Questions tagged [computer-vision]

The goal of computer vision is an automatic extraction of information out of images. It includes methods for acquiring, processing, analyzing, and understanding images and high-dimensional data from the real world in order to produce numerical or symbolic information, e.g., in the forms of decisions. The image data can take many forms, such as video sequences, views from multiple cameras, or multi-dimensional data from a medical scanner.

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137 views

How can I receive Genicam packets from a device in a docker container?

I installed a command line tool which accepts genicam packets from a device as input into a docker image. If I use the option --network host in the ...
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280 views

Triangulation from calibrated stereo rig

I am using a stereo rig to do SLAM, calibrated using the MATLAB Calibration Tool. I need to compute the 2D coordinates of a landmark using the observation model obtained from triangulation (the images ...
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19 views

Disparity error in active light stereo systems?

Based on this relationship, if we have to estimate the 'disparity error' of a stereo system which uses active light on the scene - can we estimate the disparity error to be very small? According to ...
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1answer
29 views

Facial Detection combined with Path Planning using Kinect Sensor

I am planning to use a Kinect Sensor on a mobile robot for path planning based on facial detection. Assuming I am able to detect the faces of 5 individuals in a room (both the environment and the ...
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27 views

How to perform Image alignment using pyramid levels

To gain some confidence, I want to implement the camera tracking (optimization problem) discussed in Semi Dense Visual Odometry for a monocular cameraJ Engel, J Strum, D Cremers $$E(\xi) = \underset{...
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31 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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Undo pitching effect of camera when pose (y-axis) is near 90 degrees?

I am using KITTI odometry dataset whereby the camera's axis is pointing X (east), Y (down) and Z (north). It also contain the frame to frame poses of the camera (first pose is fixed as the map frame). ...
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261 views

How does marginalization of variables effect least squares SLAM energy function?

Consider a simple example of Bundle Adjustment where I have robot and landmark poses $x = \left[ x_p \text{ } x_m\right]^T$ and measurements given by $z$, such that a simple factor graph can be ...
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101 views

Monocular SLAM depth reconstruction

I am trying to derive the inverse depth equation used in monocular SLAM algorithms. Specifically the equation 8 of the ORB SLAM paper I am very close, except I do not understand where the (u_j-c) ...
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0answers
81 views

Consitent Scale in Monocular pose estimation

I just wanted to know if scale is conserved across multiple images, when doing a process such as monocular odometry. I know in reality the scale tends to drift over time due to accumulation of small ...
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583 views

Correcting GPS track with visual odometry (sensor fusion)

I am trying to build low cost and precise outdoor positioning. I explored NS-RAW with RTKLIB - this would be doable but probably will need either a base station to get the correction data for rover or ...
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1answer
39 views

How is the depth estimation done in DTAM / LSD-SLAM (direct VSLAM)?

I know that DTAM and LSD-SLAM both employ the photometric error between two keyframes to estimate the image depth. But I don't know what the photometric error describes precisely. In the DTAM paper, I ...
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32 views

How does inverse compositional Lucas–Kanade algorithm work?

I am trying to understand the Lucas–Kanade algorithm since I am reading a paper in which is applied the inverse compositional Lucas–Kanade algorithm, but in order to understand the latter I have to ...
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29 views

Intel Realsense Cameras for Object Avoidance and SLAM to go to destination

My goal is to make a UAV which can search an area while avoiding obstacles. I figured I would navigate using the SLAM and Intel Realsense D435i (a stereoscopic camera with an IMU built in), but all of ...
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28 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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112 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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51 views

Tracking object in realtime using depth image stream from a RGBD camera

I have an Intel RealSense camera which can stream RGB and depth image. Using those information I want to track an object moving on a table top. More specifically, I want to know position $(x,y)$ and ...
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94 views

How to update a new pose in iterative pose optimization problem?

There are multiple ways to update new pose in iterative pose optimization problem. The easiest one we often find in papers in robotics is as SO3 + translation Update on right \begin{equation} \...
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57 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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1answer
314 views

Pictures coordinates to robot coordinates

I have a picture on my C# software and the corresponding object in real world on 2d plane of motorized XY axis table. What I want is when I select a pixel on my picture, the motorized table should be ...
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151 views

Which Kinect to use for robotic arm pick and place application with object detection?

I am building a robotic arm for pick and place application. The robot is going to recognize several objects using the RGB feed from Kinect (will use a model such as YOLOv2 for object detection, ...
1
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1answer
268 views

Rotation composition When using Kalman Filter

I am implementing a Kalman Filter for the following situation. I have a camera set in a room that can detect the position and orientation of a marker (ARUCO) in the room. Therefore I have the ...
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269 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 ...
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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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198 views

How to change the orientation of an object w.r.t a scene?

