spiht.cpp

根据paper思想

			}
			else if ((x%2 == 0)&&(y%2 != 0)) 
			{
				min_x = x;
				max_x = min_x + 2;
				min_y = y - 1;
				max_y = min_y + 2;
				subband0 = 2;
			}
			else
			{
				min_x = x -1;
				max_x = min_x + 2;
				min_y = y -1;
				max_y = min_y + 2;
				subband0 = 3;
			}
		}
		else
		{
			if (band%3 == 1) 
			{
				min_x = (x-subbandxsize[band]) << 1;
				max_x = min_x + 2;
				min_y = y << 1;		
				max_y = min_y + 2;
			}
			else if (band%3 == 2) 
			{
				min_x = x << 1;
				max_x = min_x + 2;
				min_y = (y-subbandysize[band]) <<1;		
				max_y = min_y + 2;
			}
			else
			{
				min_x = (x-subbandxsize[band]) << 1;
				max_x = min_x + 2;
				min_y = (y-subbandysize[band]) << 1;		
				max_y = min_y + 2;
			}
			
			subband0 = 3;
		}
		
		
		min_x <<= 1;
		max_x <<= 1;
		min_y <<= 1;
		max_y <<= 1;

		return(!ZeroTree(m,threshold,band+subband0,min_x,max_x,min_y,max_y));	
	}
	
	if(stop==1)
		return 1;
	else
		return 0;
	
}

void CSPIHT::SortingPass1(CMatrix2D<ElementType> *m, int threshold)
{
	int temp, s, i, j;
	int band;
	int maxy,maxx;
	char found;
	CLinkList::ListType d, d1;
	if(stop==1)
		return;
    pNewlyAppended = LSP->end;

	/* Deal with elements in the LIP */
	LIP->Reset();
	while(LIP->current!=NULL)
	{
		d = LIP->GetCurrentElement(&found);
		if(found==0)
		{
			cout << "Warning: Can't retrieve current list element..\n";
			return;
		}
		temp = m->m[d.y][d.x];
		if(abs(temp)<threshold) 
		{
			PutBit(0);
			if(stop==1)
				return;
			LIP->current = LIP->current->next;
		}
		else
		{
			PutBit(1);
			if(temp>0)
				PutBit(1);
			else
				PutBit(0);
			if(stop==1)
				return;
			LIP->RemoveCurrentElement();
			LSP->Append(d);
		}
	}
	LIP->Reset();
	
	/* Deal with elements in the LIS */
	LIS->Reset();
	while(LIS->current!=NULL)
	{
		d = LIS->GetCurrentElement(&found);		
		if(found==0)
		{
			cout<<"Warning: Can't retrieve current list element.\n";
			return;
		}
		band=FindSubband(d.x,d.y);
		s = TestSubset(m,d.x,d.y,threshold,d.type,band);
		if(d.type==TYPE_A)
		{
			PutBit((char)s);
			if(stop==1)
				return;
			if(s==1)
			{
				
				if(band!=0)
				{
					if (band%3 == 1)
					{
						maxx = (d.x-subbandxsize[band]) << 1;
						maxy = d.y << 1;
					}
					else if (band%3 == 2) 
					{
						maxx=d.x << 1;
						maxy=(d.y-subbandysize[band]) << 1;
					}
					else
					{
						maxx=(d.x-subbandxsize[band]) << 1;
						maxy=(d.y-subbandysize[band]) << 1;
					}
					
					for(j = maxy; j < maxy+2; j++) 
					{
						for(i = maxx; i < maxx+2; i++)
						{
							if(band%3 == 1)
							{
								d1.x = subbandxsize[band+3]+i;
								d1.y = j;
								temp = m->m[d1.y][d1.x];
							}
							else if(band%3 == 2)
							{
								d1.x = i;
								d1.y = subbandysize[band+3]+j;
								temp = m->m[d1.y][d1.x];
							}
							else
							{
								d1.x = subbandxsize[band+3]+i;
								d1.y = subbandysize[band+3]+j;
								temp = m->m[d1.y][d1.x];
							}
							
							if(abs(temp)>=threshold)
							{
								PutBit(1);
								if(stop==1)
									return;
								LSP->Append(d1);
								if(temp>0)
									PutBit(1);
								else
									PutBit(0);
								if(stop==1)
									return;
								
							}
							else 
							{
								PutBit(0);
								if(stop==1)
									return;
								LIP->Append(d1);
							}
						}
					}
				}
				else
				{
					if((d.x%2 != 0)&&(d.y%2 == 0))
					{
						maxx = d.x -1;					
						maxy = d.y;
						for(j = maxy; j < maxy + 2; j++)
						{
							for(i = maxx; i < maxx + 2; i++)
							{
								d1.x = subbandxsize[0]+i;
								d1.y = j;
								temp = m->m[d1.y][d1.x];
								if(abs(temp)>=threshold)
								{
									PutBit(1);
									if(stop==1)
										return;
									LSP->Append(d1);
									if(temp>0)
										PutBit(1);
									else
										PutBit(0);
									if(stop==1)
										return;
									
