All Questions
Tagged with computer-vision camera-calibration
37
questions
2
votes
2
answers
168
views
Camera sensor artifacts next to edges in calibration images; what is causing these?
I am trying to image some ChArUco targets using a monochrome machine vision camera with a CMOS sensor and the attached images show the artifact I am observing:
2-pixel-wide bright vertical streaks ...
- 41
1
vote
1
answer
72
views
Projection Matrix -- where does it come from?
I've started with these series to teach myself image processing and I am wondering when the camera's projection matrix (i.e. intrinsic and extrinsic matrices) is calculated?
Is camera calibration a ...
- 113
1
vote
0
answers
127
views
calibrating camera using 3d objects such as rubik's cube?
Hello all hope everyone is doing fine.
I have a vision related problem where I want to calibrate my camera using a 3d object such as rubik's cube with known dimensions. I have a cube with 60mm length, ...
- 11
0
votes
2
answers
55
views
Fixing distortion in photographic reproductions
I am currently building a photographic setup which I intend to use to make reproductions of a large amount of transparencies(positive and negative film strips). As I will be using a fairly small (1&...
- 103
1
vote
0
answers
70
views
How is focal length estimated?
There are a number of approaches to calibrate cameras. In this process you estimate the intrinsic parameters using a checkerboard of known size.
I'm confused on how the focal lengths are found. The ...
- 854
3
votes
0
answers
883
views
Reprojecting an image to another viewpoint using planar homography
I have an image rendered by a simulated camera in Unity. Using this image and the known (virtual) camera pose it corresponds to, I would like to render a new image from another viewpoint. Having read ...
- 429
-1
votes
1
answer
41
views
Best targets to calibrate camera with long focusing distance
I am currently using a number of cameras with long focusing distance, i.e. >3m, and I want to calibrate them to find the intrinsic matrix.
My problem is that if I want to cover all or most of the ...
- 111
2
votes
1
answer
1k
views
How to apply rotation to extrinsic and intrinsic camera parameters post-calibration?
I currently have a set of intrinsic / extrinsic camera parameters, and am using them to project 3D world coordinates to the 2D image, using projection matrix $P = K[R | t]$.
My problem is that this ...
- 31
0
votes
0
answers
47
views
Equation of line in the Homogeneous coordinate system
Given two points P and Q we can convert them to the homogeneous coordinate system, compute their cross product and thus get the ...
- 167
0
votes
1
answer
108
views
How to calculate the plane at infinity? either in Matlab or Python
I tried to implement this function to compute the plane at infinity $n_\Pi$ from the equation:
where $w^{-1}$ is the image of the absolute conic IAC, $M_j$ is the Projection Matrix of image $j$,
but ...
- 167
0
votes
1
answer
168
views
Understanding legacy code: Algorithm to remove radial lens distortion
The method below to remove lens distortion from a camera was written more than ten years ago and I am trying to understand how the approximation works.
...
0
votes
1
answer
38
views
How can I infer the cost function from Kruppa's simplified equations
The following equations are Kruppa's simplified equations used in camera autocalibration. My objective here is to infer the cost function(Error Function) from this equations, So I can minimize the ...
- 167
0
votes
1
answer
516
views
Camera Pose Estimation from Vanishing Points
I want to estimate the pose of camera (Location and Orientation). Can I use Vanishing Points to get the location and orientation of the camera?
There is object in the image which I also know his size,...
- 3
2
votes
1
answer
502
views
What are the parameters of a calibrated spherical camera?
I'm aware if we have a pinhole camera model several parameters describe the specific camera (such as aspect-ratio, focal length, principal point, distortion parameters etc).
There're standard ...
- 425
1
vote
2
answers
8k
views
Camera calibration and extrinsic parameters for perspective transformation
I'm working in a photogrammetry camera and laser application where I need to measure a displacement in a specific plane, this is a quick diagram of the setup:
In order to get proper measurements I'm ...
- 137