I am trying to localize an object in a point cloud using ROS, PCL. For that I capture the scene and model using Asus xtion pro sensor. I use RGBDSLAMv2 for capturing the model. Then I use ICP (...
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14 views

Drone based CV via base station - power requirments

Currently computer vision based inference is impractical on a drone given the significant power draw. Is connecting a drone to a base station which does CV a viable solution to this issue? Has it been ...
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12 views

ModuleNotFoundError: No module named 'second.core.non_max_suppression.nms'

I am using Anaconda base environment for second.pytorch of ubuntu 16.04 after executing the following: nvidia-docker run -it --rm -v /media/yy/960evo/datasets/:/root/data -v $HOME/pretrained_models:/...
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19 views

Are there some papers or books that compactly elaborate the essential part of the multiple view geometry?

I am a novice to visual SLAM and computer vision. Recently I've read a paper "A micro Lie theory for state estimation in robotics" dedicated to introducing the essential part that necessary to ...
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0answers
20 views

get position of objects using ir

I originally wanted to make a shoddy vr system with two IMU's in two seperate right and left controllers, which their values could be sent over wifi to the game service unity so I can plot their ...
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20 views

Serial communication of IMU and Encoder arduino code

Pls, I need people to help me look at where I am getting it wrong. I test this code on Arduino ide and got the result I wanted but sending it to Matlab through serial communication, I obtained a ...
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1answer
29 views

Computing Essential Matrix from Fundamental Matrix

I have calibrated my cameras using OpenCV. I used cv.stereoCalibrate to get the E, and F matrices. I wanted to do a sanity check to see if the E matrix obtained is ...
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15 views

Bundle Adjustment for Monocular SLAM

I am confused with how monocular BA works in visual-based SLAM. Is there any tutorials I can do in openCV to provide me some visualization aid? Thank You.
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15 views

How is a point triangulated with SVD with 2 correspondences?

According to these slides, if you have 2 correspondences for one 3D point, is is possible to build a system of linear equations (slide 27): AX = 0 And solve for <...
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25 views

What is the jacobian of an image lookup function?

I'm trying to solve a computer vision problem whereby I wish to use Levenberg-marquardt non-linear optimization to solve the following equation: Whereby xi is the x,y coordinates in the image, I ...
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16 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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18 views

Single Camera + Laser Projector Triangulation

I want to combine a laser line projector (projects a laser plane) and a single web camera to determine the X, Y, Z position of the laser point. I am slightly confused as to how to use the fact that we ...
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32 views

Rescaling a local Map in VSLAM (orb slam)

I am trying to inject metric scale into a vslam algorithm, namely the popular ORB-SLAM2. I have read several papers(1,2) whereby people have successfully calculated scale factor from the actual height ...
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39 views

Use Camera Calibration Matrix without Toolbox

I am doing this little project where try to calibrate a Raspberry Pi Camera. I use Matlab and I do not want to use the Calibration Toolbox (!). The algorithm I use is the direct linear transformarion ...
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24 views

Which is the recommended depth estimation method for under vehicle scanning?

There are many ways to estimate depth e.g. Structural light based solutions Time-of-flight (ToF) cameras LiDAR Stereo cameras Computer Vision image based methods Monocular models such as monodepth2 ...
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15 views

Creating a Raspberry Pi drone without Navio

I'm very interested in developing software to run an autonomous drone. Preferably using the raspberry pi. There is a lot of information on the internet, much of it is outdated and is extremely ...
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0answers
17 views

Detecting pieces of a Version 1 QR code and processing the assembled version

I am building an aerial robot that needs to be able to detect pieces of a QR code (examples below) and combine them to process the information contained in the fully assembled QR code. I don't have ...
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24 views

How to make x variable change each time and read its value from txt file

I am working on my undergraduate project and this is my first time in using use python to control parrot bebop 2 drone and use BCI or BMI technology. I have x variable (int) and I want to read its ...
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1answer
63 views

what is ultrasonic based slam

i am confused about SLAM implementation, and i need your advise to organize my mind. Fist let me say that i have to generate 2D map, what is in this case the SLAM input? is it like (x1,y1),(x2,y2)...(...
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182 views

estimate accuracy of (aruco) marker position tracking

I'm planning a concept for calibrating a robot model. For this purpose I want to use computer vision approaches. Since I'm not that experienced in that field I have some basic questions on the ...
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18 views

Hunt for fast plane extraction algorithms from sparse map points

My input was a set of sparse 3D map points(landmarks) maintained by SLAM algorithm, z-axis of the world frame permanently points to the negative direction of the ...