Questions tagged [opencv]
OpenCV (Open Source Computer Vision) is a cross-platform library of programming functions for real time computer vision.
472 questions
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Difficulties transforming binary mask from camera frame to world frame
I have 2 RGB cameras in Gazebo11 looking at the same scene from different locations. I threshold the floor space and create a binary mask with white being the ground (free space) and black being ...
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Estimate 3D location of a tracked point with Known Camera parameters and Distance
I want to estimate the 3D point of X̅₂,
X̅₂ = [ X₂ Y₂ Z₂ ],
by using known variables:
X̅₁ is at world origin,
camera intrinsics K,
camera extrinsics w.r.t. X̅₁, namely [R₁ ∣ t₁],
...
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42
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ROS2 Jazzy TF2 delay causing docking pathing issues
I am currently working on a mobile robot using ROS2 Jazzy with the Navigation2 docking server, along with Ros_ArUco_Opencv for ARTag pose recognition. I am seeing a delay between movement of the ARTag ...
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cv_bridge.h not found ROS2
I need cv_bridge on my cmakelist.txt. Cmakelist shows a path for cv_bridge.h, however there is no file on that name at that path.
I have opencv 4.5.4,ros2 humble.
I tried to install cv_bridge by ...
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ROS Melodic ORB SLAM 2 Map point vector is empty
I am trying to run ORB SLAM 2 with frames being published of a video I need to map however all parameters I have tried have lead to no features being detected even with some aggressive parameters as ...
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42
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Nvidia Isaac ROS Visual SLAM with OpenCV
Hey Robotics Community,
i successfully completed the Tutorial for Visual SLAM:
https://nvidia-isaac-ros.github.io/concepts/visual_slam/cuvslam/tutorial_isaac_sim.html
Now i want to show the colorful ...
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AttributeError when trying to reinsert modified images into ROS2 bag file with Python
I'm currently working with ROS2 and Python to process image data stored in a ROS2 bag file. My task involves extracting images from the bag, performing modifications, and then reinserting them. I am ...
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Create self-contained standalone ROS1 application for Windows
I created a ROS Noetic package that grabs data from some cameras and performs pose estimation of objects in the field of view (using OpenCV). Simultaneously, IMU data is measured and fused with these ...
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cv2.stereoRectify works only when the rotation and translation are from camera 2 to camera 1
I am using the euroc-mav dataset to create a disparity map from stereo images: https://projects.asl.ethz.ch/datasets/doku.php?id=kmavvisualinertialdatasets.
In this dataset the cameras are already ...
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Calculate disparity for matching feature points
If I have matched a pair of feature points, could I calculate its disparity by simply subtract the u coordinates(uL - uR)? And could use this disparity to calculate the depth for this 3d point?
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i want to run an image publisher in ros2 using opencv but this error apppears i am working with ros2 humble
when i run this qrie@qrie-HP-Laptop-15-rb0xx:~/dev_ws$ ros2 run cv_basics img_publisher
i get this error ModuleNotFoundError: No module named 'rclpy._rclpy_pybind11'
The C extension '/opt/ros/humble/...
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Video from dron camera to RTSP
I am a newcomer to using ROS and am facing the challenge of obtaining a video stream from the camera topic of my robot in Gazebo and transmitting this video via RTSP. I have attempted to use the gi ...
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Error: Could not demultiplex stream video player opencv depth camera
Video player gives "could not demultiplex stream"
...
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opencv StereoSGBM disparity parameters
In my setting I am using a stereo camera which has a baseline of b = 0.092m and a focal lenght in pixels of fx = 256.667.
So that when I want to constrain my setup to detect points up to a maximum ...
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14
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ArUco Markers Distance Estimation Accuracy Difference
The distance estimated (in cm: Because input size of ArUco Markers in cm too) using the code line after importing math module:
...
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ros2- where is the data libopencv-dev
I want to find this github address.
(I cant find it,because main opencvs github has opencv/opencv -b 4,3,2,1)
Thank you.
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ROS2 CV2 imshow and publish in the same loop fails
I attempted to publish and display an image from a video using cv2 and ros2. Although the code compiled successfully, running it consistently resulted in a memory allocation failure. Could someone ...
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243
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Switching between 2 cameras (using opencv)
I have a manipulator in ROS and 2 cameras attached on it.
I want to switch the frames of cameras every 5 seconds
Both cameras work fine.
I do not want to close the window and reopen it (if it is ...
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Converting a ros2 bag of color raw images to image files or video
This is using ros2 Humble in Ubuntu 22.04 and native Python 3.10
Eventual goal: capturing depth aligned RGB and Depth streams from Intel RealSense D435 camera and converting them to RGB and Depth ...
- 203
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167
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reading depth in mm from ros depth image
I want to read a depth image from ros.
I subscribe to the /camera/aligned_depth_to_color/image_raw/compressed topic published by a intel realsense D435i camera.
I ...
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130
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colorize area of point cloud on a 2D image
I am projecting a 3D Point Cloud on a 2D image incoming as ROS 2 messages. Now, I want to fill the gaps between pixels from the point cloud, so that I can see an area, instead of single pixels and ...
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154
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Calibration of camera using ROS, without camera info
As part of a college project, I need to communicate with a TM5-700 robotic arm developed by Omron, and implement, for now, a pick and place pipeline. For that, I am required to access the camera ...
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Segmentation fault in cv::findContours call
I am struggling to debug a segmentation fault. Any help is appreciated! The node just crashes whenever I launch it and following is the seg fault I am getting when running through gdb:
...
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130
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Detecting door blockage using computer vision
I want to detect door blockage on a camera. Basically if the exit door is blocked by an object, it detects it as an anomaly. How can we do it? Is it possible to do it using OpenCV?
Remember, it doesn’...
