Labeling object in a binary image MATLAB

Question

I am trying to label white objects in a binary image using MATLAB. Basically, my aim is to detect water bodies in a aerial map image and then convert the cimage to binary and then label the bodies. Here is an image example of my output after detecting the bodies and converting to binary. How can I now possibly create a create rectangle around the white objects and label them with text(using connected components)? Thank you!

enter image description here

Do you have the Image Processing Toolbox? If so, look into regionprops that can return the bounding boxes — Cape Code
Yeas I have the image processing toolbox. I was looking into that, just could not figure out how to use it. — lucky88shp

Divakar Divakar · Accepted Answer · 2014-03-24T19:54:37

Try this -

%%// Read in the image file
img = im2bw(imread(FILE));

%%// Get bounding box stats
stats = regionprops(bwlabel(img),'Area','Centroid','Perimeter','BoundingBox');
Boxes=cat(1,stats.BoundingBox);

%%// Placeholder to store the final result
maskm = false(size(img,1),size(img,2));

for k1 = 1:size(Boxes,1)

    %%// Initialize a mask representing each bounding box
    mask1 = false(size(img,1),size(img,2));

    %%// Get the coordinates of the boxes
    starty = round(Boxes(k1,1));
    stopy = starty+round(Boxes(k1,3))-1;
    startx = round(Boxes(k1,2));
    stopx = startx+round(Boxes(k1,4))-1;

    %%// Finaly create the mask
    mask1(startx:stopx,starty:stopy) = true;
    maskm = maskm + imdilate(edge(mask1,'sobel'),strel('disk',2));
end

%%// Get the boxes around the original blobs
maskm = maskm + img;
figure,imshow(maskm);

Output

enter image description here

Look into text on how to label the boxes.

Labeling object in a binary image MATLAB

1 Answers