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Qu Cao


Last seen: Today

MathWorks

31 total contributions since 2016

I'm an Automated Driving and Mapping Engineer at MathWorks and a Mechanical Engineer by education.

DISCLAIMER: Any advice or opinions posted here are my own, and in no way reflect that of MathWorks.

Qu Cao's Badges

  • Knowledgeable Level 2
  • Revival Level 2
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Answered
rectangle instead of square for camera calibration
Unfortunately, this function does not support rectangle patterns.

13 days ago | 0

Answered
How to calculate fisheye intrinsics?
You can use undistortFisheyeImage function to produce a "virtual perspective" camera intrinsics, which is the format you need. S...

2 months ago | 1

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Answered
How can I find a diameter of cylindrical 3D point cloud in MATLAB?
https://www.mathworks.com/help/vision/ref/pcfitcylinder.html

2 months ago | 0

Answered
Function estimateWorldCameraPose() or extrinsics() for fisheyeParameters is missing. Is it possible to change these functions for fisheye?
fisheyeIntrinsics can't be used directly. Instead, you can use undistortFisheyeImage function to produce both undistorted image ...

2 months ago | 2

| accepted

Answered
Unit of worldpoints returned by triangulate function
The unit is determined by the input stereoParams. The default world unit is mm: https://www.mathworks.com/help/vision/ref/stere...

7 months ago | 1

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Answered
How to Transform of coordinate of actors from vehicle coordinate to world coordinate or refference coordinate system (ADAS toolbox) ...?
The following documenation page explains the vehicle coordinate system and the world coordinate system: https://www.mathworks.c...

7 months ago | 0

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Answered
3D Vision Toolbox - DisparityRange - what limits the range to 128 and why?
This is due to the implementation that utilizes parallel programming on multi-core processors. The following post might be hel...

7 months ago | 0

Answered
How to find union of two SURFPOINTS variables?
surf3 = union(surf1, surf2, 'rows');

9 months ago | 0

Answered
Create a cameraParameters object with more than one Intristic Matrix?
Since R2019b, you can use an array of cameraIntrinsics objects to represent the intrinsic parameters of a bunch of different cam...

9 months ago | 0

Answered
How can i compute depth maps from disparities maps of stereo pairs captured with a calibrated camera ?
You can use disparityBM or disparitySGM to compute a depth map.

9 months ago | 0

Answered
Camera looking down the negative Z-Axis
Hi Alex, In Computer Vision Toolbox we use the y-down/z-forward camera coordinate systems: https://www.mathworks.com/help/visi...

9 months ago | 0

Answered
Camera Pose Estimation from Non-calibrated camera images
Unfortunately, currently all the functions used in the Structure-from-Motion workflow require the camera to be calibrated. You c...

11 months ago | 0

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How to limit ORB features?
Hi Helia, the selectStrongest function picks the points based on the Metric values: https://www.mathworks.com/help/vision/ref/o...

11 months ago | 1

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Answered
What is the reference point for the orientation and location arguments of addView and addConnection functions in CV Toolbox?
In both functions, it means relative to the previous view, not the very first view.

1 year ago | 0

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Answered
Camera Calibrator Parameters and estimation errors (How to use post calibration)
Once you get the camera parameters from the App, you can use undistortImage to undistort new images if they are captured by the ...

1 year ago | 0

Answered
Wrong Documentation for pointsToWorld?
You may want to use fisheyeIntrinsics in this case.

1 year ago | 0

Answered
shouldn't the reference frame replace the frames of the subsystem
Since the Reference Frame is attached to Solid 8 not the World Coordinate, the rotating axis will be one of the Solids 8's refer...

3 years ago | 0

Answered
glme can't deal with NaNs?
According to the error message, it seems that the error is not associated with NaN but the rank of the matrix X. You can chec...

4 years ago | 0

Answered
How to change a multi-variable matrix with different sliders?
It might be difficult to understand your workflow without a snapshot of the GUI you are designing. One suggestion to debug t...

4 years ago | 0

Answered
For loop inside functions in fsolve
I recommend you to provide more details about the equations you want to solve. You can also refer to the following documenta...

4 years ago | 0

Answered
Using intel Atom as xPC target
http://www.mathworks.com/matlabcentral/answers/102370-is-matlab-supported-on-intel-atom-processor

4 years ago | 0

Answered
Derive class from Simulink.ConfigComponent
After opening a model (any model), you can use the following code to get access to the Simulink.ConfigComponent of the model: ...

4 years ago | 0

Answered
Figures copied to Powerpoint cropped
MATLAB is officially not supported on dual-monitor systems. The following information might be helpful for you to resolve th...

4 years ago | 0

Answered
Is there more documentation on Stateflow messages for MATLAB 2016a?
The following examples should be able to provide you a better understanding of Stateflow messages: http://www.mathworks.com/h...

4 years ago | 0

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Answered
How can I read Fortran90 binary files in MATLAB?
You can try using 'fread' to read Fortran binary files into MATLAB. The following link should be useful for you: http://www.m...

4 years ago | 0

Answered
Least squares fit to multiple differently-sized data sets simultaneously
The data sets should have the same number of points. The 'xdata' and 'ydata' should be well defined vetors or matrices.

4 years ago | 0

Answered
Slow High Resolution video processing
The DeployableVideoPlayer object displays video frames. This player is capable of displaying high definition video at high frame...

4 years ago | 0

Answered
What type of multiple comparisons is used in multcompare?
Hi Eric, You can specify the type of comparison as documented at the following link: http://www.mathworks.com/help/stats/m...

4 years ago | 0

Answered
How do I use the Mantel Test to test correlation between two matrices?
I recommend you to contact the author of this function for support.

4 years ago | 0

Answered
Why can't I connect my Simscape circuit to a PS-Simulink converter -- only a dashed red line appears?
Hi, George, To view the voltage at a circuit node, you should use the Voltage Sensor block: <http://www.mathworks.com/help...

4 years ago | 0

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