Questions tagged [cameras]

A camera is an optical instrument for recording or capturing images, which may be stored locally, transmitted to another location, or both.

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How to test moveit handeye calibration?

I have a KUKA iiwa 14 and a realsense D435i camera. I calibrated the system using a hand-to-eye configuration in Moveit! Hand-eye calibration package. But I would now like to test the accuracy of the ...
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[Raspberry Pi]: ROS 2 Humble on Ubuntu 22.04 Server: v4l2_camera reports "Failed stream start: Invalid argument (22)"

I have ROS2 Humble installed on Ubuntu 22.04 Server (64-bit) on a Raspberry Pi4. When I run the v4l2_camera node it finds my Pi Camera (v1.3) but then complains: Failed stream start: Invalid argument ...
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Camera Calibration Matrix accuracy

When we do camera calibration, we have to find calibration matrix $M$, which is found by first finding extrinsic matrix and then intrinsic matrix. To validate the accuracy of calibration matrix, we ...
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Robot-to-robot relative position over time?

I have 3 robots and I know the starts and end coordinate of each of them. For example for Robot 1 I have Xr1, Yr1 and Xr2,Yr2 coordinates pair , same for Robot2 and 3. I have lateral cameras so can ...
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What is Rotation when pose is looking back?

I've model a relative pose between two cameras. $T_0$ is origin and $T_1$ has the relative pose. The $Camera_0$ is facing a the map point $X$, and I can get a vector $v_0$ from $Camera_0$ toward $X$. ...
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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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1 answer
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How to get transform between two fixed frames using a camera

In my task, I have two manipulators: one 6 dof robot (Manipulator 2 as shown in attached link picture), and one passive arm (Manipulator 1 as shown in attached link picture). Both the frames 1 and 2 ...
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Docker container shows the same CPU % when running GigE camera with different FPS

I'm running a docker container that is running a GigE Lucid Vision camera with hardware triggering. I'm using ray to run the camera and process the images. I'm doing it to benchmark the application ...
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How to find the camera matrix and distortion matrix from the given data

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Essential Matrix constraint violated, computed using numerical libraries only

Lets say that I have eight pairs of correspondance points taken from two images (left and right). Also, I know the intrinsic matrix (K) of both cameras (is the same). I'm trying to find the Essential ...
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Uncontrolled drift of Visual Inertial Odometry

I'm trying to use the VINS-Fusion package to obtain odometry for a quadcopter. The primary sensor is an Intel Realsense D435i. I've calibrated the camera and IMU extrinsics using Kalibr. IMU ...
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Sending Universal Robots UR5e to specific place Using Camera

I have a UR5e installed with a simple camera on its end effector. The robot is at a known position (Cartesian pose/angles and joint angles) Using the camera I took a picture of a QR code and got the ...
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How to program a custom microcontroller to USE CUES FROM A PC to change the position of a servo motor? (Without using Arduino/Raspberry Pi)

I want to program a custom microcontroller that ideally connects to a camera and performs some sort of image analysis and do something(like change the position of a servo motor). The initial idea is ...
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How to make a synchronized LiDAR/Camera rig for Autonomous Driving research?

I am just starting a research project at my university involving sensor fusion between a Camera and a LiDAR device to detect and localize cars around our vehicle (bounded boxes around cars in 3D point-...
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3D LiDAR synchronization with RGB Camera

There's a general procedure for estimating projection transformation between camera and 3d LiDAR but there's a secondary problem which is associating pixels with depths in a grid which isn't uniformly ...
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Mobile robotic arm camera position

I'm working on my graduation project which is a mobile robotic arm that performs pick and place tasks. I wanted to know the possible ways to mount the camera where i can reach the desired destination ...
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six cameras selection for jetson xavier

What six cameras do you recommend for a university project using a jetson xavier nx? I am getting into self driving from a software point of view and camera selection becomes very difficult for me. I ...
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Searching for object in an unknown environment using ROS

Using ROS, I'm trying to build a robot able to search for specific objects in an unknown environment. Right now, I'm experimenting with a mobile robot in a simple gazebo maze, using a LIDAR for ...
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ROS Camera Calibration for Webcam - Not working

As a part of learning, I am trying to perform Camera calibration with my laptop's Webcam. I am really new to this process. I will explain everything about how far I have come so far, and where I have ...
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2 answers
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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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Number of pixels required to identify something

When using an RGB camera, what is the minimum number of pixels of an object that you need to identify something (theoretical or rule of thumb)? The image would be taken out in the wild with a complex ...
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1 answer
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How to calculate extrinsic calibration of a non-overlapping multicamera rig?

thanks for taking the time to check my question. Firstly, let me describe the current configuration, I am using 4 cameras that produce non-overlapping images and the goal is to calculate their ...
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Cheap global shutter cameras with external synchronization

Please recommend cameras for multi-camera setup satisfying the following conditions: Relatively cheap (up to 100$ per camera). Global shutter. No filters on lenses or pixels. Resolution of 1 MP or ...
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ROS Publish Stereo Image From 2 USB Cameras

I have two monocular USB cameras and I want to use ROS to make it a stereo camera. I am having a hard time finding a ROS package that consumes 2 monocular camera image streams and publishes a depth ...
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1 answer
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Use 2 Cameras as 1 Stereo Camera

I have one Picamera and one normal USB Webcam and would like to use them together as one stereo camera. Is this even possible as the 2 cameras aren't exactly the same? I would like to use them in ROS ...
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ROS Webcam Stream Really Slow

I am trying to stream the images from my camera to a VM via ROS. Here is my setup: Raspberry Pi 3B+ with Picamera v2. It is running ROS Noetic with cv_camera_node ...
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1 answer
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Visual Odometry terminology: Scale, Relative scale, absolute scale

I'm watching a MOOC about Machine Vision for Robotics, but I really do not know the meaning of some vocabulary of this domain. For example, What does the professor mean when he says this: However, we ...
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Trouble aligning/calibrating camera with laser scanner

I have a robot which has 2 multi-spectral cameras and 1 laser scanner attached. In the end I would like to have the images from the cameras aligned with the scanner so that I can have spectral ...
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2 answers
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Is two cameras equivalent to Stereo camera setup?

