将1bpp的bmp图像存储为1bpp或者2bpp的tiff格式

// 将1bpp的位图转换为 1bit/2bit tiff
/**
参数：
  BYTE *src  二值图像的像素数据，不包含头部信息， 1bpp, 
  int src_width  原图的宽度, in pixles,
  int src_height  原图的高度, in pixles
  int bpp   转换tiff指定的bpp
*/
static BYTE *
  BW2Tif(BYTE *src, int src_width, int src_height, int bpp, DWORD& totalSize)
{
  int dst_width  = (bpp == 1) ? src_width : src_width/2;
  int dst_height = src_height;


  // get src and dst scan width
  int src_pitch = (src_width + 7)/8 + 3 & ~3; 
  int dst_pitch = (dst_width * bpp + 31)/32*4;

  // get src and dst size
  unsigned int tif_size, bmp_size;
  if(0x80000000 & dst_height)
  {
    bmp_size= src_pitch*(0 - src_height);
    tif_size = dst_pitch*(0 - dst_height);
  }
  else{
    bmp_size = src_pitch*src_height;
    tif_size = dst_pitch*dst_height;
  }

  // Image File Header
  const unsigned char tif_ifh[10]={
    'I','I',          //intel顺序
    0x2a,0x00,          //tiff版本号
    0x08,0x00,0x00,0x00,    //IFD(图形文卷目录 Image File Diretory)偏移, 8个字节
    0x0F,0x00,          // 这两个字节属于IFD了，指定有多少个Directory Entry
  };

  // Directory Entry ，每个都是12个字节的 , TIFF 6.0规定，标签要以升序的方式排列
  unsigned long tif_ifd[0x0f*3+4]={
    0x000400FE, 0x01, 0x000,    // NewSubfileType，   
    0x00030100, 0x01, 0x018,    // ImageWidth，The number of columns in the image, i.e., the number of pixels per scanline
    0x00030101, 0x01, 0x018,    // ImageLength, The number of rows (sometimes described as scanlines) in the image.

    0x00030102, 0x01, bpp,    // BitPerSample  258
    0x00030103, 0x01, 0x001,    // Compression, 1无压缩
    0x00030106, 0x01, 0x000,    // PhotometricInterpretation，  对于bilevel图像，值0=WhiteIsZero,1=BlackIsZero

    0x00040111, 0x01, 0x0CE,    // StripOffsets，For each strip, the byte offset of that strip, 
                    // N = StripsPerImage for PlanarConfiguration equal to 1; 
                    // N = SamplesPerPixel * StripsPerImage for PlanarConfiguration equal to 2
                    // 从字面上看来， StripOffsets是个数组，小于64kb,  这里是0xce, 就是头部的206个字节了
    0x00030112, 0x01, 0x001,    // Orientation
    0x00030115, 0x01, 0x001,    // SamplesPerPixel
    0x00030116, 0x01, 0xffff,   // RowsPerStrip， The number of rows in each strip (except possibly the last strip.)
    // RowsPerStrip and ImageLength together tell us the number of strips in the entire image. default is 2^32-1, 推荐每个strip是8k数据
    // image. The equation is:     StripsPerImage= floor ((ImageLength + RowsPerStrip - 1) / RowsPerStrip).
    0x00040117, 0x01, 0x07F,    // StripByteCounts

    0x0005011A, 0x01, 0x0BE,    // XResolution
    0x0005011B, 0x01, 0x0C6,    // YResolution
    0x0003011C, 0x01, 0x001,    // PlanarConfiguration ， 1是单平面格式， 2多平面格式
    0x00030128, 0x01, 0x002,    // ResolutionUnit, 0x002 = inch

    0x60031280, 0x01000000,     // X分辨率ofset=164
    0x60031280, 0x01000000,     // Y分辨率ofset=16C
  };

  //
  tif_ifd[ 5] = dst_width;
  tif_ifd[ 8] = dst_height;
  tif_ifd[29] = (tif_size + 0x0f) & 0xfffffff0;  // 简单的做成一个strip
  tif_ifd[32] = tif_size;


  // allocate dst image  hpgl
  unsigned int total_size = sizeof(tif_ifh) + sizeof(tif_ifd) + tif_size;

  TRACE1("tiff size=0x%x\n", sizeof(tif_ifh) + sizeof(tif_ifd));

  BYTE *dst =  new BYTE[total_size];
  if(NULL == dst) return FALSE;

  BYTE *curr = dst;

  totalSize = total_size;

  // 
  memcpy(curr, tif_ifh, sizeof(tif_ifh));
  curr += sizeof(tif_ifh);

  memcpy(curr, tif_ifd, sizeof(tif_ifd));
  curr += sizeof(tif_ifd);

  // 当src图像的宽度是整数个字节的时候，可以直接复制数据，如果多出几个bit，就不好搞了
  //memcpy(curr, src, tif_size);
  
  // gray2bmp_to_tif.c 中程序，是把每个像素用一个字节来存储了，而这里不是的
  // 所以不能照着写程序了
  
  int width_align = src_width & 0xffffFFF8;
  int nBytes = width_align/8;
  if (src_width - width_align)   // 有边角bit位
    nBytes += 1;

  LPBYTE src2 = src;  
  LPBYTE dst2 = curr;

  int x,y;
  for (y = 0; y < src_height; y++)
  {
    src2 = src + y * src_pitch;
    dst2 = curr + y * nBytes;    //写入tiff的数据流，不要自己补充空白数据

    memcpy(dst2, src2, nBytes);
    src2 += nBytes;
    dst2 += nBytes;
  }

  return dst;
}


// 这个是测试代码
void CPagePt::OnBnClickedButtonCv()
{

  CFileDialog fd(TRUE, _T("bmp"), NULL,  NULL,  _T("All files(*.*)|*.*|Wibdows Bitmap(*.bmp)|*.bmp||"));
  if(fd.DoModal() != IDOK)
    return;

  CString filename = fd.GetPathName();

  HBITMAP hImage = (HBITMAP)LoadImage(NULL, filename, IMAGE_BITMAP,
    0, 0, LR_LOADFROMFILE|LR_CREATEDIBSECTION|LR_DEFAULTSIZE);

  //CBitmap* m_Bitmap = CBitmap::FromHandle(hImage);

  BITMAP bm;        //获取位图信息 
  GetObject(hImage, sizeof(BITMAP), &bm); 

  // Sumit: memory allocation is still 1800x1800 in your code..
  BYTE* bmpBuffer=(BYTE*)bm.bmBits;    // GlobalAlloc(GPTR, bm.bmWidthBytes * bm.bmHeight);      //allocate memory


  DWORD tifSize;
  BYTE *tif = BW2Tif(bmpBuffer, bm.bmWidth, bm.bmHeight, 2, tifSize);

  CFile cf("C:\\bw2tif_out.tif", CFile::modeCreate | CFile::modeWrite);

  cf.Write(tif, tifSize);

  cf.Close();

  delete tif;

}