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309
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Making sense of disparity values after applying `StereoSGBM` from OpenCV
I just started with Kitty Stereo Dataset (2015). The first thing I did was compute the disparity using the stereoSGBM class. And here is the rectified input images ...
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95
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WEBOTS - Connect a external Tkinter Script to main controller?
I have a WEBOTS Simulation with an automobile. Now while WEBOTS provides a camera overlay, I want to display the result of image processing along with sensor data in a comprehensive manner.
For this I ...
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Convert CameraInfo K & D to OpenCV format convenience functions?
Are there existing functions to convert from camera info arrays of K and D to intrinsic and distortion cv::Mats that can be passed into opencv functions like ...
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373
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Configuring ROS2 for OpenCV and C++
How to properly setup the ROS2 workspace (i.e., cmakelists and package.xml, etc.) for using OpenCV and C++ ?
I could not find proper examples for that.
Thanks in advance.
Originally posted by ...
Werewolf_86
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Vision programming with OpenCV
I am currently working on a project on NiryoOne which requires facial detection of a person through NiryoOne camera (ELP SONY IMX).
The code that I am using works on my laptop running Ubuntu. However, ...
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How to enable GPU-Features of Rtabmap
OS: Ubuntu 20.04
CUDA 11.6, CuDNN 8.4 (GPU is Nvidia Quadro T 1000)
OpenCV 4.5.5 with GPU support also for CUDA and also the opencv_contribs
currently using Rtabmap standalone, but I intend to use the ...
TurBot
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56
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CMake detects intended OpenCV+CUDA, but runtime does not use intended OpenCV version
CMakeLists.txt contains
...
MrOCW
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21
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Catkin_make failed to build opencv
Hello guys,
I want to compile a package (https://github.com/mjshiggins/ros-examples) with the catkin_make command from the catkin_ws folder, but it seems that the OpenCV header file is depreceated or ...
Petros ADLATUS
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Why would we solve AX=XB instead of just using the Kabsch algorithm?
I have a high precision stereo camera and a robot which are independent units (the camera is not mounted to the robot). I wish to compute a transformation from the camera frame to the robot base frame....
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578
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ROS2: How to publish cv Mat image?
I'm having trouble understanding how to publish a cv::Mat image in C++, and I can find very little documentation about this.
Here's my publish code. I based it on this tutorial: https://docs.ros.org/...
zjeffer
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upgrade opencv version in melodic
Hello,
i want to upgrade opencv version to over 3.4 in Melodic.
Melodic installs opencv 3.2 originally,
so I tried to uninstall opencv 3.2, and re-install opencv 3.4
But some packages which are ...
danekim
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1
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366
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Error when compiling cv_bridge in Raspberry Pi 4B with Raspbian buster and ROS Noetic
Im using Raspberry Pi 4B, with Raspbian Buster and ROS Noetic. When I tried to compile my catkin ws with a cv_bridge package I got the following error:
CMake Error at vision_opencv/cv_bridge/...
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92
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Noetic python raw Image publisher (from video)
Hi everyone,
I have spent nearly 2 full days with this problem now and have some extensive research, but just can't figure it out.
My apologies for being a burden, I ussually hesitate to waste anyones ...
USAotearoa
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45
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Image Subscriber Lags (despite queue_size=1 and buff_size=2**30)
Hi,
I have been working on a Python class that will allow me to spawn an object in gazebo, take an image of the object, and then delete that object, for a given number of objects that I provide. I am ...
jdastoor3
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171
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ModuleNotFoundError: No module named 'cv_bridge' IN windows10 running foxy
I was following this tutorial https://automaticaddison.com/getting-started-with-opencv-in-ros-2-foxy-fitzroy-python/ to implement a simple ros2 image publisher and subscriber. everything was built but ...
aniketwagh
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Does a stable library exist for docking robots using images?
I built a mobile base from scratch, and now I am focused on getting the robot to charge.
The robot is using an on-board webcam (and PC) to detect a QR barcode on the charger unit. Using OpenCV I find ...
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Implementing PID on a line following bot using turtlebot
I am using ROS melodic,turtlebot 2 on Ubuntu 18.04.
The idea is to create an environment consisting of lines as a path (slightly curved), and to program the turtlebot to follow the lines. Basically, a ...
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What is the exact format and size of Image() object?
I cannot figure out what is the exact format of the sensor_msg Image() file. When I issue the command:
rostopic echo /camera/image_raw
I get a massive output ...
Tejas Rao
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118
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Reflective surface
Have you encountered the problem of reflective surfaces for realsense camera (d435 or t265) and lidar (A1 or A2). I would like to know what are the ways to solve problems with reflective surfaces for ...
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990
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OpenCV and ROS2
I've checked all the related questions here and I still wasn't able to get this example to run. I apologize in advance if the solution was right in front of me and if that offended anyone.
Problem ...
mintybim
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Compress Image topic with h264 streaming for low bandwidth connection?
Hello,
I faced the problem that sending the video with big resolution (1920x1080) is very difficult even with image transport. The raw or compressed images are too bit for sending over the network (...
Yehor
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133
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Find intrisic camera matrix from gazebo model
Hello,
I made a my camera model in gazebo and I want to extract the intrinsic matrix to use Opencv matrix.
Here is my model:
...
xavier12358
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374
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Path planning for robot car on grid
I am currently doing a project as my hobby. I am trying to simulate a robot car in a grid arena. Below is the image of the arena:
The start point of the car is the bottom-right corner(dark green ...
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198
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Eliminate grey space around the saved map
I have mapped my Gazebo environment using the slam_gmapping node. On running ...
- 314
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509
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Need help in loading occupancy_grid map to OpenCV window
I have generated a map named map_1.pgm using map_server package. I want to display it in an ...
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