how to draw a BoundingBox

Hello. Can someone help me please ? I'm just starting in programation. I found a code that can detect edges, and i want to draw a bounding boxes arround the detected edges.

if true
    close all;clear all;clc
vid = VideoReader ('F:\TRAIT IMG\DETECTION\vol_drone.mp4');
k = vid.NumberOfFrames;
for i=1:k
    J=read(vid,i);
    %imshow(rgb2gray(J));

%J = imread('drone.jpg');
I = rgb2gray(J);
% imshow(I), title('image original grisé');
[~, threshold] = edge(I, 'sobel');
fudgeFactor = .5;
BWs = edge(I,'sobel', threshold * fudgeFactor);
figure, imshow(BWs), title('binary gradient mask');
se90 = strel('line', 3, 90);
se0 = strel('line', 3, 0);
BWsdil = imdilate(BWs, [se90 se0]);
figure, imshow(BWsdil), title('dilated gradient mask');
BWdfill = imfill(BWsdil, 'holes');
figure, imshow(BWdfill);
title('binary image with filled holes');
BWnobord = imclearborder(BWdfill, 4);

figure, imshow(BWnobord), title('cleared border image');
seD = strel('diamond',1);
BWfinal = imerode(BWnobord,seD);
BWfinal = imerode(BWfinal,seD);
figure, imshow(BWfinal), title('segmented image');
BWoutline = bwperim(BWfinal);
Segout = J; 
Segout(BWoutline) = 255; 
figure, 
imshow(Segout), title('outlined original image');

end
  end

Answer 1

[Marek Balaz]

Hello,

I'm not sure in what state are your images after image preprocessing but this is what I used in similar problem with drawing bounding boxes.

imshow(YOUR_IMAGE);
hold on;
labeledImage = logical(YOUR_BINARY_IMAGE); %not needed, image should be already in logical
measurements = regionprops(labeledImage, 'BoundingBox');
for k = 1 : length(measurements)
    thisBB = measurements(k).BoundingBox;
    rectangle('Position',[thisBB(1),thisBB(2),thisBB(3),thisBB(4)],'EdgeColor','b','LineWidth',1 );
end

[Image Analyst]

I think you meant

labeledImage = bwlabel(YOUR_BINARY_IMAGE);

[Marek Balaz]

Hello Image Analyst,

No, I didn't. Here is MATLAB Explanation:

Code Analyzer has found a call of regionprops with a first argument that is a call to bwlabel. In many cases, the argument of bwlabel is a logical matrix, or you can convert it to one. Beginning in MATLAB Version 7.8 (release R2009a), you can pass this logical matrix directly to regionprops without the call to bwlabel. This is faster and uses less space than the previous method.