REport - EE440
Dang Tran Chi Toan 10ECE DUTReport EE440
1. Read image with Matlab[footnoteRef:1] [1: The students are
required to submit the Matlab codes for these exercises.]
a. Load the image lena512.bmp, using imread(), and show it using
imshow().lena512 = imread('lena512.bmp');imshow(lena512);
b. Get the type of the loaded image data (Use MATLAB function
class()), and get the maximum and minimum data value for this
imageclass(lena512) % uint8 max(max(lena512)) %
245min(min(lena512,[],1)) % 25
c. Convert the data to double type (use MATLAB function
double()), show the double-typed image using imshow()D_lena512 =
double(lena512);figure;imshow(D_lena512);
d. Is the result from c correct? If not, how do you think you
can correct it?D_lena512 =
double(lena512);figure;imshow(D_lena512,[]);
2. Color image and manipulationa. Load and show the image
LightHouse_color.pnglighthouse =
imread('kodim19.png');imshow(lighthouse);
b. Show three plans R, G, B of this imageR = lighthouse(:,:,1);B
= lighthouse(:,:,2);G =
lighthouse(:,:,3);figure;subplot(141);imshow(R);subplot(142);imshow(B);subplot(143);imshow(G);
REDBLUEGREEN
c. Convert this color image to a grayscale image using rgb2gray.
Display the resultGray_lighthouse =
rgb2gray(lighthouse);figure;imshow(Gray_lighthouse);
d. Crop and show a patch (subimage) from this color image (Hint:
get a submatrix using M(row1:row2, col1:col2))
imshow(lighthouse(3:200,3:200,:));
e. Divide this color image into 16 equal blocks. Place the
blocks in the reverse order as below. Show the resulting color
image Before After
h = size(lighthouse,1);w = size(lighthouse,2);d =
size(lighthouse,3);hi = h/4;wi = w/4;newlighthouse = zeros
(h,w,d,'uint8');for i = 1:4 for k = 1:4 x = ((i-1)*hi+1):i*hi; y =
((k-1)*wi+1):k*wi; a = ((4-i)*hi+1):(5-i)*hi; b =
((4-k)*wi+1):(5-k)*wi; newlighthouse(x,y,1:d) = lighthouse(a ,b
,1:d);
endendfigure;subplot(121);imshow(lighthouse);subplot(122);imshow(newlighthouse);
3. Write an imagea. Reload the image LightHouse_color.png from
exercise 2
RGBlighthouse = imread('kodim19.png');
b. Exchange the plans R and G of this image, show the resulting
image
h = size(RGBlighthouse,1);w = size(RGBlighthouse,2);d =
size(RGBlighthouse,3);GRBlighthouse =
zeros(h,w,d,'uint8');GRBlighthouse(1:h,1:w,1) =
RGBlighthouse(1:h,1:w,2);GRBlighthouse(1:h,1:w,2) =
RGBlighthouse(1:h,1:w,1);GRBlighthouse(1:h,1:w,3) =
RGBlighthouse(1:h,1:w,3);subplot(121);imshow(RGBlighthouse);subplot(122);imshow(GRBlighthouse);
c. Using imwrite to generate an image file for this new color
image (for example bmp file). Check on your computer whether it is
correct. imwrite(GRBlighthouse,'GRBlighthouse.bmp');
4. Read a video with Matlab[footnoteRef:2] [2: For bonus
points]
a. Choose a video (for example an .avi file) from your computer
or Internetb. Using VideoReader to load this video
video =
VideoReader('Monsters.University.2013.720p.BluRay.x264.YIFY.mp4')
% Summary of Multimedia Reader Object for
'Monsters.University.2013.720p.BluRay.x264.YIFY.mp4'.% Video
Parameters: 23.98 frames per second, RGB24 1280x720.% 149314 total
video frames available.
c. Show this video and report some
framessubplot(331);imshow(read(video,100));subplot(332);imshow(read(video,200));subplot(333);imshow(read(video,300));subplot(334);imshow(read(video,400));subplot(335);imshow(read(video,500));subplot(336);imshow(read(video,600));subplot(337);imshow(read(video,700));subplot(338);imshow(read(video,800));subplot(339);imshow(read(video,900));
5. Image rotationa. Load a grayscale image image =
imread(lena512.bmp);
b. Use imrotate to rotate this image with 45, and then with
90image45 = imrotate(image,45);image90 = imrotate(image,90);
c. Show the original image and the rotated image in the same
figure (using
subplot)subplot(131);imshow(image);subplot(132);imshow(image45);subplot(133);imshow(image90);
d. Write a program to carry out the rotation of an image, i.e.
do not use the function imrotate. Compare with the results from
question b.image=imread(lena512.bmp); %image padding[Rows, Cols,
Dim] = size(image); Diagonal = sqrt(Rows^2 + Cols^2); RowPad =
ceil(Diagonal Rows) + 2;ColPad = ceil(Diagonal Cols) + 2;imagepad =
zeros(Rows+RowPad,
Cols+ColPad);imagepad(ceil(RowPad/2)ceil(RowPad/2)+Rows-1),ceil(ColPad/2)
ceil(ColPad/2)+Cols-1)) = image; degree=45;rads =
pi*(degree/180);%midpointsmidx=ceil((size(imagepad,1)+1)/2);midy=ceil((size(imagepad,2)+1)/2);
imagerot=zeros(size(imagepad)); %rotationfor i=1:size(imagerot,1)
for j=1:size(imagerot,2) x= (i-midx)*cos(rads)+(j-midy)*sin(rads);
y=-(i-midx)*sin(rads)+(j-midy)*cos(rads); x=round(x)+midx;
y=round(y)+midy; if (x>=1 && y>=1 && x
