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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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Position vs Image based visual servoing?

Can anyone explain Image based visual servoing for robotic arm through example? I can understand Position based based visual servoing like this, .... there is an object and estimating it 6D Pose ...
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20 views

RGBD Camera Eye in Hand Calibration

Hello I am new to robotics. So far I have a basic understanding of the camera calibration. One would need rotation and transformation matrices to convert a point from camera coordinate system to robot/...
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40 views

vision guided robotic arm always required 6d pose of object? [closed]

I have an object like attached in image. It is hanging vertical (its position may change but static object) and I want to grasp it using 6DOF Robotic arm. I am Using camera to detect object. I am ...
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1answer
20 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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1answer
47 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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49 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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13 views

Ready to use camera calibration in linux

I am looking for a ready-to-use implementation of "opencv" camera calibration in Ubuntu. I have mine but the code was implemented for the windows. I would like to convert it but simply the deadline is ...
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1answer
57 views

How can I preserve a high framerate while using at least 1280x720 resolution on 2 USB cameras on the same computer?

To expand on this, I have a down-facing camera using the whycon ROS node on Ubuntu 16.04 Kinetic on a quad-core computer with 640x480@60fps MJPG video. I'm also using the ...
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How can I import openmv camera feed in MATLAB

I am planning to use openmv camera with wifi shield for my project. I want to import the video feed to MATLAB for further processing. As per my preliminary search it is extremely difficult and ...
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32 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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21 views

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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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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1answer
54 views

Setting up a Structured Light Stereo system

I am trying to get started with a stereo experiment and wanted to know the mistakes I might have made during the experiment. The goal is to calculate the depth map of an object using one light ...
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2answers
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Hand eye calibration of robot arm using a 2D camera and marker of known size

If my understanding is correct, one flavor of hand eye calibration requires the following pairs of data for different robot arm positions: The transform from the robot base to the robot hand. The ...
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1answer
19 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
170 views

IMU and Camera Synchronization

I would like to synchronize my IMU and Camera sensors for my real-time visual-inertial SLAM algorithm in ROS. I am streaming video at 30 Hz from an android phone through IP address. IMU, however, has ...
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Question about Lens distortion

Suppose I have a 240x180 camera with the following distortion co-efficients, $$k_1 = -0.138592767408$$ $$k_2=0.0933736664192$$ $$k_3=0.0$$ $$p_1=k_4=-0.000335586987532$$ $$p_2=k_5=0.000173720158228$$ ...
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23 views

Accuracy of monocular visual-inertial odometry

I am currently considering to use monocular visual-inertial odometry to localize a smartphone relative to a known object. Now, what I would like to understand, is what kind of accuracy I can expect ...
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1answer
38 views

Trigger two usb cameras at the same time

I'm studyng stereo cameras, and I want to build one. I searched a lot in internet, and the opinions are quite different about this topic. Basically, my question is: Can I synchronize two usb ...
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88 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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1answer
76 views

Robot localization using sensor fusion (How to model the Extended Kalman Filter)?

I am new to the robotics field and sensor fusion as well. I am trying to localize my robot using the data from my camera and the odometery through extended Kalman filter. I have the data offline, I ...
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2answers
38 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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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
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what's the difference among rgb-d camera, depth camera, 3d camera, and stereo camera?

I'm very new in this field so my question may be very stupid. I apologize for this at first. I'm trying to use a proper camera to run a SLAM algorithm. As suggested by some people, stereo camera may ...
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1answer
74 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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2answers
48 views

What materials can I put in front of a RGB camera and LED IR lights to hide the sensors as much as possible?

I'm making a consumer camera prototype and want to make the front look as clean as possible. Right now I use a completely transparent material and the camera and the IR Lights (with their red hue) are ...
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1answer
75 views

Can you find object distance using camera pose

I have bounding boxes detected in RGB images, but no information about the camera's intrinsic properties. Using deep learning (preferably) can I find the distance to the object from the camera in real ...
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126 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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1answer
30 views

Finding the manufacturer for a sensor

We're building a smart camera and one of our competitors is using a depth sensor we're interested in using. If we open up the product, is it common to be able to see manufacturer information for ...
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1answer
23 views

Depth cameras with varying illuminations

We realized that depth cameras (IFM) tend to create a lot of noise when exposed in areas with direct sunlight. Are there any approaches to deal with illuminations? Eliminating pixels for instance?
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1answer
357 views

Image coordinate to robot coordinate

I am working with a Nao robot. One if the things I want to do is the following: Take an image of geometrical objects in front of the Nao (done) Extract features from the objects in the image, such as ...
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2answers
100 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
158 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
31 views

Determining time difference of image capturing in multi camera setup

it is widely discussed in this forum, how to sync multiple cameras (e.g. best done via hardware trigger). Now I'd like to know how to actually determine the time delay between two image streams and ...
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1answer
393 views

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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1answer
292 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 ...
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1answer
41 views

My Plug Says It's USB, I can't Identify

I ordered this cool little USB endoscope camera, but the cord does not look like any type of USB I have ever seen. I would eventually like to make this act like a webcam, so does that make a ...
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0answers
26 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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2k views

normalized point coordinates in undistortPoints function

In undistortPoints function from OpenCV, the documentations says that http://docs.opencv.org/2.4/modules/imgproc/doc/geometric_transformations.html#undistortpoints where undistort() is an ...
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1answer
526 views

Image registration with ground plane for surround view

I am currently working on a project which which involves surround view. I have 4 fish eye cameras and are fixed at 4 sides of a car.The fish eye cameras are corrected for radial distortion. After ...
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1answer
146 views

Live Streaming video via Arduino with limited space [closed]

I am currently undertaking a competition called CanSat, in which you build a satellite in the form of a standard soda can. It will in turn then be launched 30 meters, 100 meters and then ...
2
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1answer
406 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
47 views

Correct calibration parameters of stereo system due to vibrations

In stereo vision, the camera is calibrated using the popular chessboard before use. During the course of use, the camera maybe be subject to environmental factors such as vibrations.This may cause ...
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2answers
156 views

I am making a Ping pong-playing robot using two cameras to trace the ball (3D vision),what is the minimum Frame rate of the cameras?

I am making a Ping pong-playing robot, like the one in this video, and i am intending to use two cameras to trace the ball in 3D space. Supposing that the robot is playing against a beginner player, ...
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1answer
220 views

setup requirement of stereo camera

In the stereo camera system, two cameras are needed and should be mounted side by side. I see someone just glues two cameras to a wooden board. However one mobile phone manufacture claimed that the ...
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1answer
260 views

Effect of camera misalignment errors in dual cameras

In the camera module assembly process, parameters of camera modules vary due to manufacturing tolerance. Camera calibration is performed to obtain actual parameters. In the paper Effects of camera ...
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1answer
46 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
825 views

Scale problem with monocular visual odometry

Is monocular visual odometry able to estimate relative scale? Say I have a sequence of 10 images that are taken on a single track each 1 m after the previous. Can some mono odometry method distinguish ...
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2answers
349 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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2answers
3k views

Camera selection for long range stereo vision system (up to 100 meters)

I want to implement a real-time stereo vision system for long range (up to 100m) depth estimation. I know that there are some general considerations as described in this SOV post. I have seen some ...