enoca2.m

matlab程序

function X = enoca2(X,Level,Degree)
%ENOCA2  2D Essentially Non-Oscillatory cell-average decomposition.
%   Y = ENOCA(X,L,N) computes the L-stage Essentially Non-Oscillatory
%   (ENO) decomposition of image X using cell-average discretization
%   and Nth-degree interpolation.  The image dimensions must be divisible
%   by 2^L.
%
%   ENOCA2(X,-L,N) is the inverse transform, reversing L levels.
%
%   Example:
%   % Transform with 3 stages and 5th-degree interpolation
%   Y = enoca2(X,3,5);   % Decompose X
%   R = enoca2(Y,-3,5);  % Recover X from Y
%
%   See also ENOCA, ENOPV2.

% Pascal Getreuer 2005

if nargin < 2, error('Not enough input arguments.'); end
if rem(size(X),pow2(abs(Level))), error('Invalid input size.'); end

if Level > 0
   for k = 1:Level
      N = size(X)*pow2(1-k);
      X(1:N(1),1:N(2)) = enoca(enoca(X(1:N(1),1:N(2)),1,Degree,1),1,Degree,2);
   end
elseif Level < 0
   for k = Level:-1
      N = size(X)*pow2(k+1);
      X(1:N(1),1:N(2)) = enoca(enoca(X(1:N(1),1:N(2)),-1,Degree,2),-1,Degree,1);
   end
end