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# Tag Info

Accepted

### How do I estimate the pose of a camera looking at a flat horizontal surface?

Your problem is called pose estimation. The OpenCV function is called solvePnP(). Be aware that the intrinsic camera matrix must be known in advance. If you don't ...
• 531

### How do I estimate the pose of a camera looking at a flat horizontal surface?

All of this is written assuming that you have already calibrated the camera for its intrinsic matrix. If you have not done this, then you need to do so beforehand, or you need to look to the answer ...
• 12.9k

### Camera Calibration - why do you have to move the calibration board?

This is due to the optimization problem being rather high-dimensional (around 11 parameters). With only a single observation of the calibration board, there would be multiple possible combinations of ...
• 156
Accepted

### Math for projecting 3d world point to VR image coordinates

Your images look like being shot with an angular fisheye projection . Also, to account for epipolar geometry of stereo images, you should include the fundamental matrix into the transform engine of ...
• 1,749

### Estimating Plane Pose Without Knowledge of Intrinsic Camera Parameters

I think there is a mistake in this part: $$\vec{n} = K \vec{R_1} \times K \vec{R_2} = det(K)K^{-T}(\vec{R_1}\times\vec{R_2})$$ In particular, if $\alpha \neq 1$ \begin{...
• 31
Accepted

### Pinhole camera model from houdini parameters

This is a long topic to fully explain. I will try to write shortly, so please excuse the brevity. Standard computer vision projection (ignoring distortion like Houdini) follows:  \mathbf{x} = \...
• 5,465
Accepted

### Intuition about tag pose estimation accuracy

The size of the tag is an important parameter. But it is a secondary parameter. The key parameter that we are looking at here (and one that is not easy to estimate) is Signal to Noise Ratio (SNR). So, ...
• 10.7k

### How do I estimate the pose of a camera looking at a flat horizontal surface?

I deleted my previous answer because I was glued in some convoluted calculations and the question was answered with a nice on-the-shelf software answer. However since then I continued to look into ...
• 507
1 vote
Accepted

### How do I estimate the position and orientation of two instruments looking at the same target?

As far as I know, the best way to do this is with nonlinear optimization. This is what is implied in the OpenCV page about its camera calibration routines. Write an equation that generates your ...
• 12.9k
1 vote
Accepted

### Understanding difference in rotation and translation

Homography has an interpretation as a change of perspective or movement of the "camera". I think your example casually refers to the apparent "rotation" of the camera in the ...
• 171
1 vote

### Find camera pose by knowing triangle coordinates

No. No. You can't. Not completely at least. With only three points, the math has two solutions. Your triangle could be tilted in one of two positions. Like picking a square root. From a single ...
• 7,590
1 vote
Accepted

### Camera Pose Estimation from Vanishing Points

You can use the vanishing points to calibrate the camera. I recommend reading Chapter 8.6 of Multiple View Geometry in Computer Vision [ http://www.cambridge.org/9780521540513 ] Even better, if you ...
1 vote

### Camera Calibration - why do you have to move the calibration board?

Digital cameras sample the incoming optical EM or photonic field with a fixed grid of CCD or CMOS transistors. Since the sampling grid (rectangular or perhaps hexagonal) is not angularly symmetric, ...
• 35.6k
1 vote
Accepted

### Camera and laser scanner calibration final approach questions

The solution I gave in the other answer assumed that the plane in question was fixed relative to the camera location. Thus a mapping from the 2D pixel locations to a 2D location on the plane could be ...
• 7,590

Only top scored, non community-wiki answers of a minimum length are eligible