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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7k views

Determine the relative camera pose given two RGB camera frames in openCV-python

I would like to determine the relative camera pose given two RGB camera frames. I assume there's overlap in field of view between the two cameras, what I am looking for ultimately is the rotation and ...
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1answer
853 views

OpenCV get topdown view of planar pattern by using intrinsic and extrinsic from cameraCalibrate

Originally I have a image with a perfect circle grid, denoted as A I add some lens distortion and perspective transformation to it, and it becomes B In camera calibration, A would be my destination ...
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1answer
94 views

3D scanner from Phone Camera

123D software can construct a 3D model from photos taken from your phone. It doesn't process the photos in your phone. Instead, it sends them to the cloud to create 3d model. How can i construct a 3d ...
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1answer
516 views

Robot Navigation Feedback using Image Processing

In my project, I've successfully analyzed the arena and have detected the obstacles using an overhead webcam. I also have computed the shortest path. The path data is transmitted to the robot via ...
3
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1answer
180 views

Stereo camera baseline not needed for calibration?

I am doing stereo camera calibration as described in this blog post. I wonder I do not need to input camera baseline for the calibration. The fact probably goes back to some very basic mathematics of ...
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2answers
949 views

Connect sensors to beaglebone/arduino in a complex robot

I'm building the biggest robot I've ever done. The hardware I have so far is as follows: HCR-Platform from DFRobot as a base x2 12V 146Rpm DC motor with two phase hall encoder x7 Sharp 2Y0A21 IR ...
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1answer
231 views

Short range stereo vision

I am designing a stereo vision system for short depth range (15 cm to 35 cm) and I have some problems about baseline, focal length and depth range. My application is to scan an animal tissue (meat, ...
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2answers
322 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 ...
3
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1answer
526 views

How to eliminate motion blur with realtime performance

I have a robotic system to develop, in first phase of the project I need to track an object. So I placed a geometrical marker on the object to estimate it's pose (rotation, translation). It all works ...
3
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1answer
889 views

Correct Fish eye camera radial distortion and blurry stretch at the image edges

There are a lot of questions regarding this topic, but I am trying to get a more clear picture from these questions. I am trying to calibrate a fish eye camera and I am using OpenCV ...
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1answer
122 views

How to estimate the position of multiple static ground targets captured from a down facing camera?

An aerial vehicle captures images of the ground using its down facing camera. From the images, multiple targets are converted from their pixel position to the camera reference frame using the pinhole ...
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1answer
669 views

Suggestion for a camera [closed]

Are there good low cost cameras that are frequently used in robotics? I am assuming there are cameras that are good fit for robotics ... Works well with OpenCV PC Windows support - USB2/USB3 (GigE, ...
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171 views

Non-Vision Based Target Tracking

I am building 4-wheeled, knee-high robot with music and speakers on top that will follow a target person as the target moves around. I would like some help with the setup for tracking the target. The ...
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1answer
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How to obtain stereo correspondences and what exactly is a disparity map?

I am currently reading into the topic of stereo vision, using the book of Hartley&Zimmerman alongside some papers, as I am trying to develop an algorithm capable of creating elevation maps from ...
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1answer
316 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 ...
3
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1answer
871 views

Marginalization in Graph SLAM [duplicate]

I have several questions about the process of marginalization in SLAM algorithms: 0 - What are the mathematic intuition behind marginalization process 1 - I know marginalization of states or points ...
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319 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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0answers
810 views

Alternatives to Primesense depth cameras? [closed]

I'm looking for low-cost depth cameras (less than 1000 USD) with a range of more than 3 meters. Currently, I have found only SoftKinetic DS-311 that meets these requirements. Here are some other ...
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3answers
243 views

What the name of this kind of computer vision?

Whats the name of the technique used to read symbols with computer vision? Like the one used for this wood cutter: I want to use something like this to measure distance from the camera to a piece of ...
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1answer
153 views

Robotic Hand Grasp Planning - How do I find the initial contact point for each finger when grasping an object?

I am trying to design a robotic hand that is able to adaptively grasp unfamiliar objects. I am initially thinking that using OpenCV for pose estimation might make doing so easier. Assuming that I am ...
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2answers
1k views

Why do we need a marginalization in Bundle Adjustment?

A common practice in Bundle Adjustment is to reduce the state dimension by marginalizing structure or pose states to improve the optimization speed. In case 3d points(structure) $\textbf{p}_i$ are ...
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2answers
150 views

Smart camera image processing on embedded GPU vs. in the cloud

I'm working on a smart camera that does key point prediction (predicting locations of wrists, elbow, shoulder, ears, eyes, nose, etc.) for gesture recognition. Right now, the neural net is running on ...
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1answer
1k views

Machine Vision vs Computer Vision?

I'm trying to understand the core differences between the two topics. Is one simply a newer term? Connotations of automobile vs automation? Something with a screen vs without? I've only ever heard ...
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4k views

Using an RGB + Depth Camera to locate X,Y,Z coordinates of a ball

I've recently been trying to use Gazebo to do some modelling for a couple tasks. I have a robot that's effectively able to locate a ball and get x,y coordinates in terms of pixels using a simple RGB ...
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1answer
69 views

“Ambiguous up to scale” , Explanation required

I am reading "Computer Vision: Models, Learning, and Inference" in which author writes at several points (like on page 428-429) that although matrix A seems to have 'n' degree of freedom but since it ...
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2answers
712 views

Find Centre Of Circle, when robot can “see” a partial arc

I originally asked this here but I am struggling to take the concepts, particularly "Circumcenter", discussed there and apply it in my context. So here it is in my context... I have a small robot ...
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2answers
76 views

Image processing in bright lights

We are working on a project which requires us to detect and hit a ball. We are trying to accomplish the task by detecting the position of ball by processing the input from a camera. The problem is ...
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2answers
91 views

Detect road surface in a traffic scene point cloud

I want to analyze a traffic scene. My source data is a point cloud like this one (see images at the bottom of that post). I want to be able to detect objects that are on the road (cars, cyclists etc.)....
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1answer
16k views

How can I interface my CMOS camera module to an Arduino? [closed]

I am totally new to the camera interface and usage in an Embedded project, and would like to use a CMOS vision sensor like this.This project further will be used to power a small robot with on-board ...
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2answers
484 views

How does structured light improve accuracy in stereo vision?

