实验要求：
Zooming and Shrinking Images by Pixel Replication
Objective
To manipulate a technique of zooming and shrinking images by pixel replication.
Main requirements: Ability of programming with C, C++, or Matlab.
Instruction manual:
(a) Write a computer program capable of zooming and shrinking an image by pixel replication. Assume that the desired zoom/shrink factors are integers. You may ignore aliasing effects. You will need to download Fig. 2.19(a).
(b) Download Fig. 2.19 (a) and use your program to shrink the image from 1024 x 1024 to 256 x 256 pixels.
(c) Use your program to zoom the image in (b) back to 1024 x 1024. Explain the reasons for their differences.
实验目的就是通过编程对图像大小进行放大或缩小。
上代码：
%%
clear all;
clc;
close all;
%%
% 1024*1024 to 256*256 shrink;
img_name = 'general_img_1024.jpg';
img = imread(img_name);
img1 = imresize(img, [256, 256]);
figure(1)
imshow(img);
title('1024 * 1024');
figure(2)
imshow(img1);
title('256 * 256');
imwrite(img1,'general_img_shrinked.jpg');
% 256 * 256 to 1024 * 1024 zoom；
img_name = 'general_img_shrinked.jpg'
img2 = imread(img_name);
img3 = imresize(img, [1024, 1024]);
figure(3)
imshow(img3);
title('1024 * 1024');
imwrite(img3,'general_img_zoomed.jpg');程序中主要调用了MATLAB中的 imresize 这个函数对图像大小进行缩放。
实验结果：
