What Is the Image Processing Toolbox?
Configuration Notes
Related Products
Example 1 -- Some Basic Concepts
1. Read and Display an Image
2. Check How the Image Appears in the Workspace
3. Improve Image Contrast
4. Write the Image to a Disk File
5. Check the Contents of the Newly Written File
Example 2 -- Advanced Topics
1. Read and Display an Image
2. Estimate the Value of Background Pixels
3. View the Background Approximation as a Surface
4. Create an Image with a Uniform Background
5. Adjust the Contrast in the Processed Image
6. Create a Binary Version of the Image
7. Determine the Number of Objects in the Image
8. Examine the Label Matrix
9. Display the Label Matrix as a Pseudocolor Indexed Image
10. Measure Object Properties in the Image
11. Compute Statistical Properties of Objects in the Image
Getting Help
Online Help
Image Processing Demos
MATLAB Newsgroup
Image Credits
Examples
Introduction
Images in MATLAB and the Image Processing Toolbox
Image Types in the Toolbox
Binary Images
Indexed Images
Grayscale Images
Truecolor Images
Converting Between Image Types
Color Space Conversions
Converting Between Image Classes
Losing Information in Conversions
Converting Indexed Images
Multiframe Image Arrays
Reading and Writing Image Data
Reading a Graphics Image
Writing a Graphics Image
Querying a Graphics File
Converting Graphics File Formats
Working with DICOM Files
Reading Image Data from a DICOM File
Reading Metadata from a DICOM File
Writing Image Data or Metadata to a DICOM File
Example: Creating a New Series
Image Arithmetic
Image Arithmetic Saturation Rules
Nesting Calls to Image Arithmetic Functions
Coordinate Systems
Pixel Coordinates
Spatial Coordinates
Displaying and Exploring Images
Overview
Understanding Handle Graphics Object Property Settings
Using imshow to Display Images
Specifying the Initial Image Magnification
Controlling the Appearance of the Figure
Using the Image Tool to Explore Images
Opening the Image Tool
Specifying the Initial Image Magnification
Specifying the Colormap
Importing Image Data from the Workspace
Exporting the Image to the Workspace
Closing the Image Tool
Printing the Image in the Image Tool
Using Image Tool Navigation Aids
Overview Navigation
Panning the Image Displayed in the Image Tool
Zooming In and Out on an Image
Specifying the Magnification of the Image
Getting Information about the Pixels in an Image
Determining the Value of Individual Pixels
Getting the Display Range of an Image
Viewing Pixel Values with the Pixel Region Tool
Getting Information About an Image
Adjusting the Contrast and Brightness of an Image
Understanding Contrast Adjustment
Adjusting Contrast and Brightness
Using the Window/Level Tool
Autoscaling
Viewing Multiple Images
Displaying Each Image in a Separate Figure
Displaying Multiple Images in the Same Figure
Displaying Different Image Types
Displaying Indexed Images
Displaying Grayscale Images
Displaying Binary Images
Displaying Truecolor Images
Special Display Techniques
Adding a Colorbar
Displaying All Frames of a Multiframe Image at Once
Converting a Multiframe Image to a Movie
Texture Mapping
Printing Images
Printing and Handle Graphics Object Properties
Setting Toolbox Display Preferences
Toolbox Preferences
Retrieving the Values of Toolbox Preferences
Setting the Values of Toolbox Preferences
Building GUIs with Modular Tools
Overview
Using Modular Tools
Displaying the Target Image
Specifying the Target Image
Specifying the Parent of a Modular Tool
Positioning the Modular Tools in a GUI
Example: Building a Pixel Information GUI
Adding Navigation Aids to a GUI
Making Connections for Interactivity
Creating Your Own Modular Tools
Spatial Transformations
Interpolation
Interpolation Methods
Interpolation and Image Types
Resizing an Image
Specifying the Size of the Output Image
Specifying the Interpolation Method
Using Filters to Prevent Aliasing
Rotating an Image
Specifying the Size of the Output Image
Specifying the Interpolation Method
Cropping an Image
Performing General 2-D Spatial Transformations
Example: Performing a Translation
Defining the Transformation Data
Creating TFORM Structures
Performing the Spatial Transformation
Performing N-Dimensional Spatial Transformations
Example: Performing Image Registration
Step 1: Read in Base and Unregistered Images
Step 2: Display the Unregistered Image
Step 3: Create a TFORM Structure
Step 4: Transform the Unregistered Image
