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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24 views

Choosing cameras for stereo vision system?

I'm in the process of building a stereo vision system with YOLO detection. The system have to detect airplanes in far distance and also measure the depth from the airplane to the camera. I think ...
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0answers
27 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
30 views

Active Light Stereopsis: 1 Camera + Projector Vs. 2 Camera + Projector

What is the difference between using 1 Camera and a Projector and using 2 Cameras and a Projector for creating structure from motion? Is it that if we use only 1 camera and a projector then we will ...
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1answer
39 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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1answer
22 views

Depth images with undetectable outlines

I'm trying to capture depth images with a RGBD camera, but all of the images have undetectable outlines around objects: Is this expected from RGBD cameras or is mine a dud? It's an Astra Pro.
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1answer
159 views

ORB-SLAM pose estimation

I've been reading about ORB-SLAM and ORB-SLAM2, but I can't quite figure out how pose estimation is done. I see that it uses a bag-of-word method for loop detection, but how are current features ...
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0answers
40 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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0answers
19 views

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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0answers
354 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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0answers
103 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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1answer
555 views

Mobile robot pose estimation

I want to plot the path of a vehicle via the estimation of egomotion based on essential matrix. Everything was fine with openCV and the following function. ...
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0answers
86 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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1answer
144 views

What sensors can track small objects (5 cm - 25 cm) in bright sunlight? [closed]

ToF (time-of-flight) cameras seem susceptible to bright outdoor conditions. Are there any sensors made for bright outdoor conditions and could be embeddable in a robot that could detect and/or track ...
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0answers
81 views

choice for camera sensor to be used with LiDAR [closed]

I am doing research on autonomous car and looking for a sensor to be used along with LiDAR laser scanner. Ladybug could be a very good option but the cost!! too expensive. Could you please suggest me ...
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2answers
352 views

Robotic cell simulation software, PLC [closed]

I need to simulate robotic cell where cartesian robot trims a PCB arriving on conveyor, picks it up with vacuum cup and and places in another device. After receiving signal from device the robot would ...
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0answers
594 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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3answers
185 views

Why do robots need rangefinders while animals don't?

Will vision based system eventually prevail rangefinders based systems given that the most successful autonomous agents in the world like animals use primarily visions to navigate?
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3answers
74 views

Is it a bad-design decision to implement high number of moving parts in an automation-robot?

I'm currently designing an autonomous robotic system to manipulate clothes using computer vision and complex moving hardware. My current design incorporates quite a number of moving parts. My biggest ...
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4answers
4k views

Computer vision with single camera vs. distance sensors for obstacle detection [closed]

I am going to start a new project consisting in implementing an autonomous driving RC car. The car as it is now, has a camera installed on each side of the car, i.e. 4 cameras in total. They are ...
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1answer
256 views

Kalman filter for vision based pose estimation: 'good' measurements not improving system covariance

I am starting off with a very simple Kalman filter for vision based pose estimation (PnP algorithm). The filter is inspired by the constant velocity model in this OpenCV tutorial, but I am ignoring ...
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1answer
386 views

Are stereo camera calibration data standardized?

Is there a standard format of how stereo calibration data (various matrices, usually saved in XML) are stored? Can I load calibration data generated say from a OpenCV script in C to another OpenCV ...
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3answers
2k views

System for determining occupied seats in an auditorium [closed]

I need an app that can do live monitoring of whether each seat in an auditorium is occupied, so visitors can load the app and see where to sit. The auditorium has a relatively flat ceiling 4m ...
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1answer
22 views

Can you plug a CMOS camera (like the iPhone 8 back camera) into an mPCIe in a laptop?

I read that 12 megapixel iPhone cameras don’t record video in 12 megapixels because the processors are not able to keep up. It seems though, that if I could plug the CMOS sensor to the CPU of a laptop,...
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1answer
55 views

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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2answers
44 views

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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2answers
63 views

For pose estimation, what is the typical range of the rotation values that are estimated? Is it from -180 to 180 degrees?

I am currently working with the Rutgers APC 2015 data set for pose estimation, and see that the pose estimates, specifically the rotation estimates, have seemingly been rescaled to range between -1 ...
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1answer
1k views

How many AR markers should I use to get the object pose?

I'd like to get the object pose based on the attached AR marker to the object. I believe I only need one tag to get the 6D pose. However, I sometimes see more than one AR markers are used in the ...
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3answers
508 views

Real time operating system for robotics vision

I have robot vision system which consists of conveyor with encoder, two cameras (gigabit eth and usb) and simple illuminator. I need to trigger cameras and illuminator when encoder reaches position ...
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1answer
33 views

Depth camera pixel values to 3D coordinates

I have a robotic arm 6-DOF and an Intel RealSense depth camera. I want to go from pixel values to 3D world coordinates, is it possible with eye-in-hand calibration? If yes can you guide me on how to ...
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2answers
250 views

What are the purpose of pre-trained weights for YOLO object detector?

