After converting video into frame, and appling frame differencing method to subtract two image, now i want to draw boundary in foreground of video, how?

%%Extracting & Saving of frames from a Video file through Matlab Code%%

clc;

close all;

clear all;

% assigning the name of sample mp4 file to a variable

filename = 'C:\Users\Hp\Desktop\xyz.mp4';

%reading a video file

mov = VideoReader(filename);

%getting no of frames

numFrames = mov.NumberOfFrames;

%setting current status of number of frames written to zero

numFramesWritten = 0;

%for loop to traverse & process from frame '1' to 'last' frames 

for t = 1 : numFrames

currFrame = read(mov, t);    %reading individual frames

opBaseFileName = sprintf('%3.3d.png', t);

opFullFileName = fullfile('C:\Users\Hp\Desktop\col1', opBaseFileName);

imwrite(currFrame, opFullFileName, 'png');   %saving as 'png' file

progIndication = sprintf('Wrote frame %4d of %d.', t, numFrames);

disp(progIndication);

numFramesWritten = numFramesWritten + 1;

end       %end of 'for' loop

progIndication = sprintf('Wrote %d frames to folder "%s"',numFramesWritten, 'C:\Users\Hp\Desktop\col1');

disp(progIndication);

%End of the code

%frame differncing code

I=imread('C:\Users\Hp\Desktop\col\001.png');

   I1=rgb2gray(I);

imshow(I1);

J=imread('C:\Users\Hp\Desktop\col1\001.png');

I1=rgb2gray(I);

J1=rgb2gray(J);

imshow(I1);

imshow(J1);

K=I1-J1;

figure;

imshow(K);

title('SUBTRACTED IMAGE ');

[Image Analyst]

http://www.mathworks.com/matlabcentral/answers/13205#answer_18099

[komal]

thank you for the above code. I need to subtract frames from each other like frame1- frame 2 and frame2-frame3 and so on till videos end. Then want to display the each result of differences on the graph

Answer 1

[Image Analyst]

Use rectangle() or plot() to put lines into the overlay. Use text() to put words/strings into the overlay. You might have to put "hold on" first though.

[Mohammedashraf Shaikh]

any example please if possible,

and how to get coordinate so that i can draw rectangle on it

actually i want to draw rectangle on a object on video which is different from reference video

[Mohammedashraf Shaikh]

The above two images are subtracted and I obtained this subtracted image. Now I want to draw a rectangle on the video containing the boy. How do I get the coordinates or anything else?

[Image Analyst]

Threshold it. Call bwareafilt() to extract the largest blob. Call bwlabel(), then call regionprops() and ask for the bounding box. Then call "hold on" and call rectangle() to place the bounding box on the video. See if you can do those steps. Here's a start

binaryImage = subtractedImage > 30;
binaryImage = bwareafilt(binaryImage, 1);
labeledImage = bwlabel(binaryImage);
props = regionprops(labeledImage, 'BoundingBox');
hold on;
hRect = rectangle('Position', props.BoundingBox);