imcrop a specific bounding box

Hi, I am trying to write code that will crop around a specific bounding box on appdesigner. It currently works when there is only a single bounding box in the image. However when there are several it wouldn't know which box to crop around.

This is the current code.

bboxes = step(faceDetector, faceimage);

CroppedFaces = imcrop(app.Faces,bboxes);

Thank you

[Chaitanya Mallela]

if the faceDetector object has Bounding Box property, try to Label every Bounding Box and execute imcrop command in a loop whose max iteration value equals Number of Labels.

Answer 1

[Josep Llobet]

You can try the next code:

Obtain the image example

% __JUST OBTAIN THE IMAGE__%
% Obtain image
krillin = imread("https://es.mathworks.com/responsive_image/150/150/0/0/0/cache/matlabcentral/profiles/22817879_1627284404454.jpg");
% Process it
krillin_grey = im2gray(krillin);
krillin_grey_imadj = imadjust(krillin_grey);
krillin_BW = imbinarize(krillin_grey_imadj);
krillin_BW_2 = imclearborder(~krillin_BW);

% Labels (not necessary)
% krillin_BW_2_bwlab = bwlabel(krillin_BW_2);
% unique(krillin_BW_2_bwlab(:))
% imshow(krillin_BW_2_bwlab, [])

% Obtain the three major objects
krillin_BW_2_largest = bwpropfilt(krillin_BW_2, "Area", 3, "largest");
imshow(krillin_BW_2_largest)

Crop the Bounding Boxes

% __CROP THE BOUNDING BOXES__%
BB = regionprops(krillin_BW_2_largest,'BoundingBox');  %<--- rellevant

for every_BB = 1:length(BB)
    BB(every_BB).BoundingBox;
    krillin_BW_BB = imcrop(krillin, BB(every_BB).BoundingBox+[-1 -1 1 1]);        %Es retalla la imatge basant-se amb el BoundingBox.
    % change v'krillin' for v'krillin_BW_2_largest' for obtain the binary images of bounding box
    figure
    imshow(krillin_BW_BB)
end

From the image: you must obtain: