bmpfile.cpp

实现了灰度图像的huffman编码,有码表的输出

// bmpfile.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "bmpfile.h"

HXLBMPFILE::HXLBMPFILE()
{
	Imagedata=NULL;

	for (int i = 0; i< 256;i++)
	{
		palette [i].rgbBlue =
		palette [i].rgbGreen = 
		palette [i].rgbRed = i;
		palette [i].rgbReserved = 0;
	}

	iRGBnum = 0;
	imagew = imageh = 0;
}

HXLBMPFILE::~HXLBMPFILE()
{
 if (Imagedata) delete Imagedata;
}

UCHAR *HXLBMPFILE::GetByteatH(int height, int RGB)
{
 if (iRGBnum <= RGB) return NULL;

 int w=imagew *height + RGB * imagew * imageh ;


 return Imagedata+w;

}

BOOL HXLBMPFILE::AllocateMem()
{	
  int w = imagew * imageh * iRGBnum;
  
	if (Imagedata)
	{
		delete Imagedata;Imagedata=NULL;
	}

	Imagedata=new BYTE [w];

	if (Imagedata) memset(Imagedata,0,w);
	return (Imagedata!=NULL);
}

BOOL HXLBMPFILE::LoadBMPFILE (char *cFilename)
{
	FILE *f;
 if (strlen(cFilename)<1) return FALSE;
 
 f=fopen(cFilename,"r+b");
 if (f==NULL) return  FALSE;

 BITMAPFILEHEADER fh;
 BITMAPINFOHEADER ih;

 fread(&fh,sizeof(BITMAPFILEHEADER),1,f);
 if (fh.bfType!=0x4d42) {fclose(f);return FALSE;}//"BM"
 
 fread (&ih,sizeof(BITMAPINFOHEADER),1,f);

 if ( (ih.biBitCount != 8)&&(ih.biBitCount != 24) ) 
 {
	 fclose (f);
	 return FALSE;
 }
 
 iRGBnum =  ih.biBitCount/8;
 imagew = ih.biWidth ;
 imageh = ih.biHeight ;

 if(!AllocateMem()) {fclose (f);return FALSE;}

 if ( iRGBnum == 1) fread (palette,sizeof(RGBQUAD),256,f);
 fseek(f,fh.bfOffBits,SEEK_SET);
 
 int w4b = (imagew * iRGBnum + 3 )/4 *4, i, j;
 BYTE *ptr;

 if (iRGBnum == 1)
 {
	 ptr = new BYTE [10];
   
    w4b -= imagew;

   for (i=imageh -1; i>=0; i--)
   {
	 fread(GetByteatH (i),imagew ,1,f);
	 if (w4b > 0) fread(ptr,w4b,1,f);
   }

   delete ptr;

 }

 if ( iRGBnum == 3)
 {

	 ptr = new BYTE [ w4b];

	 for ( i = imageh - 1; i >= 0; i--)
	 {		 
		 fread(ptr,w4b,1,f);
		 for ( j = 0; j < imagew; j++)
		 {
			 GetByteatH(i,0)[j] = ptr[j*3 + 0];
			 GetByteatH(i,1)[j] = ptr[j*3 + 1];
			 GetByteatH(i,2)[j] = ptr[j*3 + 2];
		 }
	 }

	 delete ptr;
 }

   fclose(f);
 return TRUE;
}

BOOL HXLBMPFILE::SaveBMPFILE (char *cFilename)
{
	if (!Imagedata) return FALSE;
 
 FILE *f;
 if (strlen(cFilename)<1) return  FALSE;
 f=fopen(cFilename,"w+b");
 if (f==NULL) return  FALSE;
 
 BITMAPFILEHEADER fh;
 BITMAPINFOHEADER ih;
 
  memset(&ih,0,sizeof(BITMAPINFOHEADER));

 fh.bfType = 0x4d42;
 fh.bfReserved1 = 0;
 fh.bfReserved2 = 0;
 fh.bfOffBits = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER) +( (iRGBnum == 1)?256*sizeof(RGBQUAD):0);
 ih.biWidth = imagew;
 ih.biHeight = imageh;
 ih.biSize = 40;
 ih.biPlanes = 1;
 ih.biBitCount = 8 * iRGBnum;

 int w4b = (imagew*iRGBnum  +3)/4*4;

 ih.biSizeImage = fh.bfOffBits + ih.biHeight *w4b;

 fwrite(&fh,sizeof(BITMAPFILEHEADER),1,f);
 fwrite(&ih,sizeof(BITMAPINFOHEADER),1,f);

 if ( iRGBnum == 1) fwrite(palette,sizeof(RGBQUAD),256,f);

 BYTE*	ptr;
 int i,j;

 if (iRGBnum == 1)
 {
	 ptr = new BYTE [10];

	 memset(ptr,0,10);
	 w4b -= ih.biWidth ;

	for ( i=ih.biHeight -1;i>=0;i--)
	{
		fwrite(GetByteatH(i),ih.biWidth,1,f);
		if (w4b>0) fwrite(ptr,w4b,1,f);
	}

	delete ptr;
 }

 if (iRGBnum == 3)
 {
	 ptr = new BYTE [w4b];
	 memset(ptr,0,w4b);

 	for ( i=ih.biHeight -1;i>=0;i--)
	{
		for ( j = 0; j < ih.biWidth ; j++)
		{ 
			ptr[j*3 +0 ] = GetByteatH(i,0)[j];
			ptr[j*3 +1 ] = GetByteatH(i,1)[j];
			ptr[j*3 +2 ] = GetByteatH(i,2)[j];
		}

		fwrite(ptr,w4b,1,f);
	}

	delete ptr;
 }

  fclose(f);

  return TRUE;
}