Questions tagged [opencv]
OpenCV (Open Source Computer Vision) is a cross-platform library of programming functions for real time computer vision.
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Drone Line Follower
Hello everyone, I am working a project where I want to follow a straight line to clean gutters. I read up on opencv for image processing. This is my thought process:...
mikerosz
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2
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Scan an Auditorium, Count People, and Display Open Seats [closed]
I'm looking for any recommended approaches to be able to digitally process a room full people, like an auditorium or a movie theater and output the following information:
How many people are in the ...
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what is the use of " .format(**config)) "
http://wiki.ros.org/dynamic_reconfigure/Tutorials/SettingUpDynamicReconfigureForANode%28python%29
in this link ^, they have this piece of code (shown below)
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MukulKhanna
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For dynamic reconfiguration, which is the main file?
http://wiki.ros.org/dynamic_reconfigure/Tutorials
In these tutorials, they have shown to create 1) a config file
2) a client file
3) a server file
I want to dynamically reconfigure the HSV values for ...
MukulKhanna
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How can I show a set of 2D coordinates detected by opencv in rviz
I used opencv fast detection to detect the corner in the image. I tried to use visualization_msg/Marker to publish the 2D coordinate of a set of corners to rviz. However, when I add marker topic in ...
siweiguo
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Using image callback and videocallback OpenCV Kinetic
Hi all! First question in the site!
Hope you guys can help me out, I've got a problem by trying to use an image inside a function. In this function I got an example of edge detector from the camera. I ...
DAC31415
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how can i capture an image from camera using opencv c++ code in ROS?
This is my code:
but I don't how to use it in ROS.Please help me step by step.
...
omar1995
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570
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Tracking a ball returning its x,y,z coordinates [closed]
I'm a Mechatronics Student Engineer, and still new with the computer vision field and am now working on a project that needs to Tracks a small ball and need to determine it's (x,y,z).
1st) Kinect was ...
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632
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Mobile robot pose estimation
I want to plot the path of a vehicle via the estimation of egomotion based on essential matrix.
Everything was fine with openCV and the following function.
...
- 125
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Maintaining scale factor for essential matrix
I want to recover the trajectory of a vehicle using a monocular camera via the computation of the essential matrix between t-1 and ...
- 125
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2
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Conversion from 32FC1 to mono8 using cv_bridge
I am trying to use cv_bridge to convert an image from /disp_map/image (32FC1 encoding according to msg->encoding ) to an ...
jeanpolochon
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Are homogeneous coordinates represented by appending image coordinates with a 1 in camera imaging
In camera imaging, there are several terms for point coordinates.
World coordinates: [X, Y, Z] in physical unit
Image coordinates: [u, v] in pixel.
Do these coordinates become homogeneous ...
- 273
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normalized point coordinates in undistortPoints function
In undistortPoints function from OpenCV, the documentations says that
http://docs.opencv.org/2.4/modules/imgproc/doc/geometric_transformations.html#undistortpoints
where undistort() is an ...
- 273
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Which is the best visual fiducial marker (2D barcode)?
Which is the best visual fiducial marker (2D barcode) for detection and robust and accurate pose estimation?
Im not looking for a fiducial marker which can store lot of information. The main goal is ...
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add local opencv to path
I want to compile my ROS node with the opencv which is at /usr/local/ I have tried the following rosanswers
I could compile my code without errors. But when i run the node, i get the following error.
<...
ashwath1993
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1
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Image registration with ground plane for surround view
I am currently working on a project which which involves surround view.
I have 4 fish eye cameras and are fixed at 4 sides of a car.The fish eye cameras are corrected for radial distortion.
After ...
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Obstacle avoiding by Pi camera [closed]
I designed a mobile robot with my colleagues for our graduation project, the purpose of it is to detect mines (metals) in a specific area
We are programming the robot using Python on Raspberry Pi 3
...
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link to opencv2 in kinetic
Hello! I am using ROS Kinetic on Ubuntu 16.04 Xenial 64bit. I have installed both opencv2 (by libopencv-dev) and opencv3 (by ros-kinetic-opencv3). A project of mine depends on cv_bridge, the problem ...
mikegao88
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Transport Image tutorial issue: subscriber doesn't show image
Hello everyone,
I tried to do the tutorial " Running the Simple Image Publisher and Subscriber with Different Transports " image_transport/Tutorials
but I encountered an issue.
When I run ...
Hysis
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1
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Converting Image Coordinates to (x, y) Position for Robotic Arm
I have a Robotic Arm with a camera mounted above it looking down at a slight angle.
Assuming I know the height of the camera, the angle of tilt and the small distance from the center of the robot ...
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error in adding extra module in opencv
hi guys
i am trying to add opencv_contrib module to my existing opencv and i am getting following error, please help
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zubair
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what is core?
hi guys, i am using opencv with ros environmnt and after many trials ,, a file named core is created !! and is of size 185 MB and i am wondering what is the need of this ??? its just got generated ...
zubair
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New problem linking OpenCV Indigo Cplusplus node
Indigo, Ubuntu 14.04 (Linux Mint 17.1)
I had a problem the other day that turned out to be missing find_package(OpenCV) so that was resolved.
But I have a new one. I have a better tracking test that ...
burtbick
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1
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Scale problem with monocular visual odometry
Is monocular visual odometry able to estimate relative scale? Say I have a sequence of 10 images that are taken on a single track each 1 m after the previous. Can some mono odometry method distinguish ...
