All Questions
Tagged with opencv computer-vision
23 questions
0
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16
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Estimate 3D location of a tracked point with Known Camera parameters and Distance
I want to estimate the 3D point of X̅₂,
X̅₂ = [ X₂ Y₂ Z₂ ],
by using known variables:
X̅₁ is at world origin,
camera intrinsics K,
camera extrinsics w.r.t. X̅₁, namely [R₁ ∣ t₁],
...
- 1
0
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0
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14
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Calculate disparity for matching feature points
If I have matched a pair of feature points, could I calculate its disparity by simply subtract the u coordinates(uL - uR)? And could use this disparity to calculate the depth for this 3d point?
...
- 3
0
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1
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154
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Calibration of camera using ROS, without camera info
As part of a college project, I need to communicate with a TM5-700 robotic arm developed by Omron, and implement, for now, a pick and place pipeline. For that, I am required to access the camera ...
1
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2
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130
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Detecting door blockage using computer vision
I want to detect door blockage on a camera. Basically if the exit door is blocked by an object, it detects it as an anomaly. How can we do it? Is it possible to do it using OpenCV?
Remember, it doesn’...
- 111
1
vote
2
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872
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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/...
1
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0
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101
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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 ...
- 161
1
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1
answer
88
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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 ...
- 123
2
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1
answer
204
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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 ...
2
votes
1
answer
689
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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 ...
- 21
4
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1
answer
9k
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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 ...
- 235
3
votes
1
answer
1k
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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 ...
- 151
1
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2
answers
1k
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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 ...
- 111
0
votes
1
answer
593
views
Tracking a ball returning its x,y,z coordinates [closed]
I'm a Mechatronics Student Engineer, and still new with the computer vision field and am now working on a project that needs to Tracks a small ball and need to determine it's (x,y,z).
1st) Kinect was ...
2
votes
1
answer
643
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.
...
- 125
2
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0
answers
333
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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 ...
- 125
0
votes
1
answer
5k
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 ...
- 273
6
votes
1
answer
3k
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Which is the best visual fiducial marker (2D barcode)?
Which is the best visual fiducial marker (2D barcode) for detection and robust and accurate pose estimation?
Im not looking for a fiducial marker which can store lot of information. The main goal is ...
- 417
3
votes
1
answer
3k
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 ...
- 31
0
votes
1
answer
191
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Google's 'Tango' - How it works and what's special about the hardware?
I'm looking for a good breakdown and explanation of Google's 'Tango' AR platform. Specifically how the hardware works together to generate depth maps and the SDK's use of it.
I know the hardware ...
- 153
5
votes
1
answer
943
views
How to check lane departure in OpenCV?
I'm using OpenCV 3 in Python 2.7 on a Raspberry Pi 3. My project's aim is to build an autonomous lane departing robot that can detect the two lanes on its sides and continuously correct itself to ...
- 51
0
votes
1
answer
488
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detect post-it from an image of a visual management Board [closed]
'm trying to detect all the post-it in an image and get them into an arrayList. I tried many alternatives (removing backgroud -> detecting contours, haar Cascade
classifier, detecting rectangular ...
- 1
5
votes
2
answers
2k
views
Transforming Point Cloud to get Top Down Image [closed]
My task:
I have a task where I am asked to track parcels(carton boxes) of different dimensions moving on a conveyor. I am using Asus Xtion pro camera mounted on top of a conveyor in any inclined ...
- 151
2
votes
1
answer
1k
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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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