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2016-06-02 09:13:16 -0500 asked a question Corrupt JPEG data when extracting a bag file

When I try to extract a bag file to jpg images, sometimes, I get this error message:

Corrupt JPEG data: xxxx extraneous bytes before marker 0xxx

I am using image_view package to do so: here is a snippet of the launch file:

  <node name="extract4" pkg="image_view" type="extract_images" respawn="false" output="screen" cwd="node">
    <remap from="image" to="/con$(arg cam4)/image_raw"/>
    <param name="image_transport" value="compressed"/>
    <param name="sec_per_frame" value="0.1"/>
    <param name="filename_format" value="/home/con$(arg cam4)/frame%04i.jpg"/>

Does this mean that the bag file has some corrupted data or something wrong with the way I am extracting the images ?

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2016-05-26 14:37:31 -0500 answered a question cannot extract images from bag file

It turns out that my images are compressed images and I just had to add this line to the launch file:

<param name="image_transport" value="compressed"/>
2016-05-26 13:09:43 -0500 asked a question cannot extract images from bag file

i am using Ubuntu 14.04 and Ros Indigo. I am trying to extract images from a bag file, I am using this launch file:

  <node pkg="rosbag" type="play" name="rosbag" args="-d 30 $(find image_view)/test.bag"/>
  <node name="extract" pkg="image_view" type="extract_images" respawn="false" output="screen" cwd="ROS_HOME">
    <remap from="image" to="/ci109/image_raw"/>
    <param name="filename_format" value="~/test/frame%06i.jpg"/>

I am away of this question wiki and this question. It seems like it is running fine but I do not see anything like

[ INFO] [1303939096.111425424]: Saved image frame0000.jpg

And I don't see any image in the .ros folder or the ~/test folder that I created to test. Here is my output:


 * /extract/filename_format: /home/charis/test...
 * /rosdistro: indigo
 * /rosversion: 1.11.19

    extract (image_view/extract_images)
    rosbag (rosbag/play)


core service [/rosout] found
process[rosbag-1]: started with pid [15728]
process[extract-2]: started with pid [15729]
[ INFO] [1464279324.985270766]: Initialized sec per frame to 0.100000
[rosbag-1] process has finished cleanly

I did make sure that the bag file is in place. Basically, it seems that the console stays put for a while at

[ INFO] [1464288031.072128668]: Initialized sec per frame to 0.100000

then it says process has finished cleanly !

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2016-03-05 19:20:34 -0500 asked a question seg fault using pcl::PCDReader with c++11

I have a code which was running fine until I switched to C++11. I have been debugging this error for a long time, until I narrow it down to this line pcl::PCDReader reader;

int main (int argc, char** argv)
      pcl::PCDReader reader;
      return (0);

I tried also this method to read point cloud file and I got the same problem,

if (pcl::io::loadPCDFile<pcl::PointXYZ> (argv[1], *cloud_filtered) == -1) //* load the file
    PCL_ERROR ("Couldn't read file test_pcd.pcd \n");
    return (-1);

I think something is wrong with IO process... I am using these headers:

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <pcl/ModelCoefficients.h>
#include <pcl/io/pcd_io.h>
#include <pcl/point_types.h>
#include <pcl/sample_consensus/method_types.h>
#include <pcl/sample_consensus/model_types.h>
#include <pcl/segmentation/sac_segmentation.h>
#include <pcl/segmentation/plane_coefficient_comparator.h>
#include <pcl/filters/voxel_grid.h>
#include <pcl/filters/extract_indices.h>
#include <pcl/kdtree/kdtree.h>
#include <pcl/segmentation/sac_segmentation.h>
#include <pcl/segmentation/extract_clusters.h>
#include <pcl/visualization/cloud_viewer.h>

I am using PCL 1.7 on Ubuntu 14.04

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2015-11-09 21:56:52 -0500 asked a question how to install bullet on Indigo in Ubuntu

I have been trying to build this project, it has tf2_bullet which is part of geometry_experimental in it and depends on bullet, So I have been getting this error message whenever I try to do catkin_make

-- checking for module 'bullet'
--   package 'bullet' not found

I have done some research and I could not find bullet package. I installed bullet3 from bullet github but that did not solve the problem Any help would be appreciated...

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2015-08-09 19:18:40 -0500 asked a question How to use kinect to update occupancy grid

I have a robot which already using Lidar to for SLAM and it seems to function well. Now, I would like to add Kinect to help improving final map. Kinect can get x,y,z of these obstacles with respect to the camera frame. Now, I want to use x,y to update the occupancy grid along with Lidar already doing. How can this be done? Any hint would be appreciated. I am using ROS Indigo with Ubuntu x86-64.

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2015-07-30 19:05:14 -0500 marked best answer processing kinect depth frame is very slow

I am processing depth frame from Kinect try to find the ground floor, I am using simple method of computing for each pixel whether they belong to the equation of ground surface or not, I already computed a,b,c,d parameters of the equation of the ground, and I would like to process each pixel to be able to accept it as a ground pixel or now. Here is a snippet of my code for processing each frame:

for i in xrange(rows):
      for j in xrange(cols):
          x0 = frame[i, j]*math.cos((j-midx)*ax)*math.sin((i-midy)*ay)
          y0 = frame[i, j]*math.sin((j-midx)*ax)*math.sin((i-midy)*ay)
          z0 = frame[i, j]*math.cos((i-midy)*ay)    
          if abs(self.a*x0+self.b*y0+self.c*z0-self.d) < 0.0002:
              frame[i,j] = 10

for some reason each frame take more than 10 seconds to finish. This seems extremely slow. I am not sure why. Any help would be appreciate it.
EDIT: Here are my computer info:

Processor: Intel® Core™2 Duo CPU T6400 @ 2.00GHz × 2

Ram: 3GB