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transform (x,y,z) coordinate from kinect to /map frame using tf
Hi, I'm tracking an object using a kinect and trying to publish the tf transform of that object in a "/map frame. I'm able to return the object's x, y and depth data using OpenCV. However, I'm ...
cluelessnigerian
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4
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convert pixel values to meters
hello guys ,
this is how i am getting x and y from the blob, can anyone tell me how can i convert these posX and posY values in meters or centimeters ??
...
zubair
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Listener does not update
Good afternoon friends
I can get an image of the camera from the gazebo: /camera/image_raw. But if you change the qr code, the listener does not update.
Can anyone help me with this?
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icarold
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Problem Listener with
Good morning people
I did a listener for the camera/image_raw node republish (camera/image_test, but the following error appears: Client [/ QR_Listener_5598_1492006578702] wants topic /camera/...
icarold
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190
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Google's 'Tango' - How it works and what's special about the hardware?
I'm looking for a good breakdown and explanation of Google's 'Tango' AR platform. Specifically how the hardware works together to generate depth maps and the SDK's use of it.
I know the hardware ...
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Is ROS Kinetic compatible with libopencv-dev-2.4.9?
The REP link suggests to use opencv 3.1.x with ROS Kinetic. However, since the system package libopencv-dev 3.1.x version isn't available in the upstream ubuntu repository yet, I had installed ...
sam26
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How to check lane departure in OpenCV?
I'm using OpenCV 3 in Python 2.7 on a Raspberry Pi 3. My project's aim is to build an autonomous lane departing robot that can detect the two lanes on its sides and continuously correct itself to ...
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Kinetic error: opencv2/core/core.hpp No such file or directory
I am working with ROS kinetic on ubuntu 16.04
after a system update with Software-Updater i get an error while catkin_make-ing.
worked like a charm before.
...
Stoerakustik
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find position of object in a bag
Hi guys,
I need to find(estimate) the 3D position of the 'people in the scene' -- (this is in the bag file) with respect to the camera.
My code is : (I didn't write it)
...
Rai
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2
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How to use arbitrary version of OpenCV
Hi, i have ROS Kinetic installed and it comes with OpenCV. I also have the latested OpenCV that i downloaded from github and installed in /usr/local.
The following code that i wrote will always use ...
sep_vanmarcke
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6
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Python OpenCV namedWindow and imshow freeze
Hi there,
I try to view a subscribed image via cv2.imshow() like the following:
...
UllusParvus
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Getting started in the world of drone programming
Hey guys, I'am new in this site but i think i will pretty active in the next few months!
My idea is program a drone so that it follows objects alone. I have some programming experience but i don't ...
sep_vanmarcke
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1
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2
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opencv with ros kinetic
Hello,
I'm trying to use opencv with ros kinetic. I can run catkin build successfully, but when the method ...
bennypi
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1
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OpenCV3 - Install extra-modules ROS Kinetic
Hello everyone !
I know there's already a post about this subject : http://answers.ros.org/question/229246/how-to-build-opencv-extra-module-while-opencv-is-installed-with-ros/ but there's no answer.
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matt27110
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485
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detect post-it from an image of a visual management Board [closed]
'm trying to detect all the post-it in an image and get them into an arrayList. I tried many alternatives (removing backgroud -> detecting contours, haar Cascade
classifier, detecting rectangular ...
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Send a video from ROS to OpenCV app
Hello,
I want to publish a .avi/mp4 file through ROS to my OpenCV app. How do I do so?
Originally posted by Zig on ROS Answers with karma: 1 on 2017-02-22
Post score: 0
Zig
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2
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Problem viewing images using python-opencv
I have trouble viewing color images from R200 realsense camera using the python-opencv interface.
The window is blank when I run this script.
When I comment out'cv2.namedWindow("Image window"...
pnambiar
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CMakeLists pkg-config opencv C++
I made program with "opencv2/nonfree/features2d.hpp" like this include.
#include "opencv2/nonfree/features2d.hpp"
When I compile the program, I ...
sora
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Noise Image_raw from video stream
I have 2 cameras looking at an object, estimating the transformation between two camera images using OpenCV feature matching. I have ROS driver for 2 cameras (gscam). When receiving new image topic (/...
tn0432
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Problem even catkin_make'ing my ROS Images to OpenCV node -- Library issues?
I am trying to create a node that will help me take an ROS Image and convert it to an OpenCV image.
I am following the "Converting between ROS images and OpenCV images" tutorial.
At step 9, ...
ateator1
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1
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3
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Writing a Simple Image Publisher (C++) tutorial Segmentation Fault
I am running ROS Kinetic full desktop install on Raspberrypi 3b running Debian Jessie. These are fresh installs with nothing else added. I followed the Simple Image Publisher/Subscriber tutorials ...
FAD0
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2
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1k
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Stereo Camera calibration with different camera types
I'm trying to perform stereo camera calibration, rectification and disparity map generation. It's working fine with normal sample data. However, I'm trying to use the dual cameras on an iPhone 7+, ...
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Update OpenCV version in ROS
Hello,
I checked my OpenCV version discovering that is 2.4.8.
I want to update it to 2.4.13 (at least 2.4.9) but I don't want to stop to use it in ROS Indigo too.
Since OpenCV is not a system ...
marcoresk
5
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2
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2k
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Transforming Point Cloud to get Top Down Image [closed]
My task:
I have a task where I am asked to track parcels(carton boxes) of different dimensions moving on a conveyor. I am using Asus Xtion pro camera mounted on top of a conveyor in any inclined ...
- 151
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Access AR.Drone camera with OpenCV while connected to ROS
Hi,
I am having an issue where by I am unable to connect to the AR Drone camera when the drone is connected through ROS using the ardrone_autonomy ardrone.launch.
I think the issue is due to the fact ...
pyro229