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Qu Cao

Last seen: 7 days ago Active since 2016

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Answered
Difficulties in obtaining good results with the ORB-SLAM2 algorithm in MATLAB.
Thank you for posting the question. In general, tuning the hyperparameters for a visual SLAM system can be hard and requires a...

2 months ago | 1

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Answered
vSLAM: vSLAM algorithm is very sensitive to hyperparameters Issue?
You find the nature of the SLAM problem. Yes, the visual SLAM system is sensitive to hyperprameters which usually need to be tun...

2 months ago | 0

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Answered
How to construct stereoParameters with intrinsic and extrinsic matrix?
poseCamera2 essentially transforms camera 2 to camer 1. If you have “the transaltion and rotation from camera1 to camera 2”, (le...

2 months ago | 1

Answered
Object 3D world coordinates from multiple images
You will need a stereo camera to give you the actual dimension of 3-D objects. Alternatively,if you know the size of an object...

3 months ago | 0

Answered
creating a bag of features for new image set for monocular SLAM
The bag-of-features data may not work for the KITTI dataset because it was trained using a small amount of image data. You may w...

3 months ago | 1

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Answered
The Premultiply Convention in Geometric Transformations does not support C/C++ code generation?
Thank you for reporting this. There is a bug in the documentation. All the geometric transformation objects with the premultiply...

3 months ago | 0

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Answered
How to use reconstructScene with a disparity map from file, without calling rectifyStereoImages ?
You can use the reprojectionMatrix output from rectifyStereoImages to do the reconstruction. Otherwise, you need to save the ste...

5 months ago | 0

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Answered
Match the coordinate systems of "triangulate" and "reconstructScene" with "disparitySGM"
The point cloud generated from reconstructScene is in the rectified camera 1 coordinate. Starting in R2022a, you can use the ad...

5 months ago | 0

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Answered
MATLAB Simulate 3D Camera: why is there no focal length (world units) attribute in the sensor model?
Please take a look at this page: https://www.mathworks.com/help/vision/ug/camera-calibration.html#bu0ni74 If you know the size...

8 months ago | 0

Answered
How to port SLAM algorithm to embedded platform?
Unfortunately, as of R2022a the visual SLAM pipeline doesn't support code generation yet. We're actively working on this suppopr...

8 months ago | 1

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Answered
how to get the relative camera pose to another camera pose?
Note that the geometric transformation convention used in the Computer Vision Toolbox (CVT) is different from the one used in th...

9 months ago | 1

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Answered
How to get 3D world coordinates from 2D image coordinates?
You should use the rectified stereo images. The disparityMap computed from disparitySGM should have the same size as your stereo...

11 months ago | 0

Answered
Creating a depth map from the disparity map function
You can use reconstructScene for your workflow.

11 months ago | 0

Answered
Unable to use functions from the Computer Vision Toolbox in Simulink MATLAB function block
A workaround is to declare the function as an extrinsic function so that it will be essentially executed in MATLAB: https://www...

12 months ago | 0

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Answered
how to get texture extraction using LBP features in MATLAB?
You can use the extractLBPFeatures function.

1 year ago | 0

Answered
About error of helperVisualizeMotionAndStructureStereo
In helperVisualizeMotionAndStructureStereo.m, please note the following code in retrievePlottedData which discards xyzPoints out...

1 year ago | 1

Answered
About SLAM initial Pose data
The initial pose data is provided by the dataset. It's used to convert the 3-D reconstruction into the world coordinate system. ...

1 year ago | 0

Answered
About "slam" on my camera device
The example shows how to run stereo visual SLAM using recorded data. It doesn't support "online" visual SLAM yet, meaning that y...

1 year ago | 0

Answered
Is Unreal Engine of the Automated Driving Toolbox available on Ubuntu?
As of R2021a, only Windows is supported. See Unreal Engine Simulation Environment Requirements and Limitations.

1 year ago | 1

Answered
why we use Unreal engine when there is a 3D visualization available in Automated driving toolbox?
It's not just used for visualization. With Unreal, you can configure prebuilt scenes, place and move vehicles within the scene, ...

1 year ago | 0

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Answered
About running a stereo camera calibrator
In general, you can use any type of stereo camera and calibrate its intrinsic parameters using the Stereo Camera Calibrator. You...

1 year ago | 0

Answered
How to obtain optimal path between start and goal pose using pathPlannerRRT() and plan()?
Please set the random seed at the beginning to get consistent results across different runs: https://www.mathworks.com/help/mat...

1 year ago | 0

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Answered
Does vehicleCostmap this type of map only support pathPlannerRRT object to plan a path? Can I use another algorithm to plan a path?
You can create an occupancyMap object from a vehicleCostmap object using the following syntax: map = occupancyMap(p,resolution)...

1 year ago | 0

Answered
Defining a ROI for feature extraction rather than rectangle
Unfortunately, rectangle is the only type of ROI supported. As a workaround, you can define multiple ROIs in your image to cover...

1 year ago | 1

Answered
Monocular Visual Simultaneous Localization and Mapping Error: Dot indexing is not supported for variables of this type.
The example has been updated over the past few releases. For 20b version, please check the following documentation: https://www...

1 year ago | 0

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Answered
How can I store the feature descriptors for all 3D points found in Structure from Motion?
You can use imageviewset to store the feature points associated with each view and the connections between the views. You can al...

2 years ago | 0

Answered
How to use "triangulateMultiview" to reconstruct the same world coordinate point under multiple different views?
triangulateMultiview requires both camera poses and intrinsic parameters inputs to compute the 3-D world positions corresponding...

2 years ago | 0

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Answered
imageviewset() not returning an imageviewset object
imageviewset is introduced in R2020a. If you are not able to upgrade to 20a, you can use viewSet as a workaround.

2 years ago | 0

Answered
How to ensure that the number of matches between 2 images is equal to the number given?
You can set 'MatchThreshold' to 100 and 'MaxRatio' to 1.

2 years ago | 0

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Answered
Undefined function 'estimateGeomerticTransform' for input arguments of type 'SURFPoints'.
There is a typo in your code, estimateGeomerticTransform should be estimateGeometricTransform.

2 years ago | 0

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