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11 votes
Accepted

Markov (Chain) image generators?

I've implemented this recently, basically it counts how many times each specific colour borders another colour to make up a frequency table. To generate an image, a random colour and position are ...
Jonno_FTW's user avatar
  • 226
5 votes
Accepted

Iterative camera calibration - No convergence

I have to tell you. I implemented this algorithm (even double checked with other experienced people), however no luck. I guess, this worked for the authors, but with our data there was really no ...
Tolga Birdal's user avatar
  • 2,249
5 votes
Accepted

Algorithms to extract trajectory lines out of 3D point clouds

I will summarize a couple of possibilities: As a baseline, I would begin with a Hough transform kind of approach: Iterative Hough Transform for Line Detection in 3D Point Clouds Christoph Dalitz,...
Tolga Birdal's user avatar
  • 2,249
3 votes
Accepted

Evaluate 3D Shape Descriptor

3D local feature descriptors for shapes are very well studied. Typically, people tend to represent the input as a set of points (point clouds) and try to characterize the local neighborhoods with ...
Tolga Birdal's user avatar
  • 2,249
3 votes
Accepted

Compute point-spread-function between original and blurred image

We construct an operator based on the assumption that the system is a linear space invariant system. The blurred image is denoted $b$ and the input is denoted $x$. Since the convolution is commutative,...
Ron's user avatar
  • 725
2 votes

Is the inverse radon transform considered a linear operation?

For an operator $R$ to be linear, it has to satisfy two conditions: $R(f+g) = Rf + Rg$ for any two operands $f,g$; $R(\alpha f) = \alpha Rf$ for any operand $f$ and (real or complex) number $\alpha$. ...
Wolfgang Bangerth's user avatar
2 votes

Algorithm to determine flat surfaces and camera orientation without specialized hardware

You are quite right, Augmented Reality benefits a lot from a combination of video/image analysis together with the data from motion sensors. Quote from Apple ARKit: Understanding World Tracking: To ...
Anton Menshov's user avatar
  • 8,702
2 votes
Accepted

Polygon approximation with a circle

They just curve fit the two equations $$ x(\omega) = h - b \sin(\omega) ~,~~ y(\omega) = k + a \cos(\omega) $$ using a nonlinear curve fitting algorithm. However, the accuracy of the fit depends ...
Biswajit Banerjee's user avatar
2 votes

How to find fundamental matrix based on other fundamental matrix and camera movement?

I cannot help but suspect that the working function you've provided is less efficient than it can be, but I must also admit that I have only dabbled in computer vision myself. Here's a suggestion for ...
Robert Bassett's user avatar
1 vote

Detect all geometric objects in an (edge) image

I propose a simple solution, but whether it works will depend on how well line following can separate the groups and how fast the ellips fitting works. Step 1, follow lines to separate the edge points ...
Thijs Steel's user avatar
  • 1,733
1 vote

Detect all geometric objects in an (edge) image

A. Convex polygon inside convex shape Since all objects are convex, if two endpoints of a line segment are inside an object the entire line is in the segment, and if all the edges of a convex polygon ...
Bob's user avatar
  • 156
1 vote

Algorithms to extract trajectory lines out of 3D point clouds

When the points belong to more than one curve, it will first be necessary to cluster them into curves. A possible approach is described together with a reference implementation in Dalitz, Wilberg, ...
cdalitz's user avatar
  • 481
1 vote

Methods to implement floor dirt detection algorithm

Here are some suggestions: Whatever method you try, look at a large number of dirty floor samples to get an idea of the range of things - is it a darker area, is it streaks, etc. For a simple idea, ...
SolverWorld's user avatar
1 vote

Integral image resizing

The formula says that the resized (smaller) image pixel at (x,y) is a bilinear approximation of the pixel at location (2ax+b, 2ay+b). Ignoring b for the moment, you can see that the scale factor (or &...
SolverWorld's user avatar
1 vote

Can software remove all distortion from image taken with 180-degree lens?

Software could never get rid of all the effects of distortion. The reason is that, if you do not operate in the hardware level, you could only make approximations about the real effects. Distortion ...
Tolga Birdal's user avatar
  • 2,249
1 vote

Markov (Chain) image generators?

Blog post on an experimentation using Markov to recreate art: https://magenta.as/using-machine-learning-to-make-art-84df7d3bb911 Code is on github made by @william-index: https://github.com/william-...
Gustavo Faria's user avatar

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