dwt_aux.cpp

《Visual C++小波变换技术与工程实践》靳济芳编著的光盘程序。

    end = i;
    
    SegLength = end-start;
    odd = start%2;

    if(SegLength==1) { /* special case for single poInt */
#ifdef _DWT_INT_
      ret=DecomposeSegmentOddSymInt(InBuf+start, OutBuf+(start>>1), 
				    OutBuf+(Length>>1)+(start>>1), odd, 
				    SegLength, Filter);
#else
      ret=DecomposeSegmentOddSymDbl(InBuf+start, OutBuf+(start>>1), 
				    OutBuf+(Length>>1)+(start>>1), odd, 
				    SegLength, Filter);
#endif
	
      

      if(ret!=DWT_OK) return(ret);
      /* swap the subsampled mask for single poInt if highpass is IN */
      if(Direction == DWT_HORIZONTAL) {
	/* After horizontal decomposition, 
	   LP mask symbols: IN, OUT0;
	   HP mask symbols: IN, OUT0, OUT1 */
	if(OutMaskBuf[start>>1]==DWT_OUT0) { 
	  OutMaskBuf[start>>1] = DWT_IN;
	  OutMaskBuf[(start>>1)+(Length>>1)]=DWT_OUT1;
	}
      }
      else { /* vertical */
	/* After vertical decomposition, 
	   LLP mask symbols: IN, OUT0;
	   LHP mask symbols: IN, OUT2, OUT3;
	   HLP mask symbols: IN, OUT0, OUT1;
	   HHP mask symbols: IN, OUT0, OUT1, OUT2, OUT3 */
	if(OutMaskBuf[start>>1] == DWT_OUT0) {
	  OutMaskBuf[(start>>1)+(Length>>1)]= DWT_OUT2 ;
	  OutMaskBuf[start>>1] = DWT_IN;
	}
	else if(OutMaskBuf[start>>1] == DWT_OUT1) {
	  OutMaskBuf[(start>>1)+(Length>>1)]= DWT_OUT3 ;
	  OutMaskBuf[start>>1] = DWT_IN;
	}
      }
    }
    else {
#ifdef _DWT_INT_
      ret=DecomposeSegmentOddSymInt(InBuf+start, OutBuf+((start+1)>>1), 
				    OutBuf+(Length>>1)+(start>>1), odd, 
				    SegLength, Filter);

#else
      ret=DecomposeSegmentOddSymDbl(InBuf+start, OutBuf+((start+1)>>1), 
				    OutBuf+(Length>>1)+(start>>1), odd, 
				    SegLength, Filter);
#endif
      if(ret!=DWT_OK) return(ret);
    }
  }
  return(DWT_OK);
}

/* 
   Function:  DecomposeSegmentOddSymInt() or  DecomposeSegmentOddSymDbl()
   Description: SA-Decompose a 1D segment based on its InitPos and Length using
                Odd-Symmetric Filters
   Input:

   In -- Input data segment;
   PosFlag -- Start position of this segment (ODD or EVEN);
   Length -- Length of this Segment;
   Filter -- Filter used;
   
   Output:

   OutL -- Low pass data;
   OutH -- High pass data;

   Return: Return DWT_OK if Successful
*/
#ifdef _DWT_INT_
Int VTCDWT:: DecomposeSegmentOddSymInt(DWTDATA *In, DWTDATA *OutL, DWTDATA *OutH, 
				     Int PosFlag, Int Length, FILTER *Filter)
#else
Int VTCDWT:: DecomposeSegmentOddSymDbl(DWTDATA *In, DWTDATA *OutL, DWTDATA *OutH, 
				     Int PosFlag, Int Length, FILTER *Filter)
#endif

{
  /* filter coefficients */
#ifdef _DWT_INT_
  Short *LPCoeff = (Short *)Filter->LPCoeff, *HPCoeff = (Short *)Filter->HPCoeff; 
  Short *fi;
#else
  double *LPCoeff = (double *)Filter->LPCoeff, *HPCoeff = (double *)Filter->HPCoeff; 
  double *fi;
#endif
  Int ltaps = Filter->LPLength, htaps = Filter->HPLength; /* filter lengths*/
  Int loffset = ltaps/2, hoffset = htaps/2;  /* Filter offset */
  Int border = (ltaps>htaps)?ltaps:htaps; /*the larger of ltaps and htaps */
  Int m, n;
  DWTDATA *f,*pixel, *pixel1, val, *buf, *a;
  Int r = Length-1;
  /* prIntf("Length=%d\n", Length); */
  if(Length == 1) {
	*OutL = 0; // hjlee 0928
	for (m=0; m<ltaps;m++)
		*OutL += *In * (*(LPCoeff+m)); 
    /* *OutL = *In * Filter->Scale; */
    return (DWT_OK);
  }

  /* allocate proper buffer */
  buf = (DWTDATA *) malloc((Length+2*border)*sizeof(DWTDATA));
  if(buf==NULL)  return(DWT_MEMORY_FAILED);
  /* now symmetric extend this segment */
  a = buf+border;
  for(m=0;m< Length; m++) {
    a[m] = In[m];
    /* prIntf("%f ", a[m]); */
  }
  /* prIntf("\n"); */
  /* symmetric extension */
  for (m=1 ; m<=border; m++)
  {
    a[-m] =  a[m];  /* to allow Shorter seg */
    a[r+m] = a[r-m]; 
  }

  f = buf + border + Length;
  /* always subsample even positions in a line for LP coefficents */
  if (PosFlag==DWT_ODD) a = buf + border + 1;
  else a = buf + border;

  for (; a<f; a +=2)
  {
    /* filter the pixel with lowpass filter */
    for( fi=LPCoeff, pixel=a-loffset, pixel1=pixel+ltaps-1,val=0, n=0; 
	 n<(ltaps>>1); 
	 n++, fi++, pixel++, pixel1--)
      val += (*fi * (*pixel + *pixel1)); /* symmetric */
    val += (*fi * *pixel);
    *OutL++ = val;
  }
  /* always  subsample odd positions in a line for HP coefficients */
  if (PosFlag==DWT_ODD) a = buf + border;
  else a = buf + border+1;

  for (; a<f; a +=2)
    {
      /* filter the pixel with highpass filter */
      for(fi=HPCoeff, pixel=a-hoffset, pixel1 = pixel+htaps-1, val=0, n=0; 
	  n<(htaps>>1); 
	  n++, fi++, pixel++, pixel1--)
	val += (*fi *  (*pixel + *pixel1));  /* symmetric */
      val += (*fi * *pixel);
      *OutH++ = val;
    }
  free(buf);
  return(DWT_OK);
}

/* Function: SADWT1dEvenSymInt() or SADWT1dEvenSymDbl()
   Description: 1D  SA-DWT using Even Symmetric Filter
   Input:

   InBuf -- Input 1d data buffer
   InMaskBuf -- Input 1d mask buffer
   Length -- length of the input data
   Filter -- filter used
   Direction -- vertical or horizontal decomposition (used for inversible 
   mask decomposition)

   Output:
   
   OutBuf -- Transformed 1d Data
   OutMask -- Mask for the Transformed 1d Data

   Return: return DWT_OK if successful

*/
#ifdef _DWT_INT_
Int VTCDWT:: SADWT1dEvenSymInt(DWTDATA *InBuf, UChar *InMaskBuf, DWTDATA *OutBuf, 
			     UChar *OutMaskBuf, Int Length, FILTER *Filter, 
			     Int Direction)
#else
Int VTCDWT:: SADWT1dEvenSymDbl(DWTDATA *InBuf, UChar *InMaskBuf, DWTDATA *OutBuf, 
			     UChar *OutMaskBuf, Int Length, FILTER *Filter, 
			     Int Direction)
#endif

