matlab_基于基元共生矩阵的纹理特征提取。通过5个基本的方格来检测图像并生成图像的基元共生矩阵，并从矩阵中提取其纹理特征信息

%A=[2,4,0,3,4;2,2,1,0,0;0,2,1,1,3;3,3,2,4,4;3,3,2,1,4]; A=imread('sample.jpg'); s=size(A); M=s(1); N=s(2); B=zeros(M,N,5); %% 将彩色图像转换成灰度级 if length(s)==3 A=rgb2gray(A); end %% 运用五种基元对图像进行检测最后合成一个texton image T for i=1:M-1 for j=1:N-1 if A(i,j) == A(i,j+1)&&A(i,j) == A(i+1,j) B(i,j,1)=A(i,j); B(i,j+1,1)=A(i,j+1); B(i+1,j,1)=A(i+1,j); end if A(i,j) == A(i,j+1)&&A(i,j) == A(i+1,j+1) B(i,j,2)=A(i,j); B(i,j+1,2)=A(i,j+1); B(i+1,j+1,2)=A(i+1,j+1); end if A(i,j) == A(i+1,j)&&A(i,j) == A(i+1,j+1) B(i,j,3)=A(i,j); B(i+1,j,3)=A(i+1,j); B(i+1,j+1,3)=A(i+1,j+1); end if A(i,j+1) == A(i+1,j)&&A(i,j+1) == A(i+1,j+1) B(i,j+1,4)=A(i,j+1); B(i+1,j,4)=A(i+1,j); B(i+1,j+1,4)=A(i+1,j+1); end if A(i,j+1) == A(i+1,j)&&A(i,j+1) == A(i+1,j+1)&&A(i,j+1) == A(i,j) B(i,j,5)=A(i,j); B(i,j+1,5)=A(i,j+1); B(i+1,j,5)=A(i+1,j); B(i+1,j+1,5)=A(i+1,j+1); end end end %texton image T=zeros(M,N); for i=1:M for j=1:N if B(i,j,1)~=0 T(i,j)=B(i,j,1); elseif B(i,j,2)~=0 T(i,j)=B(i,j,2); elseif B(i,j,3)~=0 T(i,j)=B(i,j,3); elseif B(i,j,4)~=0 T(i,j)=B(i,j,4); elseif B(i,j,5)~=0 T(i,j)=B(i,j,5); end end end %% 对原始图像压缩，将灰度量化到16 for i = 1:M for j = 1:N for n = 1:256/16 if (n-1)*16<=T(i,j)&&T(i,j)<=(n-1)*16+15 T(i,j) = n-1; end end end end %% four directional texton co-occurrence matrixes. TT=zeros(16,16,4); %angle 0 for i=1:16 for j=1:16 for x=1:M for y=1:N if y<N && T(x,y)==i-1 && T(x,y+1)==j-1 TT(i,j,1)=TT(i,j,1)+1; end if x<M && y<N && T(x,y)==i-1 && T(x+1,y+1)==j-1 TT(i,j,2)=TT(i,j,2)+1; end if x<M && T(x,y)==i-1 && T(x+1,y)==j-1 TT(i,j,3)=TT(i,j,3)+1; end if x<M && y>1&&T(x,y)==i-1 && T(x+1,y-1)==j-1 TT(i,j,4)=TT(i,j,4)+1; end end end end end %共生矩阵归一化 for n = 1:4 TT(:,:,n) = TT(:,:,n)/sum(sum(TT(:,:,n))); end %对共生矩阵计算energy,contrast,entropy,homogeneity4个纹理参数 H = zeros(1,4);C = H;E1 = H;E2=H; for n = 1:4 E1(n) = sum(sum(TT(:,:,n).^2)); for i = 1:16 for j=1:16 if TT(i,j,n)~=0 E2(n)=-TT(i,j,n)*log(TT(i,j,n))+E2(n); end C(n)=(i-j)^2*TT(i,j,n)+C(n); H(n)=TT(i,j,n)/(1+(i-j)^2); end end end