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haar.h

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```00001
00002 #ifndef _HAAR_H_
00003 #define _HAAR_H_
00004
00005 #include <math.h>
00006
00007 #include "liftbase.h"
00008
00041
00078 template <class T>
00079 class haar : public liftbase<T, double> {
00080
00081 protected:
00085   void predict( T& vec, int N, transDirection direction )
00086   {
00087     int half = N >> 1;
00088
00089     for (int i = 0; i < half; i++) {
00090       double predictVal = vec[i];
00091       int j = i + half;
00092
00093       if (direction == forward) {
00094         vec[j] = vec[j] - predictVal;
00095       }
00096       else if (direction == inverse) {
00097         vec[j] = vec[j] + predictVal;
00098       }
00099       else {
00100         printf("haar::predict: bad direction value\n");
00101       }
00102     }
00103   }
00104
00105
00134   void update( T& vec, int N, transDirection direction )
00135   {
00136     int half = N >> 1;
00137
00138     for (int i = 0; i < half; i++) {
00139       int j = i + half;
00140       double updateVal = vec[j] / 2.0;
00141
00142       if (direction == forward) {
00143         vec[i] = vec[i] + updateVal;
00144       }
00145       else if (direction == inverse) {
00146         vec[i] = vec[i] - updateVal;
00147       }
00148       else {
00149         printf("update: bad direction value\n");
00150       }
00151     }
00152   }
00153
00182   void normalize( T& vec, int N, transDirection direction )
00183   {
00184     const double sqrt2 = sqrt( 2.0 );
00185     int half = N >> 1;
00186
00187     for (int i = 0; i < half; i++) {
00188       int j = i + half;
00189
00190       if (direction == forward) {
00191         vec[i] = sqrt2 * vec[i];
00192         vec[j] = vec[j]/sqrt2;
00193       }
00194       else if (direction == inverse) {
00195         vec[i] = vec[i]/sqrt2;
00196         vec[j] = sqrt2 * vec[j];
00197       }
00198       else {
00199         printf("normalize: bad direction value\n");
00200       }
00201     } // for
00202   } // normalize
00203
00207   void inverseStep( T& vec, const int n )
00208   {
00209     normalize( vec, n, inverse );
00210     update( vec, n, inverse );
00211     predict( vec, n, inverse );
00212     merge( vec, n );
00213   }  // inverseStep
00214
00218   void forwardStep( T& vec, const int n )
00219   {
00220     split( vec, n );
00221     predict( vec, n, forward );
00222     update( vec, n, forward );
00223     normalize( vec, n, forward );
00224   } // forwardStep
00225
00226
00227 }; // haar
00228
00229 #endif
```

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