perform_pyramid_transform.m

小波提升算法的实现

function y = perform_pyramid_transform(x,g,options)

% perform_pyramid_transform - fast pyramidal transform (1D or 2D).
%
% y = fwt_pyramid(x,g,options);
%
%   'g' is a 1D low pass filter (orthogonal or not).
%   if 'x' is vector, (forward transform), then
%       'x' is a 1D or 2D signal.
%       'y' is a cell array, y{i} is the detail at level i (1=biggest one)
%           and y{end} is the low scale decomposition.
%   if 'x' is a cell array (backward transform) then 
%       'x' is a cell array, and 'y' is a 1D or 2D signal
%
%   NB : for backward transform, the value of 
%
%   'options' is a struct that can contains
%       - 'bound': boundary extension (eiter 'sym' or 'per').
%       - 'J': number of scale for the forward transform. 
%
%   Copyright (c) 2004 Gabriel Peyr