梯度算子的Matlab实现

1、利用matlab编写的4种梯度算子程序。源代码如下：clear all;close all;P=input(input picture data:);subplot(231);imshow(P);title(原图像)；d=size(P);if(d(3)1)P=rgb2gray(P);endsubplot(232);imshow(P);title(灰度图像)；P=double(P);% Roberts Operatortou=input(input threshold tou=);bh=input(input a constant intensity nearer to white bh=);b

2、l=input(input a constant intensity nearer to black bl=);P1=P;for i=1:d(1)-1for j=1:d(2)-1RobNum=abs(P(i+1,j+1)-P(i,j)+abs(P(i,j+1)-P(i+1,j);if RobNum=touP1(i,j)=bh;elseP1(i,j)=bl;endendendP1=uint8(P1);subplot(233);imshow(P1);title(Roberts Operator);%Prewitt OperatorP2=P;for i=2:d(1)-1for j=2:d(2)-1P

3、reNum=1/6*(abs(P(i-1,j-1)+P(i-1,j)+P(i-1,j+1)-P(i+1,j-1)-P(i+1,j)-P(i+1,j+1)+abs(P(i-1,j-1)+P(i ,j-1)+P(i+1,j-1)-P(i-1,j+1)-P(i,j+1)-P(i+1,j+1);if PreNum=touP2(i,j)=bh;elseP2(i,j)=bl;endend endP2=uint8(P2);subplot(234);imshow(P2);title(Prewitt Operator);%Sobel OperatorP3=P;for i=2:d(1)-1for j=2:d(2)

4、-1SobNum=1/8*sqrt(P(i-1,j-1)+2*P(i-1,j)+P(i-1,j+1)-P(i+1,j-1)-2*P(i+1,j)-P(i+1,j+1)2+(P(i-1,j-1)+2*P(i,j-1)+P(i+1,j-1)-P(i-1,j+1)-2*P(i,j+1)-P(i+1,j+1)2);if SobNum=touP3(i,j)=bh;elseP3(i,j)=bl;endendendP3=uint8(P3);subplot(235);imshow(P3);title(Sobel Operator);%Laplacian OperatorP4=P;for i=2:d(1)-1for j=2:d(2)-1P4(i,j)=P(i+1,j)-2*P(i,j)+P(i-1,j)+P(i,j+1)-2*P(i,j)+P(i,j-1);en