This help is just for you to start the assignment.  

Q1. In Matlab workspace, read, display and get properties of the images cameraman.tif and lena_grey.tif.

1. Use the imfinfo, imread, imshow, whos, size, and display the two images in one row in a figure window.   
   
   - create an assignment folder, say a1
   - download the two images and save them to the folder a1
   - start Matlab, then do a self-tutorial using an online tutirial if you never used Matlab before
   - change the current working directory to a1
   -  try the following commands
   
   >>  imfinfo('cameraman.tif')
   >> imshow('cameraman.tif')
   >> f = imread('cameraman.tif');      % use ; r
   >> size(f)
   >> imshow(f)
   >> whos f
   >> subplot(1, 2, 1), imshow(f)
   >> subplot(1, 2, 2), imshow('lena_grey.tif')
   
   do more practices on matrix to find the mean and Std
   
   mean2(f)
   std2(f)
   　
   
   
2. Examine the image properties of the two images and supply the requested data below.
   
   from the above operations, fill the following tables for both images
   
                   cameraman.tip     lena_grey.tif   
   Width             256                 ??
   Height            256                 ??   
   Color depth                  ??                                    ??
   File size                        ??                  ??
   Image color type   ??                 ?? 
   Mean pixel value  ??                 ??
   Std. deviation    ??                 ??
   
   

Q2. Write a Matlab m file to load the image autumn.tif and then save the image file in the following format.

.tiff Tagged Image File Format (or .tif)
.jpeg Joint Photographic Experts Group (or .jpg)
.bmp Windows Bitmap

name you m file as a1q2.m

>> edit a1q2.m

in the m file you can

function a1q2(filename)

img = imread(filename);
imwrite(......);     % you can use file name  like a1q2.tif, etc
...
...
...
make sure that the file you created can be open.

Q3. Write an m files to do the following:

1. create a black and white image of size 512 x 512 with a square of edge length 200 in the middle, and save the image as sqaure.gif
   
2. read the above the square.tif image and rotate image 45 degree anti-clockwise and then scale the square by a factor of 1.414 (with respect to the center of the square). then add the two images together, save the image to the file nested_squares.gif
   
   
   function a1q3()
   
   %s1   - subquestion 1
   img = uint8(ones(512,512)*255);   % 8 bits, unsigned data type, this is to create a while image
   for i=1:1:200
   .....  % change the pixel value at the square position to be 0, (black)
   end
   imshow( );   % testing
   imwrite(... );
   
   %s2
   
   img = imread(... );
   dim = size(img);
   img2 = uint8(ones(dim));  % to hold the transformed image
   img3 = img;   % to hold the final resuluting image
   for i=1:1:dim(1)
      for j=1:1:dim(2)
           if (img(i,j) == 0)   % only transform those white points, you need to translate the square to the origin before scaling, and translate back after rotation.
                ....
           end
      end
   end
   
   imshow(img3);
   imwrite(.......);
   
   
   
   
3. You can also write an m file to create your own art image.
   

Q4. Write a function that converts the RGB values to grayscale values by forming the following standard weighted sum of the R, G, and B components: 0.2989 * R + 0.5870 * G + 0.1140 * B.  The function has calling prototype [grayimage_out] = rgbtograyscale(rgbimage_in). Testing your function by autumn.tif

function temp = rgbtograyscale(filename)
img = imread(filename);

......

dim = size(img);
 ...  

temp = uint8(zeros(size(1), size(2)))

.........

imshow(temp);   
   

Q5. Write a Matlab function to convert an image into a binary image using by thresholding m. Use function prototype  convert2binary('image_name', m) .  Test your program using this image with m = 128.


function convery2binary(filename, m)
img=imread(filename);
....
imshow(img);
imwrite(....);

Q6. 

function instensitySpread(filename,lmin,lmax)
img=imread(filename);
fmin=min(img(:));
fmax=max(img(:)); 

r=double(lmax-lmin)/double(fmax-fmin);

img(i,j)=.....

imshow(img);
imwrite(img,'q6.tif');

mask of size m can be coreated by

w=zeros(m,m);
m = m-1;
for i=-m/2:+m/2
    for j=-m/2:+m/2
        w(i+m/2+1,j+m/2+1)=gauss(i,j,1);
    end
end

Q10.