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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 ...
1 vote
1 answer
74 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 ...
1 vote
0 answers
130 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, ...
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&...
-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 ...
-1 votes
1 answer
159 views

camera calibration change orientation of axis

I want to solve for the extrinsics by using direct linear transformation on corresponding 3D LIDAR points and 2D camera points. I already have the intrinsics. Problem is, points behind the camera ...
2 votes
1 answer
1k views

How to warp a pixel patch to another camera

I have two cameras with rotation and translation starting from the world origin and a patch in the first camera's reference coordinate system. I want to warp this patch into the second camera's ...
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 ...
3 votes
0 answers
892 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 ...
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 ...
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 ...
0 votes
1 answer
169 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
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 ...
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 ...
0 votes
1 answer
518 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,...

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