Optical flow or optic flow is the pattern of apparent motion of objects, surfaces, and edges in a visual scene caused by the relative motion between an observer (an eye or a camera) and the scene.
Questions tagged [opticalflow]
400 questions
0
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2 answers
Sizes of input arguments do not match in cvcalcopticalflowbm opencv 2.4.7
I want to calculate optical flow using cvcalcopticalflowBM function in opencv 2.4.7
When I complied the belowed code. The error message is "Sizes of input arguments do not macth() in cvcalcopticalflowbm
I do not understand why it is. Please help me.…
user2745692
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viso2 "visual odometer got lost"
hi i am having some problem with the viso2 package's stereo odometry,it gives me "visual odometer got lost" when i am trying to run the launch file.I am currently using 2 Ueye UI-1226LE - USB 2.0 Camera for the stereo odometry.Below are the error…
user3222909
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1 answer
Optical Flow Color Map in OpenCV
I am trying to calculate and display dense optical flow in OpenCV using the farneback method. I found an example that uses CUDA functions to generate that and display the color map which I used as a base for my own code.
Optical flow…
user3128527
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1 answer
opencv optical flow does not detect most of the vectors
I'm using optical flow on a traffic video which are relatively small (288 x 360) and I have a problem. I can't get the optical flow vectors of some places in the frame.
This image shows the points that were detected as "good features to track" by…
soroosh.strife
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2 answers
onPreviewFrame not being called on Nexus 4 phone ... but is on Emulator
public boolean openCamera() {
Log.i(TAG, "openCamera");
releaseCamera();
mCamera = Camera.open();
if (mCamera == null) {
Log.e(TAG, "Can't open camera!");
return false;
}
…
user678392
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0
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1 answer
cvCalcOpticalFlowPyrLK not working as expected
I know this is a well documented problem but I didn't manage to find a satisfactory solution online. Here goes.
I am using cvCalcOpticalFlowPyrLK to track motion of feature points. I find the feature points with cvGoodFeaturesToTrack and refine it…
KelvinIPE
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Optical flow and focus of expansion in OpenCV
I am currently working on a project that requires me to find the focus of expansion using optical flow.
I currently have the optical flow and am using the formula from pages 13-14 this…
user2684493
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Why is the lines of optical flow are not drawn in my code
I'm trying to use the optical flow, but optical flow lines are not drawn and instead only points, what's the problem ?
Here is the source code of the project. Looked through the debugger. GDB shows that always p0.x = p1.x and p0.y = p1.y. but why ?…
user1886376
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2 answers
How to change if i only wanna to detect half of the image using cvgoodfeaturetotrack
cvGoodFeaturesToTrack
(frame1_1C, eig_image,
temp_image,
frame1_features,
&number_of_features,
.01,
.01,
NULL);
What value can i put in the mask parameter if i want to detect only half of the image??
Aaron
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How do i actually set optical flow on half of the image captured?
I already had an optical flow code implemented using C++ in OpenCV. However, i would like to detect optical flow in half of the image frame. Which part should i edit? is it from this function below?
cvCalcOpticalFlowPyrLK(
frame1_1C, frame2_1C,
…
Aaron
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- 1
0
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1 answer
Combining Background subtraction and Opticalflow
I'm trying to make some moving object detection (segmentation of foreground moving object from background) with slow illumination changes (= background change). Sometimes osme parts of the object are of the same size of the background, so the blob…
nkint
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cvCalcOpticalFlowBM error
I have been trying to use OpenCVs cvCalcOpticalFlowBM for optical flow calculations in my application. I am doing something similar to:
IplImage* velX1 = cvCreateImage(cvSize((beforeGray->width - blockSize.width + shiftSize.width)/shiftSize.width,…
Michel
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1 answer
OpenCV Lucas Kanade optical flow
I am working ona code where i have to find the trajectories of all the corner points that i am interested in. So, for the same, i used LKPyr Optical flow, which uses the corner points of the previous image and finds them in the current image. I am…
Vivek Sharma
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3 answers
grouping motion vectors
I am using -Lucas-kanade algorithm to calculate the optical flow of a video sequences with openCV. I got the motion vectors. Now I want to group those motion vectors in some clusters.
the vectors which are near by each other I want to group them…
MMH
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cvCalcOpticalFlowPyrLK input image size
When using cvCalcOpticalFlowPyrLK, generated pyramids seem wrong for some input image size. I cannot find in documentation any reference to good input image size. Nevertheless it finds points. Does anyone know how this happens and how to fix…
Alessandro Pezzato
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