								}
								else 
								{
									PutBit(0);
									if(stop==1)
										return;
									LIP->Append(d1);
								}
							}							
						}						
					}

					if((d.x%2 == 0)&&(d.y%2 != 0))
					{
						maxx = d.x;					
						maxy = d.y -1;
						for(j = maxy; j < maxy + 2; j++)
						{
							for(i = maxx; i < maxx + 2; i++)
							{
								d1.x = i;
								d1.y = subbandysize[0]+j;
								temp = m->m[d1.y][d1.x];
								if(abs(temp)>=threshold)
								{
									PutBit(1);
									if(stop==1)
										return;
									LSP->Append(d1);
									if(temp>0)
										PutBit(1);
									else
										PutBit(0);
									if(stop==1)
										return;
									
								}
								else 
								{
									PutBit(0);
									if(stop==1)
										return;
									LIP->Append(d1);
								}
							}							
						}						
					}
					
					if((d.x%2 != 0)&&(d.y%2 != 0))
					{
						maxx = d.x - 1;					
						maxy = d.y - 1;
						for(j = maxy; j < maxy + 2; j++)
						{
							for(i = maxx; i < maxx + 2; i++)
							{
								d1.x = subbandxsize[0]+i;
								d1.y = subbandysize[0]+j;
								temp = m->m[d1.y][d1.x];
								if(abs(temp)>=threshold)
								{
									PutBit(1);
									if(stop==1)
										return;
									LSP->Append(d1);
									if(temp>0)
										PutBit(1);
									else
										PutBit(0);
									if(stop==1)
										return;
									
								}
								else 
								{
									PutBit(0);
									if(stop==1)
										return;
									LIP->Append(d1);
								}
							}							
						}						
					}
				}
					
				//如果（d.y,d.x）有孙子节点
				if(band < subbands - 6)
				{
					d1 = d;
					d1.type = TYPE_B;
					LIS->Append(d1);
				}
				LIS->RemoveCurrentElement();
			}
			else
				LIS->current =  LIS->current->next;
		}
		
		//Type B
		else
		{
			PutBit((char)s);
			if(stop==1)
				return;
			if(s==1)
			{
				if(band != 0)
				{
					if (band%3 == 1) 
					{
						maxx = (d.x-subbandxsize[band]) << 1;
						maxy = d.y << 1;
					}
					else if (band%3 == 2) 
					{
						maxx = d.x << 1;
						maxy = (d.y-subbandysize[band]) << 1;
					}
					else
					{
						maxx = (d.x-subbandxsize[band]) << 1;
						maxy = (d.y-subbandysize[band]) << 1;
					}
				
					for(j = maxy; j < maxy+2; j++) 
					{
						for(i = maxx; i < maxx+2; i++)
						{
							if(band%3 == 1)
							{
								d1.x = subbandxsize[band+3]+i;
								d1.y = j;
							}
							else if(band%3 == 2)
							{
								d1.x = i;
								d1.y = subbandysize[band+3]+j;							
							}
							else
							{
								d1.x = subbandxsize[band+3]+i;
								d1.y = subbandysize[band+3]+j;							
							}
							
							d1.type = TYPE_A;
							LIS->Append(d1);
						}						
					}
					LIS->RemoveCurrentElement();
				}

				else
				{
					if((d.x%2 != 0)&&(d.y%2 == 0))
					{
						maxx = d.x -1;					
						maxy = d.y;
						for(j = maxy; j < maxy + 2; j++)
						{
							for(i = maxx; i < maxx + 2; i++)
							{
								d1.x = subbandxsize[0]+i;
								d1.y = j;
								d1.type = TYPE_A;
								LIS->Append(d1);
							}													
						}						
					}

					if((d.x%2 == 0)&&(d.y%2 != 0))
					{
						maxx = d.x;					
						maxy = d.y -1;
						for(j = maxy; j < maxy + 2; j++)
						{
							for(i = maxx; i < maxx + 2; i++)
							{
								d1.x = i;
								d1.y = subbandysize[0]+j;
								d1.type = TYPE_A;
								LIS->Append(d1);
							}															
						}						
					}
					
					if((d.x%2 != 0)&&(d.y%2 != 0))
					{
						maxx = d.x - 1;					
						maxy = d.y - 1;
						for(j = maxy; j < maxy + 2; j++)
						{
							for(i = maxx; i < maxx + 2; i++)
							{
								d1.x = subbandxsize[0]+i;
								d1.y = subbandysize[0]+j;
								d1.type = TYPE_A;
								LIS->Append(d1);
							}										
						}
					}
					LIS->RemoveCurrentElement();
				}	
			}				
			else
				LIS->current = LIS->current->next;
		}
	}
	LIS->Reset();
	
