# Tagged Questions

he goal of computer vision is an automatic extraction of information out of images. It includes methods for acquiring, processing, analysing, and understanding images and high-dimensional data from the real world in order to produce numerical or symbolic information, e.g., in the forms of decisions. ...

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### Pure math questions arising in computer vision, and the need for mathematicians to solve them [closed]

I've read in several articles/answer written by CS (grad) students or other people that the advanced knowledge of pure math that's required for certain areas of computer vision is sometimes too high ...
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### Markov (Chain) image generators?

Markov Chains can be used to generate, or auto-complete, text. https://en.wikipedia.org/wiki/Markov_chain#Markov_text_generators Training text is read, and some information about the text is ...
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### Fitting orthogonal planes to a point set

I have a set of 3d points to which I want to fit two planes. I know the assignment of points to the planes so I don't need any RANSAC or similar. Currently, I'm using a PCA-based approach to fit two ...
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### How to train a model to classify object trajectories?

I have a tracker that outputs the trajectory $(x,y,z)$ of an object (e.g., a can). I want to use these trajectories to train a classifier (i.e., SVM) in order to infer the activity that the person ...
91 views

### Matrix free finite elements method for visualization in process tomography

I am Computer Scientist and now I am interested in matrix multiplication on GPUs. My research are focused on matrix free finite elements method where I multiply sparse matrix. Sparse matrix could ...
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### Classification of observations depending on its trajectory

I'm afraid the title is terrible, but I don't know how to summarize this problem in a few words. Using an instrument, we are monitoring the trajectory of several objects during a period of time. We ...
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### Is it possible to locate an image in a video using MATLab?

I'm not a huge programmer, but if it'll save me lots of time, that's when I code (given that it's possible). I know MATLab has a Computer Vision Toolbox, so my question is: is it possible to program ...
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### Algorithm: Extracting motion frequency from video

I was wondering if anyone knows of any algorithms or projects that can detect the frequency of a motion from a video clip. Like if I had a video of a bouncing ball with constant frequency, could an ...
314 views

### Image recognition on Raspberry Pi

I'd like to distinguish different types of beers in my fridge using a Raspberry Pi. I saw a very good tutorial on Adafruit that utilized OpenCV for face recognition. Can these same face recognition ...
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### What is Precision-Recall Curve? [closed]

I have a data mining assignment where I make a content-based image retrieval system. I have 20 images of 5 animals. So in total 100 images. My code returns the 10 most relevant images to an input ...
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### Interpolation by Solving a Minimization Problem (Optimization)

I will try to give the motivation behind this problem and later the math formality. Given a grayscale image (1 Channel - M by N Matrix). Someone marks some pixels as anchors. Now, you need to ...
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### Rank of image intensity matrix

I've been reading a paper about using Matrix Completion for Photometric Stereo but I am having some troubles in section 2.2 trying to understand why irrespective of the number of pixels and the number ...
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### How to detect smiles using OpenCV and IntraFace?

I have installed OpenCV and IntraFace, now the code can detect landmarks on the face, like this : Now how can I convert this to a smile detector? I have the landmark points as an array, so I ...
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### Is it possible to generalize the two view Sampson error to multiple view cases in computer vision?

In multiple view geometry of computer vision, there is a geometric error called Sampson error which is very useful in the nonlinear estimation of fundamental matrix....
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### A Filter is Sum normalized to 0 and square normalized to 1

Firstly, About the Hierarchical Model And X (HMAX model), i still don't understand what is the difference between the "Original model" and "Standard model". Does in Standard, we use imfilter not conv2 ...
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### How to recover the 3x4 pinhole camera from 9 parameters

I downloaded the bundle adjustment data from this link: original data for bundle adjustment which is the supporting data for a paper titled: Bundle Adjustment in the Large I want to use the data ...
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### Environment for implementing/testing Computer Graphics algorithms [closed]

I need to code up a computer graphics algorithm for Surface Registration. Briefly surface registration is the process of finding "optimal" one-one correspondence between surfaces, where the meaning ...
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### Network Flow - based optimization in renowned paper appears to have a wrong step

This is probably going to be an easy question for most people and embarass me. I've been reading the Zhang et al. 08 paper on detection-based tracking through network flows: http://iris.usc.edu/...
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### Explanation of LidarBoost Algorithm?

I am trying to understand the LidarBoost algorithm as explained in this paper (PDF warning). My apologies if this isn't the appropriate exchange; I've posted in DSP, but I didn't get a response there, ...
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### Pixel-To-Angle Transformation in Camera Image

I'm trying to localize points I see in a camera image in terms of azimuth and elevation and match points between shots. Individual shots should differ only in rotation around the camera's center (...
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### How do you formulate the linear least-squares method for radiometric calibration?

In Debevec and Malik (mentioned similarly in Forsyth and Ponce's Computer Vision: A Modern Approach) they highlight a method of solving the camera response function using linear least-squares. We ...
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### Shearing and Hartley's rectification

I'm using Richard Hartley's rectification algorithm to rectify a pair of images before performing stereo disparity computation. The problem is I'm observing shearing in one of the rectified images and ...
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### Where can I find public datasets of images mostly dominated by contour?

I am about to start research for my thesis. I am trying to find public datasets of images mostly dominated by contour meaning (An outline, esp. one representing or bounding the shape or form of ...
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### Recover curves from noisy collection of points

Background: I'm trying to make a system that tracks a number of bubbles in a video I'm implementing the bubble detection in the single image case using the Circular Hough Transform. Due to occlusion,...
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### Conjugate Gradient with Hierarchical Basis Functions: How can the hierarchical base be decomposed?

I'm trying to implement a Conjugate Gradient solver using Hierarchical Basis Functions, following this paper. In section 3 the paper says that the hierarchical basis matrix $S$ can be decomposed into ...
343 views

### Fitting a grid to an STM image

Suppose I have a scan from an STM image (very much like the things you see here). Suppose I have a simple square lattice with lattice parameter a. What I'd like to do is to numerically find the ...