07-08-2012, 03:02 PM
Image Processing Using Matlab
Image Processing Using Matlab.ppt.ppt (Size: 669 KB / Downloads: 43)
What is the Image Processing Toolbox?
The Image Processing Toolbox is a collection of functions that extend the capability of the MATLAB ® numeric computing environment.
Many of the toolbox functions are MATLAB M-files, series of MATLAB statements that implement specialized image processing algorithms.
Geometric operations
Neighborhood and block operations
Linear filtering and filter design
Transforms
Image analysis and enhancement
Binary image operations
Region of interest operations
IP Toolbox
You can view the MATLAB code for these functions using the statement:
type function_name
You can extend the capabilities of the Image Processing Toolbox by writing your own M-files, or by using the toolbox in combination with with other toolboxes, such as the Signal Processing Toolbox and the Wavelet Toolbox.
Images in the Image Processing Toolbox
The basic data structure in MATLAB is the array, an ordered set of real or complex elements.
MATLAB stores most images as two-dimensional arrays (i.e., matrices), in which each element of the matrix corresponds to a single pixel in the displayed image.
For example, you can select a single pixel from an image matrix using normal matrix subscripting:
I(2,15)
Data Types Continued
In order to reduce memory requirements, MATLAB supports storing image data in arrays of class uint8. The data in these arrays is stored as 8-bit unsigned integers. Data stored in uint8 arrays requires one eighth as much memory as data in double arrays. (Noninteger values cannot be stored in uint8 arrays, for example, but they can be stored in double arrays.)
RGB Images
In MATLAB, the red, green, and blue components of an RGB image reside in a single m-by-n-by-3 array.
m and n are the numbers of rows and columns of pixels in the image, and the third dimension consists of three planes, containing red, green, and blue intensity values.
For each pixel in the image, the red, green, and blue elements combine to create the pixel’s actual color.
Working with Image Data
Reading in image data from files, and writing image data out to files
Converting images to other image types
Working with uint8 arrays in MATLAB and the Image Processing Toolbox
Writing Images
To write image data from MATLAB to a file, use the imwrite function. imwrite can write the same file formats that imread reads.
In addition, you can use the imfinfo function to return information about the image data in a file.
See the reference entries for imread, imwrite, and imfinfo for more information about these functions
Image Processing Using Matlab.ppt.ppt (Size: 669 KB / Downloads: 43)
What is the Image Processing Toolbox?
The Image Processing Toolbox is a collection of functions that extend the capability of the MATLAB ® numeric computing environment.
Many of the toolbox functions are MATLAB M-files, series of MATLAB statements that implement specialized image processing algorithms.
Geometric operations
Neighborhood and block operations
Linear filtering and filter design
Transforms
Image analysis and enhancement
Binary image operations
Region of interest operations
IP Toolbox
You can view the MATLAB code for these functions using the statement:
type function_name
You can extend the capabilities of the Image Processing Toolbox by writing your own M-files, or by using the toolbox in combination with with other toolboxes, such as the Signal Processing Toolbox and the Wavelet Toolbox.
Images in the Image Processing Toolbox
The basic data structure in MATLAB is the array, an ordered set of real or complex elements.
MATLAB stores most images as two-dimensional arrays (i.e., matrices), in which each element of the matrix corresponds to a single pixel in the displayed image.
For example, you can select a single pixel from an image matrix using normal matrix subscripting:
I(2,15)
Data Types Continued
In order to reduce memory requirements, MATLAB supports storing image data in arrays of class uint8. The data in these arrays is stored as 8-bit unsigned integers. Data stored in uint8 arrays requires one eighth as much memory as data in double arrays. (Noninteger values cannot be stored in uint8 arrays, for example, but they can be stored in double arrays.)
RGB Images
In MATLAB, the red, green, and blue components of an RGB image reside in a single m-by-n-by-3 array.
m and n are the numbers of rows and columns of pixels in the image, and the third dimension consists of three planes, containing red, green, and blue intensity values.
For each pixel in the image, the red, green, and blue elements combine to create the pixel’s actual color.
Working with Image Data
Reading in image data from files, and writing image data out to files
Converting images to other image types
Working with uint8 arrays in MATLAB and the Image Processing Toolbox
Writing Images
To write image data from MATLAB to a file, use the imwrite function. imwrite can write the same file formats that imread reads.
In addition, you can use the imfinfo function to return information about the image data in a file.
See the reference entries for imread, imwrite, and imfinfo for more information about these functions