function P = block_divide(I,K) % P=block_divede(I) % [row,col]=size(I),row%K==0, and col%K==0 % divide matrix I into K*K block,and reshape to % a K^2*N matrix % example: % I=imread('lena.jpg'); % P=block_divide(I,4); % 計算塊的個數：R*C個 [row,col]=size(I); R=row/K; C=col/K; % 預分配空間 P=zeros(K*K,R*C); for i=1:R for j=1:C % 依次取K*K 圖像塊 I2=I((i-1)*K+1:i*K,(j-1)*K+1:j*K); % 將K*K塊變為列向量 i3=reshape(I2,K*K,1); % 將列向量放入矩陣 P(:,(i-1)*R+j)=i3; end end