Unable to extract images from *.bag

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Proceeding further, "roslaunch export.launch" gives the error process[rosbag-1]: started with pid [5274] [FATAL] [1394450389.001846739]: Error opening file: play process[extract-2]: started with pid [5286] [ INFO] [1394450389.280192931]: Initialized sec per frame to 0.100000 [rosbag-1] process has died [pid 5274, exit code 1, cmd /opt/ros/hydro/lib/rosbag/play play -d 2 /opt/ros/hydro/share/image_view/first.bag __name:=rosbag __log:=/home/master/.ros/log/d6ea7ee6-a841-11e3-8d46-60eb69709e0d/rosbag-1.log].

This tutorial requires that you have previously recorded a bag file which contains image data you would like to export as jpeg images or video.

Record a rosbag with an image stream and change args of the rosbag node in launch according to where your bag file is placed. Futhermore the remap tag of image_view node has to be set to the image topic you have recorded into your rosbag

my export.launch file "<launch> <node pkg="rosbag" type="rosbag" name="rosbag" args="play -d 2 /home/master/flare.bag"> <node name="extract" pkg="image_view" type="extract_images" respawn="false" output="screen" cwd="node"> <remap from="image" to="/camera/image_raw"> </remap></node> </node></launch>" -- MY "rosbag info first.bag" OUTPUT-------- path: first.bag version: 2.0 duration: 2:10s (130s) start: Feb 03 2014 07:51:42.82 (1391394102.82) end: Feb 03 2014 07:53:53.55 (1391394233.55) size: 47.3 MB messages: 1056 compression: none [61/61 chunks] types: sensor_msgs/CompressedImage [8f7a12909da2c9d3332d540a0977563f] topics: /front_camera/camera/image_rect_color/compressed 1056 msgs : sensor_msgs/CompressedImage

<launch> <node pkg="rosbag" type="rosbag" name="rosbag" args="play -d 2 /home/master/first.bag"> <node name="extract" pkg="image_view" type="extract_images" respawn="false" output="screen" cwd="node"> <remap from="image" to="/front/camera/image_rect_color/compressed"> </remap></node></node></launch>

You can try this one. I am not sure whether image_view can handle compressed images, though. Maybe also try to record image_raw of your camera....