# Questions tagged [3d]

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### Measuring non-planar objects in image

I'm working on a computer vision application (using openCV) and the goal is to measure the width of an object before/after it falls on a container. So after the fall its position will be random, ...
2k views

### 3D image segmentation

Re-written more specific question For the details of my segmentation algorithm, see the original question below. I have managed to improve the segmentation considerably by using a different strategy ...
136 views

### Upsampling Methods for Computed-Tomography

I have two sets of data of given Field of view, one of them only covers a subset of the FOV of the other. I therefore want to upsample the one with the larger FOV to combine it with the other one. So ...
106 views

### Phong Reflection Model Parameters

Question: Can anyone refer me the Phong reflection model parameters for a face image taken for web-cam? Details: I am doing 3D reconstruction of 2D images using 3D Morphable Model as in this paper ...
17 views

### Projecting 3D point to 2D image coordinates

I am trying to replicate the projections of a 3D point to 2D using the pinhole camera model and the formula $x = K * [R|-RC] * X$, where $x = s\begin{bmatrix} u\\ v\\ 1 \end{bmatrix}$, $K$ is the ...
38 views

### How to create 3D signed distance function?

I am trying to segment a 3D shape using levelset. I want to track shape movement in consecutive frames. Now I want to create a signed distance function matrix for ...
30 views

While reading the Wikipedia article on Bundle adjustment, I came across the following objective function used to represent the bundle adjustment problem. I have two questions regarding this objective ...
53 views

### How to reconstruct 2D flat image from a series of pictures of a tube

I have pictures of an oesophagus (ie a tube) taken under standard white light looking down the tube. I have about 10 images taken over 20cm in series. The image looks forward down into the tube and ...
98 views

### Sensor Data Fusion with Orientation Sensors in 3D Euclidian Space

Preconditions For measuring the position of a mobile device in 3D space, I utilize two sensors with different characteristics that measure device orientation. Sensor A (a combined sensor of ...
312 views

### What are the keywords to find an algorithm that detects embossed text from a 3d model?

Currently I am doing an acadmic research about an idea which came into my mind lately. I have a 3d model and I want to extract embossed text .. anyone knows any papers? or if it is already proposed? ....
41 views

### How to detect directional signal in three dimensions?

I have three orthogonal accelerometers that give accelerations in x,y and z dimensions. I'm trying to detect directional vibrations between certain frequencies. In other words, my input is 3d vector ...
8 views

### Denoising 3D matrix

Are there any standard techniques I can use to denoise a 3D matrix? I hope to apply something like simple SVD denoising methods (e.g., reconstructed the images with salient singular values) to a 3D ...
30 views

### Obtaining camera matrix for estimating shape of moving object

I have an object that is moving parallel to a stationary camera. I would like to use Structure from Motion or Shape from Silhouette to obtain the 3D points of the object. For that, I need to obtain ...
178 views

### Mapping ring asteroids in Elite Dangerous by image processing

In the game Elite Dangerous, which is an online spaceflight-based sandbox game set in a procedurally-generated galaxy, one of the most profitable in-game occupations is mining commodities from ...
54 views

### 3D reconstruction of moving object

I am pretty new to the field of 3D reconstruction and overwhelmed by the large amounts of different methods. I am trying to find the correct method for my use case: Setting: I have a stationary ...
24 views

### Compute $d^2$ entries of a 3D convolution faster than $O(d^3)$

Let $A,B\in \mathbb{R}^{d\times d\times d}$. The 3D circular convolution $\text{conv}(A,B)$ can then be computed as $F^{-1}(F(A)\odot F(B))$ where $F(\cdot)$ denotes the 3D discrete Fourier transform ...
7 views

### Poisson Meshing without filling holes

Currently I have a point cloud coming from a single depth camera (Microsoft Kinect for Azure). In the resulting point clouds there are of course occlussion and gaps. I wanted to create a mesh from ...
12 views

### KCS - 3D profile representation

I was reading Character Recognition Systems book and in section 2-3-2-3 a new kind of filter is introduced (instead of normal Gaussian filter) to reduce mask size and to prevent data loss by the name ...
21 views

### Switching camera angle based on several images

Given a number (3 or 4) of different images of a given subject from different angles, how do I interpolate to an angle that isn't available on any of the photos? What is this technique called and is ...
96 views

### How to filter a sequence of frames?

I'm have a sequence of 2-dimensional MxN frames. I have concatenated these frames to form a 3-dimensional MxNxT matrix. Now i want to filter this 3D volume by 2 types of filters (a 2D log-Gabor in xy-...
722 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 ...
768 views

### Distinguish between 2D and 3D objects according to depth

I'm trying to distinguish by code between a real 3D object and its picture - a 2D object, based on depth information. However the picture (= the 2D image) might be captured from noisy background, so I ...