function y=sharper(x,j,t)

%SHARPER    Scales wavelet coefficients 

%--------------------------------------------------------
%      Author: J. M. Aroca
%
%      e-mail: jomaroca@mat.upc.es
%--------------------------------------------------------


sz=size(x);
a=sz(1);
if a<2^j or sz(2)~=a
   disp('invalid arguments')
	return
end

[h,g,hr,gr]=daub(4);
xw=wt2d(x,h,g,j);

z=ones(a/2^j,a/2^j);
for k=1:j
   z=[z,t*z;t*z,t*z];
end

xws=xw.*z;
y=iwt2d(xws,hr,gr,j);
