IMAGE PROCESSING TOOLBOX
In
this lab, we have performed some basic image processing exercise by matlab. The
main purpose of this lab is to :
1.
Read and display image
2.
Check how the image appears in the workspace
3.
Perform histogram equalization on the image
4.
Write the image to a disk file
5.
Get information about graphic file
Below is the commands and example output:
>>I
= imread (‘pout2.png’) % Output the
array
>>Imshow(I) % To
display image
 |
| Original 'pout2.png' |
>>whos % To see how I is stored in memory
 |
| Input and output of 'whos' command |
>>figure, imhist(I)
% To display histogram of I in the new figure
 |
| Histogram equilization |
>>I2 = histeq(I) %Equalize
I and output in new array
>>figure, imshow(I2)
%Display the new equalized image I2.
 |
| Equilized 'pout2.png' |
>>imwrite(I2, 'pout2.png') % To write the newly adjusted image I2
back to disk.
>>imfinfo(‘pout2.png’) % To check the content of newly written
file
 |
| Check info |
Next, we also learn on how to edit image
This command shows original image
>> x = imread ('obama.png');
>> figure, imshow (x)
The original image
This command functions to convert original image to be gray scaled:
>> x_g = rgb2gray(x);
>> figure, imshow (x_g)
The image has been converted to gray scale
This command allow cropping image:-
>> imshow (x_g' imcrop);
This command function will flip the image:
>> figure(1); image(x)
x(:, :, 1) = fliplr (x(:, :, 1));
x(:, :, 2) = fliplr (x(:, :, 2));
x(:, :, 3) = fliplr (x(:, :, 3));
figure(2); image(x)
The flipped image
Commands function below will show how an image being flipped vertically and horizontally
>> xMirror = flipdim(x,2); % horizontal flip
>> xUpsideDown = flipdim(x,1); % vertical flip
>> xHorizontalAndVerticalFlip = flipdim (xUpsideDown, 2); % horizontal and vertical flip
>> subplot(2,2,1), imshow(x)
>> subplot(2,2,2), imshow(xMirror)
>> subplot(2,2,3), imshow(xUpsideDown)
>> subplot(2,2,4), imshow(xHorizontalAndVerticalFlip)
Flipped image in both vertical and horizontal
Image info by using command function >> iminfo(x)