{
  Int i;
  Int SegLength = 0;
  Int odd;
  Int start, end;
  UChar *a, *b, *c;
  Int ret;
  /* double check filter class and type */
  if(Filter->DWT_Class != DWT_EVEN_SYMMETRIC) return(DWT_INTERNAL_ERROR);
#ifdef _DWT_INT_
  if(Filter->DWT_Type != DWT_INT_TYPE)  return(DWT_INTERNAL_ERROR);
#else
  if(Filter->DWT_Type != DWT_DBL_TYPE)  return(DWT_INTERNAL_ERROR);
#endif
  /* double check if Length is even */
  if(Length & 1) return(DWT_INTERNAL_ERROR);
  /* initial mask output */
  for(a=InMaskBuf, b = OutMaskBuf, c= OutMaskBuf+(Length>>1); a<InMaskBuf+Length;) {
    *b++ = *a++;
    *c++ = *a++;
  }
  /* initial OutBuf to zeros */
  memset(OutBuf, (UChar)0, sizeof(DWTDATA)*Length);
  
  i = 0;
  a = InMaskBuf;
  while(i<Length) {
    /* search for a segment */
    while(i<Length && (a[i])!=DWT_IN) i++;
    start = i;
    if(i >= Length) break;
    while(i<Length && (a[i])==DWT_IN) i++;
    end = i;
    SegLength = end-start;
    odd = start%2;
    if(SegLength==1) { /* special case for single poInt */
#ifdef _DWT_INT_
      ret=DecomposeSegmentEvenSymInt(InBuf+start, OutBuf+(start>>1), 
				     OutBuf+(Length>>1)+(start>>1), odd, 
				     SegLength, Filter);
#else
      ret=DecomposeSegmentEvenSymDbl(InBuf+start, OutBuf+(start>>1), 
				     OutBuf+(Length>>1)+(start>>1), odd, 
				     SegLength, Filter);
#endif

      if(ret!=DWT_OK) return(ret);
 
    }
    else {
#ifdef _DWT_INT_
      ret=DecomposeSegmentEvenSymInt(InBuf+start, OutBuf+(start>>1), 
				     OutBuf+(Length>>1)+((start+1)>>1), odd, 
				     SegLength, Filter);
#else
      ret=DecomposeSegmentEvenSymDbl(InBuf+start, OutBuf+(start>>1), 
				     OutBuf+(Length>>1)+((start+1)>>1), odd, 
				     SegLength, Filter);
#endif
	
      if(ret!=DWT_OK) return(ret);
    }
    /* swap the subsampled mask for the start of segment if it is odd*/
    if(odd) {
      if(Direction == DWT_HORIZONTAL) {
	/* After horizontal decomposition, 
	   LP mask symbols: IN, OUT0;
	   HP mask symbols: IN, OUT0, OUT1 */
	if(OutMaskBuf[start>>1]==DWT_OUT0) { 
	  OutMaskBuf[start>>1] = DWT_IN;
	  OutMaskBuf[(start>>1)+(Length>>1)]=DWT_OUT1;
	}
      }
      else { /* vertical */
	/* After vertical decomposition, 
	   LLP mask symbols: IN, OUT0;
	   LHP mask symbols: IN, OUT2, OUT3;
	   HLP mask symbols: IN, OUT0, OUT1;
	   HHP mask symbols: IN, OUT0, OUT1, OUT2, OUT3 */
	if(OutMaskBuf[start>>1] == DWT_OUT0) {
	  OutMaskBuf[(start>>1)+(Length>>1)]= DWT_OUT2 ;
	  OutMaskBuf[start>>1] = DWT_IN;
	}
	else if(OutMaskBuf[start>>1] == DWT_OUT1) {
	  OutMaskBuf[(start>>1)+(Length>>1)]= DWT_OUT3 ;
	  OutMaskBuf[start>>1] = DWT_IN;
	}
      }
    }
  }
  return(DWT_OK);
}

