Drawing a bounding box around foreground objects

Hello Everyone.

I have applied a backgrund subtraction algorithm called frame differencing it is working very well I can easily detect the moving objects from the video now I want to draw the rectanlge or bounding boc around the detected objects.I have used the connected component labelling here like that below provided by Image Analyst.But I could not draw the bounding box..Any help is appreciated.

figure(3);imshow(fg1);

drawnow;

hold on;

labeledImage = bwconncomp(fg1,8);

measurements = regionprops(labeledImage,'BoundingBox','Centroid');

if length(measurements) == 0

% No blobs found.

fprintf('Done!\n');

continue; % Skip to the next frame.

end

totalNumberOfBlobs = length(measurements);

for blobNumber = 1:totalNumberOfBlobs

bb = measurements(blobNumber).BoundingBox;

bco = measurements(blobNumber).Centroid;

rectangle('Position',bb,'EdgeColor','r','LineWidth',2)

plot(bco(1),bco(2),'-m+')

myCaption = sprintf('(x=%.1f, y=%.1f)', bco(1), bco(2));

text(bco(1)+15,bco(2), myCaption,...

'FontName','Arial','FontWeight','normal',...

'FontSize',12,'Color','blue');

set(gca,'xdir','normal')

set(gca,'ydir','reverse')

axis on;

end

drawnow; % Force display to update.

fprintf('Done!\n');

end

end

hold off

toc

uiwait(msgbox('Execution Ended'));

[muthu A]

Hai , i am a beginner of matlab.I want matlab code for object detection using backgtround subtraction.i have extract frames from video.now i want to detect object from those frames.pls let u know those who have code for this..

[Image Analyst]

muthu, start a brand new question on this and attach two of the frames.

[Mohammedashraf Shaikh]

%%Extracting & Saving of frames from a Video file through Matlab Code%% clc; close all; clear all;

% assigning the name of sample avi file to a variable filename = 'C:\Users\Hp\Desktop\xyz.mp4';

%reading a video file mov = VideoReader(filename);

% Defining Output folder as 'snaps' %opFolder = fullfile(cd, 'SEM-8'); %if not existing %if ~exist(opFolder, 'dir') %make directory & execute as indicated in opfolder variable %mkdir('C:\Users\Hp\Desktop\opFolder'); %end

%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 %indicating the current progress of the file/frame written 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 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 ');

*TILL Now i had this which subtracting two image AND getting foreground By using my code how could i draw Boundary

*by this you can divide video into frame and compare new frame generated to some previous image using subtraction method

but i am not able to draw boundary in video or raise alarm pldease help me if you get *

[Image Analyst]

Simply put hold on, then draw using plot() or rectangle(), then call drawnow.

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

[Mohammedashraf Shaikh]

how to use hold on,plot or rectangle please help me out

[Image Analyst]

hold on;
rectangle(.......whatever, or
plot(............ whatever.

Answer 1

[Image Analyst]

You probably need a "hold on" between these two lines:

rectangle('Position',bb,'EdgeColor','r','LineWidth',2)
plot(bco(1),bco(2),'-m+')

Like this:

rectangle('Position',bb,'EdgeColor','r','LineWidth',2)
hold on;
plot(bco(1),bco(2),'-m+')

[Algorithms Analyst]

Still it is not drawing on detected objects.When I apply frame differencing backgrouns Subtraction it is grawing bounding Box ob detected objects.But when I apply this code on other background subtraction algorithms it is not drawing..can you help to sort out this problem..

[Algorithms Analyst]

How can I convert frame numner in to time format?

[Image Analyst]

Try multiplying by the time between frames.

[Algorithms Analyst]

Ahh..ok I need to try..secondly can you tell me how I compute true positive and true negative for this algorithm is there any function in matlab?I want to measure the F-score for this algorithm.

Thanks

[Image Analyst]

You would have to manually specify that, unless you have a second automated way that you trust that you can use.

[Algorithms Analyst]

Ok thank you I have computed it.I want to control the looping in your frames wrting code as you described here (<http://www.mathworks.co.kr/matlabcentral/answers/57299-adaptive-background-subtraction-algorithm>)

So when I start to write frames into disk the message appear everytime "wrote 1 frames out of 100" "wrote 2 frame out of 100"

I want restrict this message just one time.I mean is this possible to control just poping up one time.e.g

"Wrote 1 frame out of 100". just one time so when done it should say "Wrote 100 frame out of 100".

[Algorithms Analyst]

Here you have write it in loop

for f=1:numberofframes thisframe=read(vid,f); imshow(thisframe);

ProgressIndication=sprintf("wrote frames %d out of ",frame); I wan to control this.

end

Answer 2

[Mohammedashraf Shaikh]

%%Extracting & Saving of frames from a Video file through Matlab Code%% clc; close all; clear all;

% assigning the name of sample avi file to a variable filename = 'C:\Users\Hp\Desktop\xyz.mp4';

%reading a video file mov = VideoReader(filename);

% Defining Output folder as 'snaps' %opFolder = fullfile(cd, 'SEM-8'); %if not existing %if ~exist(opFolder, 'dir') %make directory & execute as indicated in opfolder variable %mkdir('C:\Users\Hp\Desktop\opFolder'); %end

%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 %indicating the current progress of the file/frame written 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 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 ');

*TILL Now i had this which subtracting two image AND getting foreground By using my code how could i draw Boundary