EE440 Lab 1 Report
Names: Huynh Nhu Kien Ha Xuan Cuong Nguyen Phuc Bao HungClass:
10ECE
1/ Linear stretching:Code:%-----------linear
stretching----------im = imread('3_1.jpg'); % Read image%
im=imread('3_2.jpg');subplot(221);imshow(im),title('Original
Image'); % Display the imagehsv= rgb2hsv(im); % Convert the image
from RGB colormap to HSV colormapV= hsv(:,:,3); % Assign the
intensity of the HSV image to
Vsubplot(222),imhist(V),title('Histogram of the Intensity');V=
uint8(255*(V-min(V(:)))/(max(V(:))-min(V(:)))); % Algorithm and
scale % the Intensity from [0 1] to [0 255]V=double(V)/255; %
Rescale the Intensity back to [0 1]hsv(:,:,3)=V; % Reassign V
intonewIm= hsv2rgb(hsv); % Convert the image back to RGB
colormapsubplot(223);imshow(newIm),title('Stretched
Image');subplot(224),imhist(V),title('Histogram of new Image
Intensity');
2/ Histogram Equalization:Code:%------------ Histogram
equalization---------------im=imread('3_1.jpg');%
im=imread('3_2.jpg');hsv=rgb2hsv(im); % Convert the image to HSV
colormapV=hsv(:,:,3); % Assign the Intensity of the image to
VV=uint8(255*V); % Scale the intensity from [0 1] to [0
255][nk,x]=imhist(V);subplot(221);imhist(V),title('Histogram of the
intensity');subplot(222);imshow(im),title('Original
Image');MN=numel(V); % number of elements in
Vsk=round(255/MN*(cumsum(nk))); % Calculate the cdf of Vfor i=1:MN
for j=1:256 if(V(i)==j) V(i)=sk(j); % Replace each Intensity value
with a new one after % taking cumulative sum algorithm break end
endendsubplot(223);imhist(V),title('Histogram of new Image
Intensity');V=double(V)/255; % Convert the Intensity back to scale
[0 1]hsv(:,:,3)=V; % Reassign the Intensity to the HSV
imageNewIm=hsv2rgb(hsv); % Convert the HSV image to RGB
imagesubplot(224);imshow(NewIm),title('Equalized Image');
3/ Histogram Matching:Code:clc; clear;%----------------choose an
image to enhance--------------------------
input=imread('3_1.jpg');% input=imread('3_2.jpg');
%----------------histogram
specification----------------------------
hsv=rgb2hsv(input);V=hsv(:,:,3);NV=uint8(255*V);V=uint8(255*V);[nk,x]=imhist(V);
% original histogramMN=numel(V); % number of values in
Vsk=round(255/MN*(cumsum(nk))); % transformation function
skz=0:1:255;d=normpdf(z,100,60); % desired
histogramgz=round(255*(cumsum(d))); % transformation function G(z)
% r to sfor i=1:MN for j=1:256 if(V(i)==(j-1)) V(i)=sk(j); break
end endend% s to zfor i=1:MN j=1; if(V(i)gz(j)&&j