/* 
   Function:  DecomposeSegmentEvenSymInt() or DecomposeSegmentEvenSymDbl()
   Description: SA-Decompose a 1D segment based on its InitPos and Length using
                Even-Symmetric Filters
   Input:

   In -- Input data segment;
   PosFlag -- Start position of this segment (ODD or EVEN);
   Length -- Length of this Segment;
   Filter -- Filter used;
   
   Output:

   OutL -- Low pass data;
   OutH -- High pass data;

   Return: Return DWT_OK if Successful
*/
#ifdef _DWT_INT_
Int VTCDWT:: DecomposeSegmentEvenSymInt(DWTDATA *In, DWTDATA *OutL, DWTDATA *OutH, 
				      Int PosFlag, Int Length, FILTER *Filter)
#else
Int VTCDWT:: DecomposeSegmentEvenSymDbl(DWTDATA *In, DWTDATA *OutL, DWTDATA *OutH, 
				      Int PosFlag, Int Length, FILTER *Filter)
#endif

{
  /* filter coefficients */
#ifdef _DWT_INT_
  Short *LPCoeff = (Short *)Filter->LPCoeff, *HPCoeff = (Short *)Filter->HPCoeff; 
  Short *fi;
#else
  double *LPCoeff = (double *)Filter->LPCoeff, *HPCoeff = (double *)Filter->HPCoeff; 
  double *fi; 
#endif
  Int ltaps = Filter->LPLength, htaps = Filter->HPLength; /* filter lengths*/
  Int loffset = ltaps/2-1, hoffset = htaps/2-1;  /* Filter offset */
  Int border = (ltaps>htaps)?ltaps:htaps; /*the larger of ltaps and htaps */
  Int m, n;
  DWTDATA *f,*pixel, *pixel1, val, *buf, *a;
  Int r = Length-1;

  if(Length == 1) {
	*OutL = 0;  // hjlee 0928
	for (m=0;m<ltaps; m++)
		*OutL += *In * (*(LPCoeff+m));  // hjlee 0928
    /* *OutL = *In * Filter->Scale; */
    return (DWT_OK);
  }
  /* allocate proper buffer */
  buf = (DWTDATA *) malloc((Length+2*border)*sizeof(DWTDATA));
  if(buf==NULL)  return(DWT_MEMORY_FAILED);
  /* now symmetric extend this segment */
  a = buf+border;
  for(m=0;m< Length; m++) {
    a[m] = In[m];
  }
  /* symmetric extension */
  for (m=1 ; m<=border; m++)
  {
    a[-m] =  a[m-1];  /* to allow Shorter seg */
    a[r+m] = a[r-m+1]; 
  }

  f = buf + border + Length;
  /* always subsample even positions in a line for LP coefficents */
  if (PosFlag==DWT_ODD) a = buf + border - 1;
  else a = buf + border;

  for (; a<f; a +=2)
  {
    /* filter the pixel with lowpass filter */
    for( fi=LPCoeff, pixel=a-loffset, pixel1=pixel+ltaps-1, val=0, n=0; 
	 n<(ltaps>>1); 
	 n++, fi++, pixel++, pixel1--)
      val += (*fi * (*pixel + *pixel1));  /* symmetric */

    *OutL++ = val;
  }
  /* always  subsample even positions in a line for HP coefficients */
  if (PosFlag==DWT_ODD) a = buf + border +1;
  else a = buf + border;

  for (; a<f; a +=2)
    {
      /* filter the pixel with highpass filter */
      for(fi=HPCoeff, pixel=a-hoffset, pixel1 = pixel+htaps-1, val=0, n=0; 
	  n<(htaps>>1); 
	  n++, fi++, pixel++, pixel1--)
	val += (*fi *  (*pixel - *pixel1)); /* antisymmetric */
      *OutH++ = val;
  }
  free(buf);
  return(DWT_OK);
}

#ifdef _DWT_INT_
#undef _DWT_INT_
#define _DWT_DBL_
#include "dwt_aux.cpp"
#endif