tracking object in a video

Hello,

I have a video of someone who has an orange in his hand and my goal is to track this orange. First of all i have to create a ROI around this orange after the segmentation:

Left: the original video , Right: the video with segmentation to just have the orange.

Left: The ROI around the orange, Right: The virtual camera who follows the orange thanks to the ROI.

First of all i read the video and after, with a while, i must detect the orange in each frame:

videoFileReader = VideoReader('VT.mp4');;
VideoPlayer = vision.VideoPlayer('Position',[100,100,1920,1080]);

%% Detect oranges in each frame
while hasFrame(videoFileReader)
    videoFrame = readFrame(videoFileReader);
    Bin=videoFrame(:,:,1);
    frame_binarise=imbinarize(Bin);
    surface=sum(sum(frame_binarise));
    [X_barycentre, Y_barycentre] = calcul_Barycentre(frame_binarise);
    X=floor(X_barycentre);
    Y=floor(Y_barycentre);
    se = strel("diamond",1);
    contour = frame_binarise - imerode(frame_binarise,se);
    imshow(frame_binarise);
end

My baryencenter function:

function [X_barycentre, Y_barycentre] = calcul_Barycentre(img)
[LIG,COL]=size(img);
% Surface
S = sum(sum(img));
% X_barycentre
sumX = 0;
for l=1:1:COL
    sumX = sumX+l*sum(img(:,l));
end
X_barycentre = sumX/S;
% Y_barycentre
sumY = 0;
for k=1:1:LIG
    sumY = sumY+k*sum(img(k,:));
end
Y_barycentre = sumY/S;

So my probleme is how to make the ROI around the orange ?

[darova]

You have center of the orange and want coordinates of rectangle? Is it correct?

[Benjamin Lemoine]

Yes i want to have a rectangle like the second photo at left

Answer 1

[darova]

if these [X_barycentre, Y_barycentre] are coordinates of a center

Use imcrop to crop the image

h = 50;         % side of rectangle
I1 = imcrop(videoFrame ,[X_barycentre-h/2 Y_barycenre-h/2 h h])