All Questions
Tagged with computer-vision camera
21
questions
29
votes
2
answers
33k
views
How does resizing an image affect the intrinsic camera matrix?
I have a camera matrix (I know both intrinsic and extrinsic parameters) known for image of size HxW. (I use this matrix for some calculations I need).
I want to use a smaller image, say: $\frac{H}{2}\...
- 887
10
votes
3
answers
3k
views
Camera calibration/pin hole camera model and working out 3d position
I have a calibrated camera and have the intrinsic parameters. I also have the extrinsic parameters relative to a point (the world origin) on a planar surface in the real world. This point I have set ...
- 453
5
votes
2
answers
3k
views
How to estimate radial distortion from lens characteristics?
Is there a way to estimate the radial distortion coefficients without calibration, given the lens characteristics, such as its diameter and its focal length?
Typically for camera calibration a ...
- 5,101
4
votes
3
answers
1k
views
Detecting bullet holes using Python with camera or sensors
I am trying to build a system to detect bullet holes in paper. I've read many StackOverflow threads but not a single one satisfied me. Current methods, which I am using, are good but not perfect and ...
- 41
3
votes
2
answers
6k
views
Camera calibration using multiple images
I am trying to get the hang of camera calibration. For this purpose, I have mainly watched this lecture on youtube: Lecture 12: Camera Model by UCF CRCV. I believe that I understood the main ideas:
...
- 183
3
votes
0
answers
814
views
Correct Fish Eye camera Radial Distortion and blurry effect at the image edges
There are a lot of questions regarding this topic ,but I am trying to get a more clear picture from these questions.
I am trying to calibrate a fish eye camera and I am using OpenCV omnidir class ...
- 131
2
votes
3
answers
346
views
Can you average out focal length from different camera calibration sessions?
If I perform a number of camera calibration routines at a fixed resolution, with various sizes of calibration patterns (like checkerboards), at various distances and get various values for focal ...
- 91
2
votes
1
answer
84
views
Given some parameters, how do you determine how much of an image sensor an object will consume? [closed]
If I have the details of a scene and a camera, how can I tell how much of my camera's image sensor will be taken by a certain object in space?
For example, if I have a painting that is 1m by 1m, it ...
- 31
2
votes
1
answer
562
views
Stereo triangulation similar triangle derivation
I understand that the similar triangles are the red and blue triangles. I'm trying to understand where $T + x_r - x_l$ comes from. I understand we are trying to compute the length of the base of the ...
- 23
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
1
vote
2
answers
322
views
Estimate camera generalized velocity from consecutive frames
Let's suppose I have a camera which can move freely in 3D space and has 6 degrees of freedom. Is it possible to estimate the linear and angular velocity of the camera from 2 or more consecutive frames?...
- 141
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, ...
- 11
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
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
0
votes
1
answer
323
views
Pinhole camera model from houdini parameters
From a simulation with Houdini software I retrieved these parameters:
Camera position: -0.675839, 33.5945, 0.0318854
Camera Rotation: 0.0318854, 92.4693, 0.1
Focal Length: 52.5172 mm
Image size: 1920 ...
