I want to draw a boundary around the bubble shown in the image.

 I cannot use bwboundaries, because it is not able to distinguish the bubble from the rest of the image. Please provide me a method to find the boundary of this bubble.

Answer 1

[Hardik Madhok]

clear all close all clc

img = imread('Test.jpg'); figure imshow (img); drawnow

img = rgb2gray(img); img_1 = histeq(img); img_2 = im2bw(img_1); figure imshow (img_2) drawnow

[B,L,N] = bwboundaries(img_2) imshow(img_2); hold on; for k=1:length(B), boundary = B{k}; if(k > N) plot(boundary(:,2), boundary(:,1), 'g','LineWidth',2); else plot(boundary(:,2), boundary(:,1), 'r','LineWidth',2); end end

try this i am not sure about which bubble you want to extract but this code makes all the boundaries do check and delete the unwanted areas