Husarnet Tutorial , smartphone view orientation

Software
1

Hi Husarion Team,

Reference:
https://husarion.com/tutorials/husarnet/following-object-using-your-smartphone/

My 3 nodes are working fine.
My robot reacts to the object-position on the viewing panel of FIND-OBJECT shell

The view of the surrounding on the FIND-OBJECT panel, while the smartphone is in the portrait-stand, is 90 degree rotated to the right.

Question is, how can I correct this mismatch?

Thanks and regards,
Fred

2

Hello Fred,

I think you could use image_rotate package to position your camera view correctly.
You can find it here:
http://wiki.ros.org/image_rotate

Regards,
Łukasz

3

Hello Lukasz,

Thanks the link you have provided me.

My problem is related to the “following-object-using_your_smartphone” sample

I have tried to use it, but I am not able to achieve something with the view on the Find-Object panel.

How do I have to link this ‘image_rotate’ -method to the image coming from the camera of the smartphone,
before it is grabbed and used by the “object_follower” program and executed by “follower_main”
Can you help me on this?
Thanks and regards,
Fred

4

Hello Fred,

I prepared a launch file that uses image_rotate node, this is a complete example, provided that you have phone and laptop connected in husarnet.

<launch>
    <node pkg="image_rotate" type="image_rotate" name="image_rotater">
        <remap from="image" to="/localimg"/>
        <param name="use_camera_info" value="true"/>
        <param name="target_x" value="-1"/>
    </node>
    <node pkg="find_object_2d" type="find_object_2d" name="find_object_2d" output="screen">
        <remap from="image" to="/rotated/image"/>
        <param name="gui" value="true"/>
    </node>
    <node pkg="tf" type="static_transform_publisher" name="tf4" args="0 0 0 0 0 0 base_link front 100" />
    <node pkg="image_transport" type="republish" name="republish" output="screen" args="compressed in:=/myPhone/camera0/image out:=/localimg">
    </node>
</launch>

Moreover image rotate needs camera info to work properly, it can be published with a python script:

#!/usr/bin/env python
import rospy
from sensor_msgs.msg import CameraInfo
from sensor_msgs.msg import Image
import std_msgs.msg

camera_info_msg = 0

def callback(data):
    global camera_info_msg
    camera_info_msg.header=data.header
    camera_info_msg.header.frame_id="front"
    publisher.publish(camera_info_msg)

if __name__ == "__main__":
    camera_info_msg = CameraInfo()
    camera_info_msg.width = 640
    camera_info_msg.height = 480
    camera_info_msg.K = [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
    camera_info_msg.D = []
    camera_info_msg.R = [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
    camera_info_msg.P = [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
    camera_info_msg.distortion_model = ''
    # Initialize publisher node
    rospy.init_node("camera_info_publisher", anonymous=True)
    publisher = rospy.Publisher("camera_info", CameraInfo, queue_size=10)

    rospy.Subscriber("localimg", Image, callback)
    rospy.spin()

Regards,
Łukasz

5

Hello Lukasz,

Your program does its jobs! Excellent.

I have only changed the line

into to get the correct orientation.

I am happy with the view now and it does not look silly anymore!

Thank you very much for the great help.
Best regards,
Fred

6

lines are not showing up in my previous message

I have changed the value of the parameter “target_x” from -1 into 1