perform_alpert_transform_2d_sliced.m

该程序为用MATLAB编写的一个小波变换工具箱

function [w,info] = perform_alpert_transform_2d_sliced(v,pos,k,s, dir)

% perform_alpert_transform_2d_sliced - perform a forward 2D Alpert transform. You can specify a number of slice in the Y direction.
%
%   [w,info] = perform_alpert_transform_2d_sliced(v,pos,k,s, dir);
%
%   This will perform a 1.5D alpert transform on each slice  Si = { (x,y) \ (i-1)/s <= y < i/s }
%
%   'v' is the data to transform.
%   'pos' is the sampling location, a 2D vector, pos(:,i) is the ith point.
%   'k' is the number of vanishing moments (1=>Haar, 2=>linear basis ...).
%       * 'k' can be an integer, and then the algorithm will use the same
%         order 'k' for X and Y directions.
%       * 'k' can be a couple of integer k=[kx,ky] and 'kx' will be the
%         order on the X direction, and 'ky' the order on the Y direction.
%   's' is the number of slices (slices paralel to X).
%   'dir' is either 1 (fwd transform) or -1 (bwd).
%
%   'w' is the transformed data.
%   'info' is a struct containing the localisation information for each
%       basis Alpert vector.
%       'info.l' is the scale of the vector (0=coarse scale).
%       'info.n' is the space location of the vector.
%       'info.k' is the number of multiwavelet (in [1,...,k(1)*k(2)]).
%       'info.s' is the number of the slice.
%
%   Copyright (c) 2004 Gabriel Peyr