【Advanced】Basic Image Processing in MATLAB: Reading, Displaying, and Saving Images

# [Advanced Series] Basic Image Processing in MATLAB: Reading, Displaying, and Saving Images

## 1. Introduction to MATLAB Image Processing

MATLAB is a powerful technical computing language widely used in the field of image processing. It offers a rich library of functions and toolboxes that make image processing tasks more efficient and convenient. Image processing involves manipulating digital images to enhance, analyze, and extract valuable information. MATLAB has several advantages in image processing:

- **Rich Function Library:** MATLAB provides a vast array of image processing functions that cover every aspect of image reading, displaying, transforming, enhancing, segmenting, and analyzing. These functions are optimized to efficiently process large-scale image data.
- **Intuitive Syntax:** MATLAB employs intuitive syntax, making image processing code easy to write and understand. This allows developers to quickly implement complex image processing algorithms.
- **Powerful Visualization Tools:** MATLAB offers robust visualization tools such as `imshow()` and `subplot()`, enabling image processing results to be presented intuitively. This aids users in understanding the image processing workflow and evaluating outcomes.

## 2. Image Reading, Displaying, and Saving

### 2.1 Image Reading Methods

#### 2.1.1 `imread()` Function

The `imread()` function is the standard function in MATLAB for reading image files. It takes the image file path as input and returns the image data as output. Image data is a three-dimensional array where the first two dimensions represent the height and width of the image, and the third dimension represents the number of color channels.

% Read the image file
image = imread('image.jpg');

% Check the image size
size(image)

% Check the number of color channels
ndims(image)

#### 2.1.2 `imfinfo()` Function

The `imfinfo()` function provides information about an image file, including the file format, dimensions, number of channels, and color space. It takes the image file path as input and returns a structure containing the image file's metadata.

% Get information about the image file
info = imfinfo('image.jpg');

% Check the image file format
info.Format

% Check the image dimensions
info.Height
info.Width

% Check the number of channels
info.NumComponents

### 2.2 Tips for Image Display

#### 2.2.1 `imshow()` Function

The `imshow()` function is used for displaying images. It takes image data as input and displays the image in the current figure window.

% Display the image
imshow(image);

#### 2.2.2 `subplot()` Function

The `subplot()` function is used to create subplots to display multiple images within the same figure window. It takes the position and size of the subplot as input and creates a subplot at the specified position.

% Create subplots
subplot(2, 2, 1);
imshow(image1);

subplot(2, 2, 2);
imshow(image2);

subplot(2, 2, 3);
imshow(image3);

subplot(2, 2, 4)