"/>
  <arg name="no_point_clouds" default="false" />
  <arg name="front_rgbd" default="true"/>
  <arg name="rear_rgbd" default="true"/>
  <arg name="laser" default="true"/>
  <arg name="uncompress_rgbd" default="true"/>
  <arg name="tracked_persons" default="true"/>
  <arg name="velodyne" default="false"/>

  <!-- Playback options -->
  <arg name="rqt" default="false"/>
  <arg name="pause" default="true"/>
  <arg name="initial_wait_time" default="0.0" if="$(arg pause)"/>
  <arg name="initial_wait_time" default="45.0" unless="$(arg pause)"/>
  <arg name="loop" default="false"/>
  <arg name="start" default="0.0"/> <!-- seconds into the bagfile at which to start playing -->
  <arg name="duration" default="99999999.9"/> <!-- number of seconds to play -->
  <arg name="rate" default="1.0"/> <!-- playback speed -->
  <arg name="required" default="true" />

  <!-- Visualization options -->
  <arg name="visualization" default="true" /> <!-- whether to run RViz with provided config, or not -->
  <arg name="panoramas" default="false"/>
  <arg name="relay_rgbd_for_visualization" default="true"/>
  <arg name="rviz_config_file" default="$(find spencer_bagfile_tools)/launch/components/visualization_robot.rviz"/> <!-- configuration file for RViz to use, if visualization is enabled -->

  <arg name="rosbag_play_args" default="--clock --queue=5 --delay=0 --start=$(arg start) --duration=$(arg duration) --rate=$(arg rate)" /> <!-- extra arguments used to play back the bagfile -->

  <!-- Important: Use simulated time published on /clock topic, otherwise TF will be broken -->
  <param name="/use_sim_time" value="true"/>


  <!-- BAG FILE PLAYBACK -->
  <group>
    <remap from="/tf" to="/spencer/sensors/tf_in_bagfile" if="$(arg remap_tf)"/>
    <remap from="/spencer/sensors/clock" to="/clock"/>

    <remap from="/spencer/perception/tracked_persons" to="/spencer/perception/tracked_persons_in_bagfile" unless="$(arg tracked_persons)"/>
    <remap from="/spencer/perception/detected_persons" to="/spencer/perception/detected_persons_in_bagfile" unless="$(arg tracked_persons)"/>

    <!-- Uncompress RGB-D images -->
    <remap if="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_front_top/depth/image_raw/compressedDepth" to="/spencer/sensors/rgbd_front_top/depth_recorded/image_raw/compressedDepth"/>
    <remap if="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_front_top/rgb/image_raw/compressed"    to="/spencer/sensors/rgbd_front_top/rgb_recorded/image_color/compressed"/>

    <remap if="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_front_bottom/depth/image_raw/compressedDepth" to="/spencer/sensors/rgbd_front_bottom/depth_recorded/image_raw/compressedDepth"/>
    <remap if="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_front_bottom/rgb/image_raw/compressed"    to="/spencer/sensors/rgbd_front_bottom/rgb_recorded/image_color/compressed"/>

    <remap if="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_rear_top/depth/image_raw/compressedDepth" to="/spencer/sensors/rgbd_rear_top/depth_recorded/image_raw/compressedDepth"/>
    <remap if="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_rear_top/rgb/image_raw/compressed"    to="/spencer/sensors/rgbd_rear_top/rgb_recorded/image_color/compressed"/>

    <remap if="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_rear_bottom/depth/image_raw/compressedDepth" to="/spencer/sensors/rgbd_rear_bottom/depth_recorded/image_raw/compressedDepth"/>
    <remap if="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_rear_bottom/rgb/image_raw/compressed"    to="/spencer/sensors/rgbd_rear_bottom/rgb_recorded/image_color/compressed"/>


    <!-- Hack if uncompressed depth/image_rect was recorded instead of depth/image_raw as recommended at http://wiki.ros.org/openni_launch/Tutorials/BagRecordingPlayback -->
    <remap unless="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_front_top/depth/image_rect" to="/spencer/sensors/rgbd_front_top/depth/image_raw"/>
    <remap unless="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_front_bottom/depth/image_rect" to="/spencer/sensors/rgbd_front_bottom/depth/image_raw"/>