}

void CSPIHT::RefinementPass1(CMatrix2D<ElementType> *m, int threshold)
{
   CLinkList::ListElement *p;
   int temp;
   if(pNewlyAppended==NULL)
	   return;
   p = LSP->head;
   while(p!=pNewlyAppended->next)
   {  
	  temp = threshold & abs(m->m[p->data.y][p->data.x]);
	  if(temp==0)
	     PutBit(0);
	  else
		 PutBit(1);
	  if(stop==1)
		  return;
	  p = p->next;
   }

}

void CSPIHT::Encode(ElementType *example)
{
  int threshold, pass_count;
  /*
   * Build work matrix.
   */
  header.height = nYDim;
  header.width = nXDim;
  header.BitRate = BitRate;
  header.level = level;
  header.selection = selection;
  subbands = 3*level+1;

  /*扩展后的图像大小*/
  pXDim = nXDim;/*注意赋初值*/
  pYDim = nYDim;
  if ((nXDim>>level)<<level != nXDim)
  {		
	  pXDim = ((nXDim>>level)<<level) + (1<<level);
  }
  if((nYDim>>level)<<level != nYDim)
  {
	  pYDim = ((nYDim>>level)<<level) + (1<<level);
  }  	
  
  SetSubbandSize(pXDim,pYDim);
  M = new CMatrix2D<ElementType>;
  M->Create(pYDim,pXDim);
  if (M==NULL) 
  {
	  cout << "Warning:	Failed to create matrix!\n";
	  return;
  }

  /*如果图像需要扩展，采用均值法填充像素*/
  M->LoadData(example,nYDim,nXDim,pYDim,pXDim);
  
  /*
   * Prepare output file.
   */
  int nInit = (int)(floor(log10(M->MaxMagnitude())/log10(2)));
  header.threshold = 1 << nInit;
  threshold = header.threshold;
 
  CompressedFileInfo.header = header;

  /*保持原图像的编码bit数，即：与扩展后的图像大小无关*/
  CompressedFileInfo.lCounts = int(ceil(BitRate*nXDim*nYDim/8.0));


  CompressedFileInfo.pFirstByte = new unsigned char[CompressedFileInfo.lCounts+1];

  pByte = CompressedFileInfo.pFirstByte;

  outputbyte = 0;
  mask = 0x80;
  pass_count = 0;
  stop = 0;
  zeroes = 0;
  ones = 0;

  /*
   * Do the SPIHT coding.
   */
  Initialization();

  while(threshold!=0)
  {
     pass_count++;
	 SortingPass1(M,threshold);
	 RefinementPass1(M,threshold);
     	 threshold >>= 1;
	 if(stop==1)
		 break;
  }
   DumpBuffer();
   DestroySubsize();
   
   if(cAction ==TO_DISK)
   {
	   SPIHTFile=fopen(strFileNameOut,"wb");
	   assert(SPIHTFile);
	   pByte = CompressedFileInfo.pFirstByte;
	   fwrite(&CompressedFileInfo,1,sizeof(CompressedFileInfo),SPIHTFile);
	   fwrite(pByte,1,CompressedFileInfo.lCounts,SPIHTFile);
	   fclose(SPIHTFile);
   }
   
   M->Destroy();
   LIP->Destroy();
   LIS->Destroy();
   LSP->Destroy();
}


void CSPIHT::Decode()
{
  int threshold, pass_count;

  /*
  * Read the file header.
  */
  if(cAction ==	FROM_DISK){ 
	  SPIHTFile = fopen(strFileNameIn,"rb");
	  assert(SPIHTFile);
	  fread(&CompressedFileInfo,sizeof(CSPIHTFileInfo),1,SPIHTFile);
	  header = CompressedFileInfo.header;
	  SetLevel(header.level);
	  SetBitRate(header.BitRate);
	  SetImageSize(header.width,header.height);

	  CompressedFileInfo.pFirstByte = new unsigned char[CompressedFileInfo.lCounts];
	  fread(CompressedFileInfo.pFirstByte,1,CompressedFileInfo.lCounts,SPIHTFile);
  }
  else{
  	  SetLevel(level);
	  SetBitRate(BitRate);
	  SetImageSize(nXDim,nYDim);
  }
  pByte = CompressedFileInfo.pFirstByte;
  selection = CompressedFileInfo.header.selection;