I want to make a background black and foreground is same as original.

O=imread('wed.jpg');
figure,imshow(O);
whos O

C=rgb2gray(O);
figure,imshow(C);

b=C > 128;

whos b

[m n]=size(b)
 for i=1:m
     for j=1:n
         if (b(i,j)==1)
     bIn3Dims(i,j,:)= O(i,j,:)
 
         end
     end
 end
  figure,imshow(b)

Answer 1

[Puru Kathuria]

Hi,

You can try activecontour and lazysnapping. Both of them are for segmenting image into background and foreground using contours and graph-based segmenting respectively.

Also have a look at this Image Segmentation Tutorial.

References/Citations:

Image Analyst (2020). Image Segmentation Tutorial, MATLAB Central File Exchange. Retrieved July 22, 2020.