数字图像处理 空间域锐化 MATLAB实验

一、原理_空间域锐化

设图像为 f(x,y) ，

Roberts算子的定义式为：

其对应的模板为：

Prewitt算子的定义式为：

其中，

其对应的模板为：

Sobel算子的定义式为：

其中，

其对应的模板为：

Laplacian算子的定义式为：

其对应的模板为：

二、步骤

(1)读入原图像lena.bmp并显示;

(2)分别采用Roberts算子、Prewitt算子、Sobel算子计算图像的梯度；

(3)采用Laplacian增强算子对图像进行增强，并显示增强结果；

(4)比较各种锐化算子对图像边缘的增强效果。

三、实验图像

四、框图

五、代码

%------------------------------------------------------------------------% File name: third_2% Last modified Date: 6月10日20点24分% Author: Jasmine% Descriptions: 空间域锐化%------------------------------------------------------------------------%清空工作区clc,clear,close all;%读入原图像lena = imread('D:\_1Course\Digital_image_processing\photo\lena.bmp');lena=rgb2gray(lena);%显示原图像subplot(3,2,1),imshow(lena);title('原图');[ROW,COL] = size(lena);lena = double(lena);new_img = zeros(ROW,COL); %新建画布%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%定义robert算子roberts_x = [-1,0;0,1];roberts_y = [0,-1;1,0];for i = 1:ROW - 1for j = 1:COL - 1funBox = lena(i:i+1,j:j+1);G_x = roberts_x .* funBox;G_x = abs(sum(G_x(:)));G_y = roberts_y .* funBox;G_y = abs(sum(G_y(:)));roberts_xy = G_x * 0.5 + G_y * 0.5;new_img(i,j) = roberts_xy;endendsubplot(3,2,3),imshow(new_img/255),title("robert算子的图像");%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 定义laplace算子laplace = [0,1,0;1,-4,1;0,1,0];for i = 1:ROW - 2for j = 1:COL - 2funBox = lena(i:i+2,j:j+2);G = laplace .* funBox;G = abs(sum(G(:)));new_img(i+1,j+1) = G;endendsubplot(3,2,4),imshow(new_img/255),title("laplace算子的图像");%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%定义sobel算子sobel_x = [-1,0,1;-2,0,2;-1,0,1];sobel_y = [-1,-2,-1;0,0,0;1,2,1];for i = 1:ROW - 2for j = 1:COL - 2funBox = lena(i:i+2,j:j+2);G_x = sobel_x .* funBox;G_x = abs(sum(G_x(:)));G_y = sobel_y .* funBox;G_y = abs(sum(G_y(:)));sobelxy = G_x * 0.5 + G_y * 0.5;new_img(i+1,j+1) = sobelxy;endendsubplot(3,2,5),imshow(new_img/255),title("sobel算子的图像");%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%定义Prewitt算子sobel_x = [-1,0,1;-1,0,1;-1,0,1];sobel_y = [-1,-1,-1;0,0,0;1,1,1];for i = 1:ROW - 2for j = 1:COL - 2funBox = lena(i:i+2,j:j+2);G_x = sobel_x .* funBox;G_x = abs(sum(G_x(:)));G_y = sobel_y .* funBox;G_y = abs(sum(G_y(:)));sobelxy = G_x * 0.5 + G_y * 0.5;new_img(i+1,j+1) = sobelxy;endendsubplot(3,2,6),imshow(new_img/255),title("Prewitt算子的图像");

六、运行结果