# Tagged Questions

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24 views

### Counting percentage of fouling on a surface

I am completely new to image processing and python. I hope I can find some help here. I am trying out a project on detecting fouling% on a ship hull using raspberry pi. I am trying to learn how this ...
24 views

### Retrieving camera orientation from DLT parameters

I currently have 12 DLT parameters to map 3D points to 2D pixels, the projection/conversion works nicely. Now, I am able to retrieve the camera position from the parameters using equation [25] from ...
278 views

### How to calculate the scale, rotation angle and translation between 2 images if we know the homography result matrix?result

I got the result of findHomorgraphy in OpenCv. As below: Homography transform matrix: [-1.1534205416542787 0.7834287271121142 527.9064589440736 -0.2415444621693116 0.16412191792642924 ...
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### mixed composition of homography and Euclidean transform matrices

The question is quite theory related I guess and I haven't been able to find a clue for the answer. Probably, background in abstract algebra will work? $H_0TH^\dagger$ Is this composition a ...
85 views

### How are the scaling parameters included (extracted from) an essential matrix?

An essential matrix relates corresponding points between two images assuming that a camera satisfies the pinhole camera model, and can be expressed as: $$E=K'^TFK$$ where K is the calibration and F ...
79 views

### Calibration (intrinsic) parameters of a virtual camera with some known information

I need the calibration matrix of my simulated camera, I am trying to fully comprehend and follow the steps from Step by Step Camera Pose Estimation for Visual Tracking and Planar Markers as well as ...
25 views

### Homography for calculating displacement

Homography process gives information between two images and we can use it for panoramas. It gives skew, rotation and scale information. These information can be used to calculate/ estimate relative ...
123 views

### Obtain motion between image features by means of the homography matrix

I have been reading several really good answers about how to obtain camera pose (rotation, translation, etc), such as this one and this one, but I am not sure how this applies to my problem. My ...
13 views

### What is the state of the art in recovering homography without using point correspondence?

I am interested in the ones that don't make any assumptions about known points, and just uses the shapes to estimate the homography. I found this one, which seems to be done in 2009, https://www....
189 views

### homography matrix problem

i have mini project to do about homography , but i am really a beginner in matlab . i have calculated the homography matrix easily by taking a set pixels from both images but the problem is how to ...
5k views

### How to apply a 2D -2D homography matrix to an image?

I have a mini project to do about homography, but I am really a beginner in Matlab. I have calculated the homography matrix easily by taking a set pixels from both images but the problem is how to ...
357 views

### What methods can be used to compute homography

I am trying to understand panorama stitching. I've come to a conclusion that homography is one of the fundamental parts in the process. Now I am trying to make sense of all the information from ...
3k views

### Why normalize the data set before applying Direct Linear Transform

Direct Linear Transform (DLT for short) is a method of homography estimation, it solves the overdetermined linear system via SVD $$Ah=b$$to find a solution $h$ under constraint $\|h\|=1$. Actually it ...
2k views

### Ground plane estimation from a single image (was: confusion about homography and calibration camera parameters)

I'm new to this multiple view geometry issues and I'm a little bit lost, and some concept are not clear at all. I have a calibrated camera ( = I have distortion coefficents, field of view, and with ...
2k views

### Calculating a homography based on detected lines

I know you can calculate homographies from image to camera plane using correspondence points between a "perfect model" and the image points. I'm doing it for a football pitch/field, and have used ...
417 views

### Apply Low Pass (Smoothing) Filter on a Set of Matrices and Reject Outliers

Given a set of a $3$ by $3$ matrices ${H}_{i}$. Each matrix is an Homography matrix. They are used to stabilize Video Stream. Yet some of them are outliers which creates "Jumps" in the "...
18k views

### Step by Step Camera Pose Estimation for Visual Tracking and Planar Markers

I have been working on the topic of camera pose estimation for augmented reality and visual tracking applications for a while and I think that although there is a lot of detailed information on the ...