    <remap unless="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_rear_top/depth/image_rect"  to="/spencer/sensors/rgbd_rear_top/depth/image_raw"/>
    <remap unless="$(arg uncompress_rgbd)" from="/spencer/sensors/rgbd_rear_bottom/depth/image_rect"  to="/spencer/sensors/rgbd_rear_bottom/depth/image_raw"/>


    <!-- This script launches either rosbag play or rqt_bag, and searches for all relevant bag files for the active sensor modalities in the given folder -->
    <node name="playback_wrapper" pkg="spencer_bagfile_tools" type="play.py" output="screen" required="$(arg required)" ns="/spencer/sensors" clear_params="true"> <!-- sub-namespace only applied for relative topic names in bagfile -->
      <!-- Either give a list of files... -->
      <param name="files" value="$(arg files)"/>

      <!-- Or an entire folder containing bagfiles prefixed with laser_, front_rgbd_, etc. -->
      <param name="folder" value="$(arg folder)"/>
      <param name="laser" value="$(arg laser)"/>
      <param name="front_rgbd" value="$(arg front_rgbd)"/>
      <param name="rear_rgbd" value="$(arg rear_rgbd)"/>

      <param name="rqt" value="$(arg rqt)"/>
      <param name="pause" value="$(arg pause)"/>
      <param name="loop" value="$(arg loop)"/>
      <param name="rosbag_play_args" value="$(arg rosbag_play_args)"/>
      <param name="initial_wait_time" value="$(arg initial_wait_time)"/>
    </node>
  </group>


  <!-- TF EXCLUSIONS -->
  <group if="$(arg remap_tf)">
    <remap from="tf_old" to="/spencer/sensors/tf_in_bagfile"/>
    <node name="tf_filter" pkg="spencer_bagfile_tools" type="tf_filter.py" args="_exclude:=‘[]‘"/>
  </group>


  <!-- RGB-D PROCESSING -->
  <group if="$(arg depth)">
    <!-- Uncompress RGB-D -->
    <group if="$(arg uncompress_rgbd)">
      <include file="$(find spencer_bagfile_tools)/launch/components/uncompress_rgbd.launch">
        <arg name="sensor_name" value="rgbd_front_top"/>
      </include>
      <include file="$(find spencer_bagfile_tools)/launch/components/uncompress_rgbd.launch">
        <arg name="sensor_name" value="rgbd_front_bottom"/>
      </include>
      <include file="$(find spencer_bagfile_tools)/launch/components/uncompress_rgbd.launch">
        <arg name="sensor_name" value="rgbd_rear_top"/>
      </include>
      <include file="$(find spencer_bagfile_tools)/launch/components/uncompress_rgbd.launch">
        <arg name="sensor_name" value="rgbd_rear_bottom"/>
      </include>
    </group>

    <!-- Generate point clouds -->
    <group unless="$(arg no_point_clouds)" ns="/spencer/sensors/">
      <!-- Front sensors -->
      <group if="$(arg front_rgbd)">
        <include file="$(find spencer_bagfile_tools)/launch/components/generate_pointcloud.launch">
          <arg name="sensor_name" value="rgbd_front_top"/>
        </include>
        <include file="$(find spencer_bagfile_tools)/launch/components/generate_pointcloud.launch">
          <arg name="sensor_name" value="rgbd_front_bottom"/>
        </include>
      </group>

      <!-- Rear sensors -->
      <group if="$(arg rear_rgbd)">
        <include file="$(find spencer_bagfile_tools)/launch/components/generate_pointcloud.launch">
          <arg name="sensor_name" value="rgbd_rear_top"/>
        </include>
        <include file="$(find spencer_bagfile_tools)/launch/components/generate_pointcloud.launch">
          <arg name="sensor_name" value="rgbd_rear_bottom"/>
        </include>
      </group>
    </group>
  </group>


  <!-- Relay original RGB-D images to throttled visualization topics (for playback, we don‘t need compression and throttling) -->
  <group if="$(arg relay_rgbd_for_visualization)" ns="relay_rgbd_for_visualization">
    <node pkg="nodelet" type="nodelet" name="manager" args="manager" output="screen"/>

    <include file="$(find spencer_bagfile_tools)/launch/components/relay_rgbd_for_visualization.launch">
      <arg name="camera" value="rgbd_front_top"/>
    </include>

    <include file="$(find spencer_bagfile_tools)/launch/components/relay_rgbd_for_visualization.launch">
      <arg name="camera" value="rgbd_front_bottom"/>
    </include>

