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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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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 ...
satan 29's user avatar
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2 votes
0 answers
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How do I use the live video stream from my arduino camera (connected by serial), to run with my OpenCV python ball tracking code?

My objective is to have the arduino camera, just to act like a webcam, and have my laptop run a ball tracking script on it. The ball tracking script already works with my laptops camera, and it can ...
Abhinav Sundar's user avatar
2 votes
0 answers
332 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 ...
Daphnee's user avatar
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1 vote
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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 ...
Idan Aviv's user avatar
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0 answers
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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: ...
Mhd Afz's user avatar
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1 vote
2 answers
176 views

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 ...
user37201's user avatar
1 vote
2 answers
925 views

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 ...
Mona Jalal's user avatar
1 vote
2 answers
187 views

OpenCV camera rvec tvec to ROS world pose

I'm detecting Aruco tags using the OpenCV bridge and I have tvec and rvec returned with the tag pose related to the camera using OpenCV axis notations. I would like convert them to a ROS pose related ...
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89 views

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 ...
senSMEM8's user avatar
1 vote
0 answers
199 views

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....
Alexander Soare's user avatar
1 vote
1 answer
351 views

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/...
bob's user avatar
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Interpreting results from Camera Calibration?

I used OpenCV's findChessboardCorners on a few checkerboard images (40~) and about 27 seemed to find the corners accurately. How does one proceed from here? Do I calculate the reprojection error over ...
r4bb1t's user avatar
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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 ...
Jogging Song's user avatar
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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 ...
franzele's user avatar
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1 answer
27 views

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 ...
masteryoda436's user avatar
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12 views

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? ...
Ben's user avatar
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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/...
Meriem Ghrissi's user avatar
0 votes
1 answer
72 views

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 ...
Jazx Jazx's user avatar
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0 answers
92 views

Error: Could not demultiplex stream video player opencv depth camera

Video player gives "could not demultiplex stream" ...
Vrushab Jain's user avatar
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0 answers
27 views

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 ...
kilianf's user avatar
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How to transform the detected target pose into the pose in the camera coordinate system in Gazebo

that is my code ...
chan mlen's user avatar
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0 answers
135 views

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 ...
Onee's user avatar
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0 answers
100 views

I am trying to use opencv_cam pkg in ros2 humble with a csi stereo camera imx219-83 in a jetson nano and I get green screen

I am trying to use opencv_cam in ros2 humble for a csi stereo cam in a jetson nano. When I run the node : ros2 run opencv_cam opencv_cam_main ,it publishes the ...
Thiago Blanco's user avatar
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0 answers
75 views

How do I use a CSI camera with ros?

I am using Jetson Orin Nano connected with raspberry Pi V2.0 Camera. I am using gstreamer pipeline to get the camera feed. It works fine with g++ build and python but as soon as I try to build it with ...
lonewolf's user avatar
0 votes
1 answer
129 views

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 ...
Franci's user avatar
  • 1
0 votes
1 answer
127 views

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 ...
noobcoder's user avatar
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0 answers
81 views

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: ...
nebula's user avatar
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0 votes
0 answers
49 views

multiple video streaming

I'm currently experimenting with video stream opencv. But,I think I can only stream one video at a time.Is it possible to stream multiple videos at the same time?If there are other packages that would ...
whvauwgruivariuvba's user avatar
0 votes
2 answers
28 views

Which single board computer should I chose?

Hi ros community I' m working with ros to make a robot which can go itself with image proccessing. I am using lots of hardware in this project and I used pcduino V3 until this time. But I want to ...
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1 answer
470 views

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 ...
skpro19's user avatar
  • 314