24 True Color map to 4-bit bitmap

Be sure to note the data alignment%%%%%%%%%%%%%

BOOL cphotodlg::convert24to4 (LPCTSTR lpszsrcfile, LPCTSTR lpszdestfile)
{
FILE*FP;
fp = fopen ("Aa.txt", "WR");
Bitmapfileheader Bmhdr;
Bitmapinfoheader Bminfo;
HANDLE hfile, Hnewfile;
DWORD dwbytewritten = 0;

Open source file handle
hfile = CreateFile (Lpszsrcfile,
Generic_read,
File_share_read,
Null
Open_existing,
File_attribute_normal,
NULL);

if (hfile = = INVALID_HANDLE_VALUE)
return FALSE;
Hnewfile = CreateFile (Lpszdestfile,
generic_read| Generic_write,
file_share_read| File_share_write,
Null
Create_always,
File_attribute_normal,
NULL);
if (Hnewfile = = INVALID_HANDLE_VALUE)
{
CloseHandle (hfile);
return false;
}
Read the original file BMP headers and files Sydney city
ReadFile (hfile, &BMHDR, sizeof (BMHDR), &dwbytewritten, NULL);
ReadFile (hfile, &bminfo, sizeof (Bminfo), &dwbytewritten, NULL);
Handle only 24 bits for compressed images
if (bminfo.bibitcount!= | | | bminfo.bicompression!= 0)
{
CloseHandle (Hnewfile);
CloseHandle (hfile);
DeleteFile (Lpszdestfile);
return false;
}
Calculate image Data Size
DWORD dwoldsize = bminfo.bisizeimage;
if (dwoldsize = 0)
{
Dwoldsize = bmhdr.bfsize-sizeof (BMHDR)-sizeof (BMINFO);
}
/*
Long wid = bminfo.biwidth% 4;
if (wid > 0)
{
WID = 4-wid;
}
Wid + = Bminfo.biwidth;
*/
Long wid = Bminfo.biwidth;
Long Loldwidth = (Bminfo.biwidth * 3 +3)/4*4;
Long Lnewwidth = ((bminfo.biwidth+1)/2 +3)/4*4;
DWORD dwnewsize;
Dwnewsize = Lnewwidth *bminfo.biheight; Size of picture after conversion
Read RAW data
unsigned char *pbuffer = NULL;
pbuffer = new unsigned char[dwoldsize];
if (pbuffer = NULL)
{
CloseHandle (Hnewfile);
CloseHandle (hfile);
DeleteFile (Lpszdestfile);
return false;
}
ReadFile (hfile, pbuffer, Dwoldsize, &dwbytewritten, NULL);
Fwrite (pbuffer, dwoldsize, 1, FP);
Fclose (FP);
unsigned char *pnew = new unsigned char [dwnewsize];
unsigned char color = 0;
DWORD dwindex = 0, dwoldindex = 0;
int I, j, K;
Long pos = 0;

unsigned char R, G, B;
//
for (j = 0; J < Bminfo.biheight; J + +)
{
pos = Loldwidth * j;
for (i = 0; i< loldwidth i = i+6)
{
B = Pbuffer[pos+i];
G = pbuffer[pos+i+1];
R = pbuffer[pos+i+2];
unsigned char maxcolor = 0.299*r+0.587*g+0.114*b;
Maxcolor/= 17;
B = pbuffer[pos+i+3];
G = pbuffer[pos+i+4];
R = pbuffer[pos+i+5];
unsigned char maxcolor2 = 0.299*r+0.587*g+0.114*b;
Maxcolor2/= 17;
Pnew[j*lnewwidth + I/6] = (maxcolor<<4) |maxcolor2;
}
}
Fwrite ("------------------", sizeof ("------------------"), 1, FP);
Fwrite (Pnew, dwnewsize, 1, FP);
Fclose (FP);
/////////////////////////////////
Save the results to a new file
modifying properties
bmhdr.bfsize = sizeof (BMHDR) +sizeof (bminfo) +sizeof (rgbquad) *16 + dwnewsize;
Bmhdr.bfoffbits = bmhdr.bfsize-dwnewsize;
Bminfo.bibitcount = 4;
Bminfo.bisizeimage = dwnewsize;

 //Create palette
 rgbquad pa[16];
 unsigned char c;
 for (i = 0; i < i++)
 {
  c = i * 17;
  pa[i].rgbblue =c;
  pa[i].rgbgreen = c;
  pa[i].rgbred= C;
  pa[i].rgbreserved = 0;
 }
 //bmp Header
 writefile (hnewfile, &BMHDR, sizeof (BMHDR), &dwbytewritten, NULL);
  WriteFile (Hnewfile, &bminfo, sizeof (Bminfo), &dwbytewritten, NULL);
 writefile (Hnewfile, PA, sizeof (Rgbquad) *16, &dwbytewritten, NULL);
 writefile (Hnewfile, Pnew, Dwnewsize, &dwbytewritten, NULL);
 delete []pbuffer;
 delete []pnew;
 closehandle (Hnewfile);
 closehandle (hfile);
 return true;
}