All Questions
Tagged with perspectivecamera computer-vision
18
questions with no upvoted or accepted answers
2
votes
0
answers
308
views
OpenCV Perspective Transform with Reference Object
I'm a beginner with OpenCV, and I'm currently building out a project with a goal to find some relevant dimensions of a building (for now, just width and height in feet).
See image below:
I added a ...
- 21
2
votes
3
answers
4k
views
How to turn any camera into a Depth Camera?
I want to build a depth camera that finds out any image from particular distance. I have already read the following link.
http://www.i-programmer.info/news/194-kinect/7641-microsoft-research-shows-...
- 21
1
vote
1
answer
1k
views
How to find a four point polygon approximation with OpenCV?
So I have a problem that requires me to get a perspective transform on a series of numbers. However, in order to get the four point transform, I need the correct points to send as parameters to the ...
- 33
1
vote
0
answers
291
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calculating topdown/birds eye map from images with a sequence of poses
I am trying to build a topdown birds eye map of the road surfaces from a sequences of images, each which I know the ground truth poses. The data is from the KITTI dataset, of which I know the distance ...
- 33
1
vote
0
answers
486
views
Retrieve original coordinates of a pixel from a warped image
I was trying to follow along with four-point-transform blog post with slight modifications using Python-3.6.
First I obtained four_point_transform of the given image. After getting the warped image, I ...
- 36
0
votes
0
answers
27
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Image analysis with MATLAB: transforming an image taken at an angle back to direct view
I have a series of photographs taken at an angle, like this:
What I would like to do is "straighten" these photographs into direct view:
The above examples are taken from this Photoshop ...
- 101
0
votes
0
answers
119
views
How to do Perspective Transformation of Image
Suppose I have colmap camera poses, is it possible and how to obtain a new view of input image I (planar object) from a different viewpoint/camera pose using those poses?
Colmap camera poses has ...
- 1
0
votes
0
answers
61
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Align horizontal lines in projected view of matrix via opencv
I have two different matrices A (shape 5, 11) and B (shape 5, 2).
I want to have a projected view of each of these matrices.
Unfortunately, the horizontal lines that are separating different values, ...
- 57
0
votes
0
answers
116
views
How to turn these camera properties into standard calibration?
I have a product of a long closed company whose camera properties i need to figure out. I have the following info about the camera (e.g. FOV), and wonder how i turn this into standard
camera ...
0
votes
0
answers
412
views
Estimate camera pose from 3 points with OpenCV
I have a straightforward (I guess) problem to solve with opencv:
I have 3 non-colinear Points in the 3D system given in cm:
Point A = Point(.., .., ..);
Point B = Point(.., .., ..);
Point C = Point(....
- 2,652
0
votes
1
answer
287
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Measuring objects in a photo taken by calibrated cameras, knowing the size of a reference object in the photo
I am writing a program that captures real time images from a scene by two calibrated cameras (so the internal parameters of the cameras are known to us). Using two view geometry, I can find the ...
- 532
0
votes
0
answers
276
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estimation of the ground plane in pinhole camera model
I am trying to understand the pinhole camera model and the geometry behind some computer vision and camera calibration stuff that I am looking at.
So, if I understand correctly, the pinhole camera ...
- 10.9k
0
votes
2
answers
639
views
Calculate homography by two parrallel lines
I know two lines
（in the form Ai x'+Bi y'+ Ci =0）
on the image, which is a pair of parallel line
（in the form x = ki）
on a real word plane（just like a pair of road traffic marking line).
How ...
0
votes
0
answers
413
views
How to find the coordinates of the fourth vertex of a square in a projective perspective
If I suppose that I know the coordinate of three points (eg. A'B'C') in a 2D coordinate system of A'B'C'D', my question is how can I find the coordinate of the fourth point D' (the same question for A'...
- 2,304
0
votes
1
answer
486
views
Keystone effect
I have a fixed pinhole camera. I aim it a flat panel and take an image. I tilt the flat panel up and take an image. Is there some way to convert the pixels to real-world coordinates, getting rid of ...
- 41