I have two webcams, which are mounted close together. I plan to use them to find out the true depth of certain pixels of images. Suppose I use a standard multi camera calibration setup and find out ...
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IMU-Camera Senor Fusion

I am working on fusing IMU and Camera Sensor Fusion for the Drone to precisely land on the target location. With the Camera, I am tracking the April Tag which is on the ground. This gives me the x,y,z ...
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What are the parameters that I need to consider when figuring out the horizontal viewing distance of a camera mounted overhead for effective tracking?

I am currently working on developing a hybrid Indoor Positioning system where images from an overhead camera will be used to identify and track people. I am new to the field of visual tracking and a ...
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2 answers
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3D reconstruction of a moving object from two camera video stream

I have two synchronized video streams of a moving deformable object from two different cameras (same brand/model type) but two different views. How can I do the 3D reconstruction of this moving object?...
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How well does object detection transfer from simulation to reality? [closed]

I'm looking to learn more about this sim-to-real gap. I'm new to the concept and am trying to understand what to look for. Most notably i'm curious about how well an object detection algorithm trained ...
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Size of smallest feature from pixel depth resolution

How do I get the size in mm of the smallest feature a depth camera can detect? Known variables are: distance from the target (for instance 1 meter), depth resolution in pixels (for instance 1280 x 720)...
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How can I calibrate 3 cameras without knowing global pose of the object & camera locations? How can I find the pose of each camera wrt the first one?

I have camera feed (in the form of RGB images) from 3 cameras with partially overlapping Field-of-view i.e. for the time stamp 0 to 100, I have total 300 frames or say synchronized 100 RGB frames for ...
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What does the normalized image coordinates imply?

In VSLAM or visual odometry, we use a camera matrix P to transform 3D scene points to 2D image points. When using homogeneous representation, we may choose the image coordinates as the normalized ...
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1 answer
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Automatic License Plate Recognition System in Highway

We are working on a computer vision project where an automated robotic system will be deployed on a 3-lane highway. We are using a bosch IP camera (I don't remember the model exactly, but it cost ...
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1 answer
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How to find visual odometry by video from cellphone camera mounted on robot?

I am writing codes in python for visual odometry from single camera. I used cell phone camera for testing. I took video of 35 sec with camera moving. I used code below to read first image ...
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Camera Pose Estimation

What is the minimum number of point correspondences required for camera pose estimation given the perspective projections of points with known world coordinates?
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What is the definition of the phrase "ego robot"?

What does the phrase "ego robot" mean? I see it used in the context of multi robot systems like in the paper Game Theoretic Motion Planning for Multi-robot Racing by Zijian Wang, Riccardo Spica & ...
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What type of camera parameters are ideal for image processing on a moving platform?

What type of camera or camera properties should I look for that would be ideal for performing image processing in a moving environment? I'm researching the sensor requirements for processing video in ...
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Determining Orientation of a Robot Relative to a Line on Table

I am currently busy with a robot that needs to obtain it's orientation relative to a line seen by a camera. At the moment, I am using Hough lines to obtain a gradient for the line, but the gradient ...
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Hint regarding Localization & Map Scaling

I just started with mobile robotics. I'm trying to do a collaborative system between a mobile robot and a ceiling camera (Raspberry). They should do all tasks as a "team". Means Calibration, ...
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Intel RealSense Depth Camera D435i Wide Imager questions?

I have just ordered my d435i and while it was not intended to do NDVI I read the data sheet and noticed it had seperate image sensors, it is possible to read the IR image from either left, right or ...
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Use Realsense camera to get the camera image

I have to use LIDAR in my project. I was searching for some LIDARs with a camera and came across the Intel RealSense d400 series. I know it has a camera but please suggest a way to use that camera ...
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Planar Robot Boundary Detection

I am tasked with building a robot that needs to localise and navigate itself on a rectangular surface (like a large desk). The rectangle's shorter sides will be marked with a red tape (or with two ...
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How to derive the camera trajectory from ICP

This may be a very simple question so please bear with me... Suppose I have a stationary object and point clouds, $n$ $(x,y,z)$ points, of that object taken by a moving camera at time steps $t_i$, $...
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Collaboration of mobile robot and survaillance camera - classic localization (still) needed?

Just started with the topic of mobile robotics.. so I'm still into concept making and little programming, but have not setup everything or tested at all. I got a (differential) mobile robot (lego ...
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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 ...
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How to plot the 3D camera trajectory from a VSLAM output

I am totally new to VSLAM algorithms and would want to plot the path followed by the moving camera. I am using the open source implementation of ORB_SLAM2 for a rgb-d camera on benchmark dataset. The ...