smoothing and Connected region

how can i smoothing image for done by filling up the small regions and dilating the boundary of the thresholded image and Connected region using the 8-neighbor pattern?

clear all;

close all;

clc

bitmap=uigetfile('*.*');

I = imread(bitmap);

imshow(I)

H = rgb2hsv(I)

R=I(:,:,1)

G=I(:,:,2)

B=I(:,:,3)

h=H(:,:,1)

s=H(:,:,2)

v=H(:,:,3)

VH=v-h

VHV=VH-v

VHVVH=VHV-VH

figure,

subplot(4,4,1),imshow(I); title('RGB IMAGE')

subplot(4,4,2),imshow(B); title('R ')

subplot(4,4,3),imshow(G); title('G ')

subplot(4,4,4),imshow(B); title('B ')

figure

subplot(3,3,1),imshow(H); title('hsv IMAGE')

subplot(3,3,2),imshow(h); title('h')

subplot(3,3,3),imshow(s); title('s ')

subplot(3,3,4),imshow(v); title('v ')

subplot(3,3,5),imshow(VH); title('vh ')

subplot(3,3,6),imshow(VHV); title('vhv ')

subplot(3,3,7),imshow(VHVVH); title('VHVVH ')

% Thresholding

j = rgb2gray(I)

figure,imshow(j)

level = 0.5

BW = imbinarize(j,level);

figure,imshow(BW)

figure,imshowpair(j,BW,'montage')

[magramane khadidja]

@Image Analyst