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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Poor accuracy of hand eye calibration when using vanilla Tsai's method
I’m working on the hand eye calibration for the robotic arm. I attached the camera near the tip of the robot (or end effector) and took around 40 pictures of an asymmetric circles pattern. I ...
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Accuracy of monocular visual-inertial odometry
I am currently considering to use monocular visual-inertial odometry (VIO) to localize a smartphone relative to a known object. Now, what I would like to understand is, what kind of accuracy I can ...
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real-time stereo vision system for long range (up to 100m) depth estimation
I want to implement a FPGA-based real-time stereo vision system for long range (up to 100m) depth estimation. Also, I want to use two ip cameras in the system. I have calculated depth error using the ...
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Is it possible to calculate a homography matrix for any 2 views?
I've been experimenting with opencv to estimate the homography matrix between 2 images captured with my computer's webcam. I have noticed that when the 2 views are not very far apart (that's when I ...
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Stereo Rectification when Extrinsics are known
Suppose I have two cameras $C_1$ and $C_2$ arranged in a stereo configuration. Let us assume that the camera is free of distortion with ideal intrinsics and that the camera extrinsics $R$ and $t$ are ...
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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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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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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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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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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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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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What is the baseline of a RGBD camera?
I'm looking at some ORB SLAM2 settings where there's a parameter for "IR projector baseline times fx". Could someone here explain what exactly is the baseline of an IR projector? Is it the distance ...
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Decrease minimum depth of a RGBD camera
I have a Kinect camera which has a minimum depth of 0.5m and I'm trying to find a way to decrease it to around 0.2m for near-depth detection. Does anyone know how this can be done? Can a macro lens be ...
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robot Hand Eye Calibration problem
I am trying to understand the implementations and the relative performance of various classical and new Hand-eye calibration approaches.
Note: The following discussion assumes implementations are in ...
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Stereo-Calibration with Variable focal cameras
Is it possible to perform stereo-calibration with cameras having variable focus? and if so, how is it done basically?
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hand-eye calibration for wheeled mobile robots
I am new to robotics and working with a wheeled mobile robot with one Kinect mounted on top of it currently.
The robot knows its position in the environment via some means.
I encounter one problem. ...
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Algorithm for orientation (pan/tilt) towards a moving point
Main Question:
note: The code in this question is pseudo-code, I'm using Python, but my pseudo-code is a mix of Python and C++.
I have a camera on the top of my robot's "head" which has pan and tilt ...
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Stereo vision setup to obtain depth map
I am currently working on a project that requires me to obtain depth information and point cloud map of objects in an indoor environment ( roughly twice the size of a normal room). I would like to ...
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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 ...
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How does a measurement model for camera based PNP work?
I am trying to write an EKF that can estimate the covariance of a pose estimate, where the estimation is being done by a PNP algorithm and 3D-2D correspondences in images. Although EKF based camera ...
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Is the distortion introduced by a lens protector significant in practice?
I have a computer-vision application I made to localize a robot in a room; the software has been in use for a while and is working fine.
When I calibrated the camera and got the intrinsics and lens ...
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Depth of view for a hypercatadioptric camera
I am trying to determine the depth of view for a hypercatadioptric camera (camera lens system and a hyperbolic mirror) based on 1.
The following illustration seems pretty clear. For an image point $...
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Marker pose flickering one axis from -4 to +18 when camera is not moving
I'm taking a sequence of frames from intel real sense and detecting april tags, I noticed the axis is flickering even camera is not moving. euler angle y axis is changing(visually and numerically) ...
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How can I change the dicitonary of aruco markers in aruco_ros package to the newer DICT_4x4 dictionary?
The arcuo_ros package by pal_electronics uses old dictionaries of aruco markers, the markers of these dictionaries are coded in uint64_t integer in the code file of the dictionaries dictionary.cpp (...
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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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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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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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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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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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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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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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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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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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Which algorithms to locate a static 3D object relative to a moving camera/IMU?
I am using typical setup with camera and IMU as found on a smartphone. Using this, I would like to estimate the relative pose between the camera and an object (for simplicity, let's say a cube). The ...
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Mini Recorder from RC Heli Parts
I had a RC Helicopter (with video,picture, and audio taking capabilities) that recently "died" (unrelated to short circuit). The reciever board short circuted, but the board that sent data to micro-sd ...
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