    <include file="$(find spencer_bagfile_tools)/launch/components/relay_rgbd_for_visualization.launch">
      <arg name="camera" value="rgbd_rear_top"/>
    </include>

      <include file="$(find spencer_bagfile_tools)/launch/components/relay_rgbd_for_visualization.launch">
      <arg name="camera" value="rgbd_rear_bottom"/>
    </include>
  </group>


  <!-- Create RGB and depth panoramas for visualization -->
  <group if="$(arg panoramas)" ns="/spencer/sensors">
    <node if="$(arg front_rgbd)" name="panorama_rgb_front" pkg="spencer_bagfile_tools" type="panorama_builder" args="_topics:=‘/spencer/sensors/rgbd_front_top/rgb /spencer/sensors/rgbd_front_bottom/rgb‘ _inplane_rotations:=‘0.0 180.0‘ _vertical:=true _output_topic:=‘/spencer/sensors/rgbd_front_panorama/rgb‘"/>

    <node if="$(arg rear_rgbd)" name="panorama_rgb_rear" pkg="spencer_bagfile_tools" type="panorama_builder" args="_topics:=‘/spencer/sensors/rgbd_rear_top/rgb /spencer/sensors/rgbd_rear_bottom/rgb‘ _inplane_rotations:=‘0.0 180.0‘ _vertical:=true _output_topic:=‘/spencer/sensors/rgbd_rear_panorama/rgb‘"/>

    <group if="$(arg depth)">
      <node if="$(arg front_rgbd)" name="panorama_depth_front" pkg="spencer_bagfile_tools" type="panorama_builder" args="_topics:=‘/spencer/sensors/rgbd_front_top/depth /spencer/sensors/rgbd_front_bottom/depth‘ _inplane_rotations:=‘0.0 180.0‘ _vertical:=true _output_topic:=‘/spencer/sensors/rgbd_front_panorama/depth‘"/>

      <node if="$(arg rear_rgbd)" name="panorama_depth_rear" pkg="spencer_bagfile_tools" type="panorama_builder" args="_topics:=‘/spencer/sensors/rgbd_rear_top/depth /spencer/sensors/rgbd_rear_bottom/depth‘ _inplane_rotations:=‘0.0 180.0‘ _vertical:=true _output_topic:=‘/spencer/sensors/rgbd_rear_panorama/depth‘"/>
    </group>
  </group>


  <!-- VELODYNE POINT CLOUD GENERATION -->
  <group if="$(arg velodyne)">
    <include file="$(find velodyne_pointcloud)/launch/VLP16_points.launch"/>
  </group>


  <!-- ROBOT URDF -->
  <group if="$(arg urdf)">
    <include file="$(find spencer_description)/launch/publish.launch"/>
  </group>

  <!-- VISUALIZATION -->
  <node name="rviz" pkg="rviz" type="rviz" args="-d $(arg rviz_config_file)" required="false" if="$(arg visualization)"/>

</launch>

可以看到解壓縮，rosbag info 以下別人的bag file

topics:

/spencer/sensors/rgbd_front_top/depth/camera_info 720 msgs : sensor_msgs/CameraInfo
/spencer/sensors/rgbd_front_top/depth/image_raw/compressedDepth 720 msgs : sensor_msgs/CompressedImage
/spencer/sensors/rgbd_front_top/rgb/camera_info 691 msgs : sensor_msgs/CameraInfo
/spencer/sensors/rgbd_front_top/rgb/image_raw/compressed 691 msgs : sensor_msgs/CompressedImage

發現記錄的都是壓縮格式的深度圖，和彩色圖

於是需要解壓縮

別人的uncompress_rgbd.launch

<launch>
    <arg name="sensor_name"/>

    <group ns="/spencer/sensors/$(arg sensor_name)">
　　　　　<!--註意這裏是base topic就是說這個base topic下的所有topic都會被變換-->
        <node name="republish_rgb"   pkg="image_transport" type="republish" args="compressed in:=rgb_recorded/image_color raw out:=rgb/image_raw"/>
        <node name="republish_depth" pkg="image_transport" type="republish" args="compressedDepth in:=depth_recorded/image_raw raw out:=depth/image_raw"/>
    </group>

</launch>

發現用到了image_transport

於是去看

http://wiki.ros.org/image_transport

和

http://wiki.ros.org/image_transport_plugins

rosbag使用--記錄深度相機數據