BoundingBox in selected object

I have a binary image with 5 objects

I want to draw a boundingbox only in the 3rd object (from the left).How can I do that by using regionprops. I have attached the image. The size and shape of the objects are same.

Answer 1

[Sourabh]

Hey @rupam baruah

You can draw a boundingbox on the 3rd object from the left using “regionprops” as follows:

1. Ensure the image is 2D binary grayscale

bw = imbinarize(rgb2gray(img)); 

2. Get properties of each region

stats = regionprops(bw, 'BoundingBox', 'Centroid'); 

3. Get the bounding box of the 3rd object from the left

boundingBox = stats(3).BoundingBox; 

4. Display the image and the bounding box

imshow(bw); 
hold on; 
rectangle('Position', boundingBox, 'EdgeColor', 'r', 'LineWidth', 2); 
hold off; 

The final output looks like this:

For more related examples on using “regionprops”, kindly follow the MATLAB documentation:

https://www.mathworks.com/help/images/ref/regionprops.html