chapt04_Matlab图像处理基础.ppt

赵颖 zhaoying511@126.com 中南大学 Digital Image ProcessingMatlab图像处理基础 赵颖 zhaoying511@126.com 中南大学 安装图像处理包 确保安装Matlab时安装了图像处理包 安装图像处理包 The MATLAB Image Processing Toolbox The Image Processing Toolbox is a collection of MATLAB functions that extend the capability of the MATLAB environment for the solution of digital image processing problems. Including: -Spatial image transformations 空间变换 -Morphological operations 形态学处理 -Neighborhood and block operations 邻域处理 -Linear filtering and filter design 滤波 -Image analysis and enhancement 图像分析与增强 -Deblurring 锐化 -Region of interest operations 区域检测 -…. 数据类型 名称 描述 double 双精度浮点数，范围为-10exp(308)~ 10exp(308)，8字节 uint8 无符号8比特整数，1字节 uint16 无符号16比特整数，2字节 uint32 无符号32比特整数，4字节 int8 有符号8比特整数，1字节 int16 有符号16比特整数，2字节 int32 有符号32比特整数，4字节 single 单精度浮点数，范围为-10exp(38)~ 10exp(38) ，4字节 char 字符 logical 值为0或1 读取图像 imread Read image from graphics file A = imread(filename) A = imread(filename) reads a grayscale or color image from the file specified by the string filename. If the file is not in the current directory, or in a directory on the MATLAB path, specify the full pathname. The return value A is an array containing the image data. If the file contains a grayscale image, A is an M-by-N array. If the file contains a truecolor image, A is an M-by-N-by-3 array. For TIFF files containing color images that use the CMYK color space, A is an M-by-N-by-4 array. The class of A depends on the bits-per-sample of the image data, rounded to the next byte boundary. For example, imread returns 24-bit color data as an array of uint8 data because the sample size for each color component is 8 bits. 读取图像 举例 imread(‘d:\8位9像素灰度图片.BMP) 读取图像 显示某个像素的值 f = imread(d:\8位9像素灰度图片.BMP) g = imread(d:\64位全品红9像素CMYK图片.tif) f(1,2,:) g(1,2,:) 图像信息 Image size: size() 显示一幅图像的行数和列数 ex: f= imread( 8位9像素灰度图片.BMP); size(f) [M,N] = size(f) M=影像I的高 N=影像I的宽 图像信息 whos功用:display information about an image . ex: f= imread( 8位9像素灰度图片.BMP); whos f