matlab实现数字图像处理

function yasuobi=hide_2(A1,info) %每隔两个DCT系数置换一个 A=double(A1); %分块 [p q]=size(A); a=ceil(p/8); b=ceil(q/8); block=zeros(8,8,a*b); for m=1:a for n=1:b %每一小块 for s=1:8 for t=1:8 block(s,t,m*b-b+n)=A(8*m-8+s,8*n-8+t); end end end end DCT=zeros(8,8,a*b); %DCT变换 for m=1:a*b DCT(:,:,m)=dct2(block(:,:,m)); end %量化 load JpegCoeff; NUM=zeros(8,8,a*b); for m=1:a*b NUM(:,:,m)=round(DCT(:,:,m)./QTAB); end dec=info_dec(info); dec_double=double(dec)-48; length_dec=length(dec); num_block=ceil(length_dec*3/64); count=1;x=1; for m=1:num_block+1 for n=1:8 for t=1:8 if(count<=3*length_dec+1) if(mod(count,3)==1) sign=1; if(NUM(n,t,m)<0) sign=-1; end if(count~=3*length_dec+1) NUM(n,t,m)=sign*(floor(abs(NUM(n,t,m))/10)*10+dec_double(x)); x=x+1; end if(count==3*length_dec+1) NUM(n,t,m)=sign*(floor(abs(NUM(n,t,m))/10)*10+5); end end end count=count+1; end end end %zig_zag Zig=zeros(64,a*b); for m=1:a*b Zig(:,m)=zig_zag_2(NUM(:,:,m)); end %对DC 系数先做差分编码 for m=1:a*b if(m==1) CD(m)=Zig(1,m); else CD(m)=Zig(1,m-1)-Zig(1,m); end end %DC编码 DC_code=''; for m=1:length(CD) DC_code=strcat(DC_code,dc_code(CD(m))); end %AC编码 AC_code=''; for m=1:a*b AC_code=strcat(AC_code,ac_code(Zig(2:64,m))); end yasuobi=yasuo(AC_code,DC_code,A1); save hide_2.mat p q DC_code AC_code; %end