# Tagged Questions

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19 views

### Determining the covariance of point clouds in real-time

So basically I have a set of multidimensional data that I need to determine the covariance of between dimensions in real-time. Each point that comes in is a vector. I have gotten the mean and variance ...
28 views

### Point cloud comparison

Let me preface this question with the fact that two hours ago I had no idea what a cloud point was. I do however have a solid mathematical background although geometry has never been my focus. I do ...
12 views

### Point cloud color blending after registration

I have succesfully registered two point clouds of the same scene obtained from different camera positions. Color values are different due to changes in light condition between both positions. I would ...
75 views

### Image distortion and alignment on 3D mesh / pointcloud

Currently I have a fairly accurate (50 µm) and large dataset from a 3D scanner and a set of high resolution pictures. Sadly the 3D scanner (a Nikon/Metris arm-based CMM that was hanging around the lab)...
34 views

### Processing line scanner data

I have a line scanner output that is scanning the geometry of a surface. Typically the output looks something like this: Where the x and y axis refers to the coordinate system in mm. (ignore the ...
120 views

### Can the Z-Transform be used to create smoothed 3D surfaces from point clouds?

According to Dr. Math the Z-transform can create closed-form solutions for 1D series defined by difference equations (e.g. the Fibonacci series). My 3D surface $z=LC(x,y)$ is defined by difference ...
41 views

### Why is the backprojection of the Middlesbury depth map “cone shaped”?

I wrote some come to backproject depth maps. Testing it with the Middlebury cone set, I get: First of all it has noise, which I shouldn't get from the ground truth, but more importantly it seems ...
103 views

### 3D point cloud to 2.5D graycale image (metric) [Halcon?]

I have a problem ragarding transferring a point cloud to a 2.5D metric grayscale image (gray value gives depth information). I start with a three channel image of 32bit floats with each pixel ...
280 views

### What exactly do we do in non-rigid registration?

I found many readings on Non rigid registration, also saw some videos but didn't find a clear explanation anywhere. What I understood is the following Rigid ...
2k views

### Calculating the volume of a triangular mesh?

I have an unorganized point cloud with a bunch of 3d points. I use a certain surface reconstruction method to obtain a triangle mesh of the underlying surface. The surface could be closed or not. Can ...
327 views

### How to: pixel packs in an image to representative point coordinates (x,y)

Let's have an image (gray-scale or even binary) as shown on the following figure at the left hand side, the goal is to generate a list of points i.e., coordinates in the form of (x,y) for each pack of ...
2k views

### Detection of circles (ellipses) in 2D point cloud

Given a set of points (2D) i.e., point cloud (PC), the question is about a robust, accurate and ...