In my understanding, in order to improve accuracy for the estimation of depth with a stereo vision camera, patterns of light are projected into the scene, because the resulting texture makes it easier ...
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2answers
397 views

Using Standard Digital camera for Computer Vision

For a University project I have to use computer vision to detect small drones within 40 feet. I know there exists a pixycam for this purpose, but I was not happy with it, when I used it for CV. I ...
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1answer
131 views

Once matching features are computed between a stereo pair, how can they be tracked?

I am currently working on a SLAM-like application using a variable baseline stereo rig. Assuming I'm trying to perform visual SLAM using a stereo camera, my initialization routine would involve ...
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1answer
1k views

Stereo Vision Using Compute Module: Pi camera synchronization

Good day, I am currently working on an obstacle avoiding UAV using stereo vision to obtain depth maps. I noticed that the quadcopter would sometimes not steer to the correct direction. I am using ...
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1answer
2k views

Perspective n Point - RPnP algorithm

I need to caculate the pose of a camera using an image of an artificial landmkark. For this porpouse I am trying to use the Perspective n Point approach so I can calculate it using the intrinsic ...
2
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1answer
371 views

Autonomous Indoor Positioning System Robot based on CV approach

I have some questions regarding an IPS autonomous robot system, Configuration: Mounting a camera to the ceiling of a room Assume the room is a cube of 5mx5mx5m (LxWxH) Assume the camera is ...
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3answers
136 views

Vision-based Position Estimation for a quadrotor

As a subtask inside a main project I need to compute the position (x,y,z) of a quadrotor using an homography. To do this I will use a camera (attached to the quadrotor) pointing down to an ...
2
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2answers
566 views

image size vs image resolution

I read somewhere that in the case of photoshop for example, the size refers to the number of pixels an image contains, but resolution involves the pixel's size, I don't know whether this definition ...
2
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1answer
41 views

Sensors to detect targets in low visibility environment

I want to know what type of sensor hardware I need to allow detection of moving targets (20mm - 200mm size range) in heavily murky water, where visibility range of typical camera can be limited to 0.5 ...
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2answers
136 views

How to handle landmarks in Bundle Adjustment?

At the moment I try to understand Bundle Adjustment on a level to be able to implement it on my own. The major point I'm still confused at is the management of the landmarks. So, let's think of a few ...
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1answer
153 views

Fusing Multiple Lidars Into 1 Point Cloud

I have a car with 8 lidars, each with a field of view of 60 degrees. My car looks like this How can I merge all the lidar readings into 1 point cloud?
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1answer
83 views

Efficient sphere surface area search

As shown in the figure, there are objects of arbitrary shapes placed on the surface of the sphere at arbitrary locations. The problem is to search the surface to locate these objects in most efficient ...
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1answer
47 views

How to perform active search in point feature based monoSLAM?

I am modifying an implementation of SLAM with single camera, MonoSLAM [1]. Instead of image patches, I want to use features points (ORB) to track landmarks. MonoSLAM uses a EKF framework. So for ...
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1answer
112 views

Fixing the first node in Graph-based SLAM

The first node in the graph SLAM should be fixed. The famous "a tutorial on graph based slam" paper is showing that we can fix a node by adding identity matrix. Why adding identity to the Hessian of ...
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1answer
215 views

How to build a robotics ontology?

According to some papers about robotics soccer Ontology Driven Development of Domain-Specific Languages, 2000 and Domain knowledge for surveillance applications, 2007, i need an ontology for ...
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1answer
2k views

Converting Image Coordinates to (x, y) Position for Robotic Arm

I have a Robotic Arm with a camera mounted above it looking down at a slight angle. Assuming I know the height of the camera, the angle of tilt and the small distance from the center of the robot ...
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1answer
53 views

Is there a better way to deal with untextured regions in stereo matching

Texture is very helpful for stereo matching. However in real environment, untextured areas always exit. Consistent semi-global matching is proposed to deal with untextured regions. I start to read the ...
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1answer
175 views

Object Detection and Pose Estimaion

I am working on a robotics project for fun and can't really wrap my head around a solution to my perception problem. Setup: My robot will have a stereo vision setup and will have to detect certain ...
2
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1answer
466 views

How does one calculate distance and angle using a target with known measurements?

The target is in the shape of a U where the horizontal segment is 20 inches, and the two vertical segments are 14 inches. We are using a camera to image the target, and then using vision processing to ...
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1answer
388 views

Maximum angle between the camera pose to correctly estimate homography

I want to capture two views of same scene. The scene consists of a set of objects kept on a table. From the two views, I wish to calculate homography for image matching. I want to know what is the ...
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1answer
226 views

Workable low-resolution object/target recognition pattern and library?

I've spent quite some time researching this, but most of my Google search results have turned up academic research papers that are interesting but not very practical. I'm working on a target/pattern ...