Phụ lục
308
% the average gray level of the current block
m=mean(mean(blocco));
% the logical matrix correspoending to the current block
blocco_binario=(blocco>=m);
% the number of pixel (of the current block) whose gray level
% is greater than the average gray level of the current block
K=sum(sum(double(blocco_binario)));
% the average gray level of pixels whose level is GREATER than
% the block average gray level
mu=sum(sum(double(blocco_binario).*blocco))/K;
% the average gray level of pixels whose level is SMALLER than
% the block average gray level
if K==bx*by
ml=0;
else
ml=sum(sum(double(~blocco_binario).*blocco))/(bx*by-K);
end
% the COMPRESSED DATA which correspond to the input image
m_u(posbx,posby)=mu; %---> the m_u matrix
m_l(posbx,posby)=ml; %---> the m_l matrix
mat_log(ii:ii+bx-1,jj:jj+by-1)=blocco_binario;
%---> the logical matrix
% the compressed image
matrice(ii:ii+bx-1,jj:jj+by- ...
1)=(double(blocco_binario).*mu)+(double(~blocco_binario).*ml);
posby=posby+1;
end
posbx=posbx+1;
end
out_rgb(:,:,2)=matrice;
% ----------------------- BLUE component ------------------
dvalue=double_a(:,:,3);
dx=size(dvalue,1);
dy=size(dvalue,2);
% if input image size is not a multiple of block size image is resized
modx=mod(dx,bx);
mody=mod(dy,by);
dvalue=dvalue(1:dx-modx,1:dy-mody);
% the new input image dimensions (pixels)
dx=dx-modx;