Dear Research Community, I am new to object detection research and currently working on a project which will detect people using YOLO from a top-down camera image. While looking through tutorials for ...
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1answer
251 views

Is easier to detect a large or a small marker? (Aruco / Apriltags)

I need to detect Aruco/Apriltags markers and perform pose estimation, but I've no particular constraint on their physical size. I'm not talking about the number of square (e.g. 4x4, 6x6, etc.), but of ...
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2answers
190 views

Triangulation: Ceres solver minimizes only the last residual block

I have been attempting to estimate a bunch of 3d coordinates viewed via a multi-view setup with known poses, I have the code running, but the output of ceres seems baffling. There are 7 image frames/...
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1answer
43 views

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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1answer
44 views

Dual constraint non-linear optimization for SLAM

I am trying to achieve a nonlinear optimization for SLAM on a function that contains two different constraints, like this : $$ T_{opt} = \underset{T}{\arg\min} \sum_i(\left\lVert T.X_i - x_i \right\...
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1answer
512 views

What is the relation between FOV, Focal Length and Sensor size in a Pin hole Camera Model?

I aim to recreate the camera parameters of my camera in the Unity rendering system, which has the following variables: 1) I tweaked the focal length and saw that the Field of View is changing (...
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1answer
81 views

How to tringulate many projections of a point to optimal postion?

Suppose we have many images for the same scene (with known poses already,using for ex: a GPS ), and the same feature appear in more than 2 images . How to use all the available info to compute as ...
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1answer
152 views

Perspective N point solution: Position drifting linearly with rotation angles?

I am using a PNP algorithm to compute the rotation and translation of a camera given pre-mapped 3D points, and their corresponding projections on the 2D plane. The algorithm I am using is the one ...
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1answer
247 views

Methods for odometry/IMU/Gyro free lidar pointcloud registration for pose estimation

I am currently trying to register a pointcloud in time to find my change in position and heading at each timestep (High speed application). So this is essentially an implementation of SLAM. I am ...
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2answers
177 views

Depth sensing for a pick-and-place robot

I am supposed to design a pick-and-place robot. I have a prismatic joint to go down to a particular depth to pick an object which is located in 2D using computer vision. What is the recommended way to ...
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2answers
828 views

Scan an Auditorium, Count People, and Display Open Seats [closed]

I'm looking for any recommended approaches to be able to digitally process a room full people, like an auditorium or a movie theater and output the following information: How many people are in the ...
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1answer
104 views

Road Detection When the Robot is Off-Road

I'm trying to make a lightweight method of outdoor road following for a small ground robot. In nearly all road detection work that I've seen, they all assume that the robot is already on the road, ...
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1answer
59 views

Is it possible to detect road surface or navigation area using LRF data or other laser data in a Park?

I would like to detect road surface in a park. In the park, only small grass are covered with the both side of the road. That means there is road and the both side of the road are covered by small ...
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1answer
68 views

Compound vision system or Megapixel camera reduction

Are any commercially available compound vision sensors available? Not a simple 8 sensor system using photo-diodes but a genuine sensor that can provide a >32x32 compound matrix. Would some form of ...
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1answer
691 views

tracking robot in a room

I'm trying to track a simple robot (e.g. arduino, raspberry pi, even toys) in a room using fixed location kinect sensor(s) and cameras at different parts of the room. How might one usually use to do ...
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1answer
316 views

kinect - development kit to aid obstacle-avoiding robot?

Some friends and I are interested in working on a robot. I know little to nothing about robotics, but do have a lot of experience with programming. Before we start, I am hoping that I can find some ...
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1answer
185 views

Tried Normal Distributions Transform with my own files (in correct PCD format) and it throws errors, why?

http://pointclouds.org/documentation/tutorials/normal_distributions_transform.php#normal-distributions-transform I've used this program with the sample PCD's given and it came out correctly. This was ...
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1answer
40 views

Autonomous harvesting robots. What are model possible components and interactions for the entire system? [closed]

I found a video which talk about best autonomous robots that use IA technology to harvest crops. The video is very interesting because, the “ecosystem” of each robot varies a lot from company to ...
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0answers
25 views

Is there any RAPID instruction to save image as variable in YuMi integrated vision without using RobotStudio?

I want to perceive the images from the cameras embedded in YuMi IRB 14000 arms and store them as videos, in Ubuntu without using ABB RobotStudio. is there any way to do that? if yes how can I do that ...
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2answers
36 views

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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0answers
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)...