Questions tagged [opencv]
OpenCV (Open Source Computer Vision) is a cross-platform library of programming functions for real time computer vision.
472 questions
0
votes
1
answer
1
view
point grey camera withe jackal
Hi,
I am using the jackal for my university project.
I have attached a camera to collect images and am using the cv bridge library to get snapshots.
On the desktop and simulation environment, I use ...
rsmitha
0
votes
1
answer
1
view
Problem with OpenCV on Kinetic
I am finding a way to resolve OpenCV issue with ROS Kinetic. After trying using cvg_sim_gazebo package, the functionality is now ...
alfa_80
0
votes
1
answer
6
views
How do I change the version of a package being used? Specifically, I want to downgrade the version of opencv being used
I want to change the version of opencv I am using to fix a problem I am having, or to at least rule out the version update as the problem cause. The problem is described here.
Downgrading the package ...
dpoiesz
0
votes
1
answer
10
views
Using opencv tracking with ROS kinetic
Hey, i want to use the tracking packageof opencv3 contrib in my ROS package.
The tracking packagee seems to be installed correctly, i can find the tracker.cpp in my opencv folder and also use other ...
VAVROS
0
votes
1
answer
34
views
error: variable cv::cuda::GpuMat has initializer but incomplete type
I'm trying to use the CUDA implementation for OpenCV on the NVidia TX1.
Using cv::Mat, the minimal example below works, but with cv::cuda::GpuMat it returns errors when comiling:
...
WLemkens
1
vote
0
answers
711
views
How to make a line following algortihm for an A.R Drone 2.0? [closed]
I am trying to develop a line following algorithm where a drone will detect a bounding box and follow what is inside the bounding box.
I am filtering all the colors to only see the color white. Once ...
- 11
4
votes
1
answer
9k
views
Determine the relative camera pose given two RGB camera frames in openCV-python
I would like to determine the relative camera pose given two RGB camera frames. I assume there's overlap in field of view between the two cameras, what I am looking for ultimately is the rotation and ...
- 235
0
votes
2
answers
5
views
Install opencv_contrib Tracking package
Hey there I simply want to use the tracking package of the opencv3 contrib package in my ros kinetic.
I figured already out that in particular the tracking package is not contained in one of the ...
Markus
0
votes
1
answer
12
views
How to tell Catkin_make to use opencv with gpu?
Hi.
I have same trouble with this Having trouble using CUDA enabled OpenCV with kinetic.
My trouble is catkin_make is looking into only non-cuda function for ros-kinetic even I use NO_MODULE to tell ...
k_totoro
3
votes
1
answer
1k
views
OpenCV get topdown view of planar pattern by using intrinsic and extrinsic from cameraCalibrate
Originally I have a image with a perfect circle grid, denoted as A
I add some lens distortion and perspective transformation to it, and it becomes B
In camera calibration, A would be my destination ...
- 151
0
votes
1
answer
2
views
compile with different opencv
I would like to compile a ros package skimap_ros with a local version on opencv. All my attempts at overriding the libraries in the CMakeLists.txt have failed ...it keeps taking the opencv from /usr. ...
rnunziata
1
vote
0
answers
111
views
Drone Feedback: Object Detection / Color Detection [closed]
I have been working on a code where an A.R Drone 2.0 will detect color and put a red dot in the middle of the image. I am using streaming for the drone. The goal is for the drone to detect a white ...
- 11
0
votes
1
answer
59
views
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
1
vote
2
answers
1k
views
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 ...
- 111
0
votes
1
answer
4
views
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)
...
MukulKhanna
0
votes
1
answer
3
views
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
0
votes
1
answer
7
views
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
0
votes
1
answer
8
views
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
0
votes
1
answer
88
views
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
0
votes
1
answer
593
views
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 ...
2
votes
1
answer
643
views
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
2
votes
0
answers
333
views
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
0
votes
2
answers
137
views
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
1
vote
0
answers
40
views
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
0
votes
1
answer
5k
views
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
6
votes
1
answer
3k
views
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 ...
- 417
0
votes
1
answer
4
views
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
4
votes
1
answer
1k
views
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 ...
- 171
3
votes
0
answers
551
views
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
...
- 31
0
votes
1
answer
3
views
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
0
votes
1
answer
9
views
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
3
votes
1
answer
3k
views
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 ...
- 31
0
votes
1
answer
3
views
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
...
zubair
0
votes
1
answer
2
views
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
0
votes
1
answer
11
views
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
4
votes
1
answer
2k
views
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 ...
- 643
0
votes
1
answer
6
views
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
0
votes
1
answer
14
views
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
0
votes
1
answer
5
views
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?
...
icarold
0
votes
1
answer
5
views
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
0
votes
1
answer
191
views
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 ...
- 153
0
votes
1
answer
4
views
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
5
votes
1
answer
943
views
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 ...
- 51
0
votes
1
answer
22
views
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
0
votes
1
answer
6
views
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
1
vote
2
answers
25
views
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
0
votes
1
answer
132
views
Python OpenCV namedWindow and imshow freeze
Hi there,
I try to view a subscribed image via cv2.imshow() like the following:
...
UllusParvus
0
votes
1
answer
14
views
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
0
votes
1
answer
2
views
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
0
votes
1
answer
5
views
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.
...
matt27110