Step 5: Overlay Registered Image Over Base Image
Step 5: Using XData and YData Input Parameters
Step 6: Using XData and YData Output Values
Image Registration
Registering an Image
Point Mapping
Example: Registering to a Digital Orthophoto
Types of Supported Transformations
Selecting Control Points
Using the Control Point Selection Tool
Starting the Control Point Selection Tool
Viewing the Images
Specifying Matching Control Point Pairs
Saving Control Points
Using Correlation to Improve Control Points
Linear Filtering and Filter Design
Linear Filtering
Convolution
Correlation
Filtering Using imfilter
Using Predefined Filter Types
Filter Design
FIR Filters
Frequency Transformation Method
Frequency Sampling Method
Windowing Method
Creating the Desired Frequency Response Matrix
Computing the Frequency Response of a Filter
Transforms
Fourier Transform
Definition of Fourier Transform
Discrete Fourier Transform
Applications of the Fourier Transform
Discrete Cosine Transform
The DCT Transform Matrix
DCT and Image Compression
Radon Transform
Plotting the Radon Transform
Viewing the Radon Transform as an Image
Using the Radon Transform to Detect Lines
Inverse Radon Transform
Example: Reconstructing an Image from Parallel Projection Data
Fan-Beam Projection Data
Computing Fan-Beam Projection Data
Reconstructing an Image from Fan-Beam Projection Data
Working with Fan-Beam Projection Data
Morphological Operations
Dilation and Erosion
Understanding Dilation and Erosion
Structuring Elements
Dilating an Image
Eroding an Image
Combining Dilation and Erosion
Dilation- and Erosion-Based Functions
Morphological Reconstruction
Marker and Mask
Pixel Connectivity
Flood-Fill Operations
Finding Peaks and Valleys
Distance Transform
Objects, Regions, and Feature Measurement
Connected-Component Labeling
Selecting Objects in a Binary Image
Finding the Area of the Foreground of a Binary Image
Finding the Euler Number of a Binary Image
Lookup Table Operations
Analyzing and Enhancing Images
Getting Information about Pixel Values and Statistics
Getting Information About Image Pixels
Getting the Intensity Profile of an Image
Displaying a Contour Plot of Image Data
Creating an Image Histogram
Getting Summary Statistics About an Image
Computing Properties for Image Regions
Analyzing an Image
Detecting Edges
Tracing Boundaries
Detecting Lines Using the Hough Transform
Using Quadtree Decomposition
Analyzing the Texture of an Image
Using Texture Filter Functions
Using a Gray-Level Co-Occurrence Matrix (GLCM)
Intensity Adjustment
Adjusting Intensity Values to a Specified Range
Histogram Equalization
Contrast-Limited Adaptive Histogram Equalization
Decorrelation Stretching
Noise Removal
Using Linear Filtering
Using Median Filtering
Using Adaptive Filtering
Region-Based Processing
Specifying a Region of Interest
Selecting a Polygon
Other Selection Methods
Filtering a Region
Example: Filtering a Region in an Image
Specifying the Filtering Operation
Filling a Region
Image Deblurring
Understanding Deblurring
Causes of Blurring
Deblurring Model
Using the Deblurring Functions
Deblurring with the Wiener Filter
Deblurring with a Regularized Filter
Deblurring with the Lucy-Richardson Algorithm
Deblurring with the Blind Deconvolution Algorithm
Creating Your Own Deblurring Functions
Avoiding Ringing in Deblurred Images
Color
Working with Different Screen Bit Depths
Determining Screen Bit Depth
Choosing a Screen Bit Depth
Reducing the Number of Colors in an Image
Color Approximation
Reducing Colors in an Indexed Image
Dithering
Converting Color Data Between Color Spaces
Converting Between Device-Independent Color Spaces
Performing Profile-Based Conversions
Converting Between Device-Dependent Color Spaces
Neighborhood and Block Operations
Block Processing Operations
Types of Block Processing Operations
Sliding Neighborhood Operations
Padding Borders
Linear and Nonlinear Filtering
Distinct Block Operations
Overlap
Column Processing
Sliding Neighborhoods
Distinct Blocks
Functions -- Categorical List
Image Input, Output, and Display
Modular Interactive Tools
Spatial Transformation and Registration
Image Analysis and Statistics
Image Arithmetic
Image Enhancement and Restoration
Linear Filtering and Transforms
Morphological Operations
Region-Based, Neighborhood, and Block Processing
Colormap and Color Space Functions
Miscellaneous Functions
Functions -- Alphabetical List
Printable Documentation (PDF)
Product Page (Web)