i have code for extracting multiple faces from an image and cropping these extracted faces from image, now i want to save these cropped faces in a folder , how can i do that??

clc;

 I=imread('E:/g.jpg');

    figure(1),imshow(I);
    FaceDetect = vision.CascadeObjectDetector; 
    BB = step(FaceDetect,I);
     figure(2),imshow(I);

 for i = 1:size(BB,1)
    rectangle('Position',BB(i,:),'LineWidth',3,'LineStyle','-  ','EdgeColor','r');
 end
 for i = 1:size(BB,1)
 J= imcrop(I,BB(i,:));
 figure(3),subplot(5,5,i);imshow(J);

 end

Answer 1

[Cam Salzberger]

Hello Saeeda,

You can use imwrite to save images to a file.

imwrite(J, 'E:\g_cropped.jpg')

-Cam

[saeeda saher]

 *
I am applying this but it saves only one cropped image, not the all cropped faces.. how to save all of them??*
clc;

 I=imread('E:\g.jpg');

    figure(1),imshow(I);
    FaceDetect = vision.CascadeObjectDetector; 
    BB = step(FaceDetect,I);
     figure(2),imshow(I);

 for i = 1:size(BB,1)
    rectangle('Position',BB(i,:),'LineWidth',3,'LineStyle','-  ','EdgeColor','r');
 end
 for i = 1:size(BB,1)
 J= imcrop(I,BB(i,:));
 figure(3),subplot(5,5,i);imshow(J);
  imwrite(J, 'E:\g_cropped.jpg')
 end

[Cam Salzberger]

Since you are calling imwrite in a for loop, it is actually saving each of the different J values. However, you have it saving to the same filename each time. I assumed that you would want your own naming convention, and could add that. Something like:

fname = sprintf('g_cropped_%d.jpg', i);
fpath = fullfile('E:', fname);
imwrite(J, fpath)

You can customize the name and path or anything you feel like as you like. This is just for illustration purposes.

-Cam

[saeeda saher]

its great thanks :)

[saeeda saher]

i want to apply facial expression recognition on the cropped images. kindly, guide me.

[Cam Salzberger]

That is not an easy problem that someone can simply "guide you" through. There are actually challenges where people can win money for solving that kind of problem.

There are some suggested products and workflows on the MathWorks site, but it will require significant amount of data (classified images) to start with as a baseline. Depending on how you define your problem, you may be able to find papers/work done by others on this problem to advance you further, or you may have to do the majority of it yourself. But either way, I'd start with some scholarly article review.