how to find the location of optical flow (head) vector?

Answer 1

[Vedant Shah]

Hi @zunash ahmad,

To determine the location of an optical flow vector, you can calculate the optical flow between two consecutive frames of a video or two images. This can be achieved using the “estimateFlow” function, which is part of the Computer Vision Toolbox. For further information, refer to the documentation using the following command in the MATLAB command line:

web(fullfile(docroot, "/vision/ref/opticalflowhs.estimateflow.html")) 

Below is a basic code example for obtaining the location of optical flow vectors:

% Read two consecutive frames 
frame1 = imread('Frame1.png'); 
frame2 = imread('Frame2.png'); 

% Convert to grayscale 
grayFrame1 = rgb2gray(frame1); 
grayFrame2 = rgb2gray(frame2); 

grayFrame2 = imresize(grayFrame2, size(grayFrame1)); 

% Initialize optical flow object 
opticFlow = opticalFlowHS(); 

% Calculate optical flow for the first frame 
flow1 = estimateFlow(opticFlow, grayFrame1); 

% Calculate optical flow for the second frame 
flow2 = estimateFlow(opticFlow, grayFrame2); 

% Display the second frame 
imshow(frame2); 
hold on; 

% Plot the flow vectors 
plot(flow2, 'DecimationFactor', [5 5], 'ScaleFactor', 10); 
hold off; 

Executing this code will display the image with the optical flow vectors as desired.