Matlab Tutorials

Working with 8-Bit and 16-Bit Images

8-Bit and 16-Bit Indexed Images

Double-precision (64-bit) floating-point numbers are the default MATLAB representation for numeric data. However, to reduce memory requirements for working with images, you can store images as 8-bit or 16-bit unsigned integers using the numeric classes uint8 or uint16, respectively. An image whose data matrix has class uint8 is called an 8-bit image; an image whose data matrix has class uint16 is called a 16-bit image. Read More

Matlab Image Types

Indexed Images

An indexed image consists of a data matrix, X, and a colormap matrix, map. map is an m-by-3 array of class double containing floating-point values in the range [0, 1]. Each row of map specifies the red, green, and blue components of a single color. An indexed image uses “direct mapping” of pixel values to colormap values. The color of each image pixel is determined by using the corresponding value of X as an index into map. Values of X therefore must be integers. The value 1 points to the first row in map, the value 2 points to the second row, and so on. Display an indexed image with the statements Read More

Working with Images in MATLAB Graphics

What Is Image Data?

The basic MATLAB data structure is the array, an ordered set of real or complex elements. An array is naturally suited to the representation of images, real-valued, ordered sets of color or intensity data. (An array is suited for complex-valued images.) Read More

Displaying Graphics Images

Image Types and Display Methods

To display a graphics file image, use either image or imagesc. For example, assuming RGB is an image, Read More

Reading, Writing, and Querying Graphics Image Files

Working with Image Formats

In its native form, a graphics file format image is not stored as a MATLAB matrix, or even necessarily as a matrix. Most graphics files begin with a header containing format-specific information tags, and continue with bitmap data that can be read as a continuous stream. For this reason, you cannot use the standard MATLAB I/O commands load and save to read and write a graphics file format image. Read More

Matlab Core Graphics Objects

Core graphics objects include basic drawing primitives: Read More