How does Imread work in MATLAB?

The imread function in MATLAB reads an image file and stores it as a numerical array. It interprets the image data based on the file format and returns a multidimensional array representing the image.

Understanding the Process

• File Reading: The function first opens the specified image file.
• Data Extraction: It then reads the image data, which can be in various formats like JPEG, PNG, TIFF, etc.
• Array Conversion: The extracted data is converted into a multidimensional array, where each dimension represents a different aspect of the image.
  • For grayscale images, the array has two dimensions: rows and columns. Each element represents the pixel intensity.
  • For color images, the array has three dimensions: rows, columns, and color channels (typically Red, Green, Blue). Each element represents the pixel intensity for a specific color channel.
• Output: The imread function returns the multidimensional array representing the image. You can then use this array to display, manipulate, or analyze the image in MATLAB.

Example

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

% Display the image
imshow(image);

This code reads a JPEG image named "my_image.jpg" and displays it using the imshow function.

Practical Insights

• imread can handle a wide range of image formats.
• You can specify the image format explicitly using the second input argument, e.g., imread('my_image.jpg', 'jpg').
• The returned array's size and data type depend on the image format and content.