Graphics

Overview

MATLAB provides commands for reading, writing, and displaying several types of graphics file formats for images. As with MATLAB-generated images, once a graphics file format image is displayed, it becomes a Handle Graphics image object. MATLAB supports the following graphics file formats:

• BMP (Microsoft Windows Bitmap)
• HDF (Hierarchical Data Format)
• JPEG (Joint Photographic Experts Group)
• PCX (Paintbrush)
• PNG (Portable Network Graphics)
• TIFF (Tagged Image File Format)
• XWD (X Window Dump)

For information concerning the bit depths and image types supported for these formats, see imread and imwrite.

MATLAB supports three different numeric classes for image display: double-precision floating-point (double), 16-bit unsigned integer (uint16), and 8-bit unsigned integer (uint8). The image display commands interpret data values differently depending on the numeric class the data is stored in.

This chapter discusses the different data and image types you can use, and includes details on how to: read, write, work with, and display graphics images; how to alter the display properties and aspect ratio of an image during display; how to print an image; and how to convert the data type or graphics format of an image.

This table lists the functions discussed in this chapter.

Function	Purpose	Function Group
axis	Plot axis scaling and appearance	Display
image	Display image (create image object)	Display
imagesc	Scale data and display as image	Display
imread	Read image from graphics file	File I/O
imwrite	Write image to graphics file	File I/O
imfinfo	Get image information from graphics file	Utility
ind2rgb	Convert indexed image to RGB image	Utility

Displaying Bit-Mapped Images

Images in MATLAB