基于小波分析的纹理分割

/* * SQRDIST : calculate a nt*nx matrix containing weighted squared error between * every vector in x and every vector in t * D = sqrDist(x,t,w) * x - d*nx matrix containing the x vectors * t - d*nt matrix containing the t vectors * w - if specified, a length d weight vector * D - the nt*nx result * * Copyright (c) 1995-2001 Frank Dellaert * All rights Reserved */ /****************************************************************************** * weightedSqrDist_c and sqrDist_c do not include mex.h *****************************************************************************/ void weightedSqrDist_c(const double *x, const double *t, const double *w, int nt, int nx, int d, double *D) { int i,j,k; const double *xj=x; for (j=0;j<nx;j++,xj+=d) { const double *ti=t; for (i=0;i<nt;i++,D++,ti+=d) { *D=0; for (k=0;k<d;k++) { double dk=w[k]*(xj[k]-ti[k]); *D += dk*dk; } } } } void sqrDist_c(const double *x, const double *t, int nt, int nx, int d, double *D) { int i,j,k; const double *xj=x; for (j=0;j<nx;j++,xj+=d) { const double *ti=t; for (i=0;i<nt;i++,D++,ti+=d) { *D=0; for (k=0;k<d;k++) { double dk=xj[k]-ti[k]; *D += dk*dk; } } } } /****************************************************************************** * mex part *****************************************************************************/ #include "mex.h" mxArray *sqrDist(const mxArray *x, const mxArray *t, const mxArray *w) { mxArray *D; int dx=mxGetM(x),nx=mxGetN(x); int dt=mxGetM(t),nt=mxGetN(t); int d = (w==NULL) ? dt : mxGetN(w)*mxGetM(w); if (dt!=dx) mexErrMsgTxt("x and t must have same dimension"); if ( d!=dx) mexErrMsgTxt("w has wrong number of elements"); if (!mxIsDouble(x) || !mxIsDouble(t)) mexErrMsgTxt("sqrDist only takes double vectors"); /* create output matrix and call pure C */ D = mxCreateDoubleMatrix(nt,nx,mxREAL); if (w==NULL) sqrDist_c(mxGetPr(x), mxGetPr(t), nt, nx, dx, mxGetPr(D)); else weightedSqrDist_c(mxGetPr(x), mxGetPr(t), mxGetPr(w), nt, nx, dx, mxGetPr(D)); return D; } void mexFunction(int nargout, mxArray *out[], int nargin, const mxArray *in[]) { if ((nargin!=2 && nargin!=3) || nargout>1) mexErrMsgTxt("usage: D = sqrDist(x,t,w)"); out[0] = sqrDist(in[0], in[1], nargin == 3 ? in[2] : NULL); }