checkancestors.m

EZW implementation which will use wavelet transforms and do the compression decompression using EZW

function   zerotree = checkancestors(j,R,zerotree)
% zerotree=1 means coefficient is descended from zerotree root
% initial set zerotree=0
global N;
i = floor((j+3)/4 ); 
while i>1,
    if R(N(i,1),N(i,2))==1;
        zerotree=1;
        break;
    end;
    i = floor((i+3)/4 );
end