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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39 views

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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40 views

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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552 views

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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20 views

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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112 views

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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21 views

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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36 views

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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23 views

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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45 views

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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159 views

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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28 views

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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135 views

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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40 views

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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40 views

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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89 views

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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200 views

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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34 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 ...
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131 views

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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24 views

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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55 views

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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16 views

Motion Tracking with Arduino Controlled Camera Slider

I have an Arduino-controlled 3-axis camera slider and I'm thinking of implementing a motion tracker that makes the camera move accordingly on the slider. How feasible is this during a 3-month period? (...
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31 views

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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36 views

ROS2 Stereo View Fails And Stereo Image Proc Doesn't Show Anything

I have set up 2 Monocular Cameras as a stereo camera in ROS2. I successfully published the 2 rectified and calibrated images through the following formats: ...
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19 views

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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27 views

RGBD Camera Compatibility with ROS

I am looking for a good RGBD Camera that I want to use with ROS. Is there a way to know if a camera will work with ROS? Or is it that every camera is compatible with the usb_cam node? I want to send ...
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22 views

RealSense Python API: Construct BufData or frame

I need to call rs2_project_color_pixel_to_depth_pixel from Python with synthetic data. The data are generated in Python and do not come directly from the RealSense. ...
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8 views

Is there any way to know whether the disparity is negative without stereo rectification?

For one stereo camera, stereo calibration is performed to obtain intrinsic and extrinsic parameters during manufacturing. During the process of usage, intrinsic and extrinsic parameters may be changed,...
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1answer
16 views

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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11 views

How to spatially calibrate two FLIR thermal SC8000 cameras?

I have two FLIR SC8000 cameras and I do not know how to spatially calibrate them? I am doing stereo videography of a deformable moving object in a 1mx1m square. I also don't know what angle of these ...
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26 views

How can I calibrate 3 cameras and track the object using only synchronized cameras feeds from all the cameras?

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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404 views

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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34 views

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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38 views

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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1answer
66 views

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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2answers
80 views

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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1answer
93 views

How to get a wired live feed from camera to phone

I need a clear video live feed from a camera to an android phone. The connection does not have to be wireless because i have to use it without any internet. The camera and phone will be 2 or 3 meters ...
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1answer
183 views

Extrinsic calibration of a multicamera-rig mounted rigidly on a mobile robot

We have a set of 8 cameras mounted rigidly on a mobile robot. The cameras are forming an arc, which allows a 360º vision. I want the extrinsic parameters of them referred to the robot. Is there any ...
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1answer
48 views

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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1answer
180 views

How to do IMU and camera “sensor fusion” tracking?

I have some 50ms latency cameras at hand and a 800Hz IMU (gyro+accelerometer+magnetometer). I would like to know how exactly how I should do a sensor fusion of such an IMU and camera to fix the ...
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2answers
132 views

Vısual sensor.camera lenses with a field of view of more than 180 degree

What kind of camera models can be used for lenses with a field of view of more than 180 degree ? Is ıt possible if not why? Are fisheye lenses suitable for this purpose?
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1answer
133 views

Extrinsic Calibration Target Depth Camera

What's a good calibration object for the extrinsic calibration (rotation + translation) of a depth camera (no color sensor, only depth)? With RGB, people seem to typically use chessboard pattern or ...
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66 views

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 ...