Tagged Questions

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.

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Eye tracking - estimating face position

I want to create an eye-tracker using EmguCV. I came across the problem of calculating the face position, which I need to get in order to correctly estimate the gaze of a person. I wanted to use the ...
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1answer
39 views

Faster alternatives for calcOpticalFlowSF

Is there any faster alternatives for calcOpticalFlowSF? Its just sooo slow and wanna run this thing with a sequence of frames coming from a video. How can I do that?
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1answer
234 views

OpenCV C++ Optical Flow based segmentation code throws Exception

From one of the SO answers, for segmentation using optical flow Dense optical flow is required. I modified this code . It uses calcOpticalFlowFarneback function to calculate the dense flow field ...
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1answer
28 views

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 ...
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1answer
32 views

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? ...
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1answer
125 views

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 ...
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1answer
153 views

OpenCV's calcOpticalFlowPyrLK throws exception

I have been trying to form a small optical flow example with OpenCV for a while now. Everything works except the function call calcOpticalFlowPyrLK, which prints the following failed assertion in the ...
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1answer
130 views

Optical flow based segmentation

Hi I would like to segment objects in a video sequence based on optical flow (as suggested in this answer), I am using opencv and have been able to generate a flow field for two successive frames ...
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2answers
86 views

Are there any collections of Optical Flow code?

I'm currently searching for optical flow code of all sorts (mainly implementations of algorithms), for the purpose of gathering them into a list, which can later be published in the form of a website. ...
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1answer
79 views

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 - ...
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1answer
169 views

Horn-Schunck optical flow calculations

I was studying the Horn-schunck method for calculating optical flow in videos. My code is in C, which would mean i am implementing all of the algorithms from scratch including gray-scaling the image, ...
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2answers
381 views

OpenCV - Brox Optical Flow - Exception in opencv_core244d!cv::GlBuffer::unbind

Has anyone managed to get the Brox dense optical flow algorithm in OpenCV working? Here is some code: { // Load images cv::Mat PreviousFrameGrayFloat; // Has an image in format CV_32FC1 ...
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1answer
279 views

How to get cv::calcOpticalFlowSF to work?

I am useing the 2.4.4 version of OpenCV. - i know its a beta but there is an example about cv::calcOpticalFlowSF the method in the example folder called: simpleflow_demo.cpp. But when i copy this ...
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143 views

DUAL-TV-L1 OpenCV 2.4.4 [closed]

has somebody used the cv function "Ptr<DenseOpticalFlow> createOptFlow_DualTVL1()" from the OpenCV Library 2.4.4 yet? Can someone provide an simple example code? OpenCV doc! Thank you a lot! ...
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4answers
281 views

Real Time Optical Flow

I'm using optical flow as a real time obstacle detection and avoidance system for the visually impaired. I'm developing the application in c# and using Emgu Cv for image processing. I use the Lucas ...

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