C / C++ / MFC

        HDC dc= CreateCompatibleDC(NULL);
BITMAPINFO info;
ZeroMemory( &info.bmiHeader, sizeof (BITMAPINFOHEADER) );
info.bmiHeader.biHeight = 1002;
info.bmiHeader.biWidth = 1004;
info.bmiHeader.biPlanes = 1;
info.bmiHeader.biBitCount = 24;
info.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
info.bmiHeader.biClrUsed= 0;
info.bmiHeader.biClrImportant= 0;
long* pixels;
int Buffersize = 1004*1002;

HBITMAP hbmp= CreateDIBSection( dc,
&info,
DIB_RGB_COLORS,
(void**)&pixels,
NULL,
0 );

pixels = (long*) malloc(Buffersize*sizeof(long));
        //arr contains pixels data (32bit unsigned integers)
for(int j=0; j < Buffersize; j++)
{
    pixels[j] = arr[j];
}

int nFile = _open ("c:\\Image.bmp", _O_CREAT | _O_TRUNC | _O_BINARY | _O_WRONLY, _S_IWRITE);

int nBitmapDataSize = (width * height * 3);
int nFileSize = sizeof (BITMAPFILEHEADER) + sizeof       (BITMAPINFOHEADER) + nBitmapDataSize;
int nOffset = sizeof (BITMAPFILEHEADER) + sizeof (BITMAPINFOHEADER);

BITMAPFILEHEADER bmfh;
bmfh.bfType = ((WORD) ('M' << 8) | 'B');
bmfh.bfSize = nFileSize;
bmfh.bfReserved1 = 0;
bmfh.bfReserved2 = 0;
bmfh.bfOffBits = nOffset;

BITMAPINFOHEADER bmih;
memset (&bmih, 0, sizeof (BITMAPINFOHEADER));
bmih.biSize = sizeof (BITMAPINFOHEADER);
bmih.biPlanes = 1;
bmih.biBitCount = 24;
bmih.biCompression = BI_RGB;
bmih.biWidth = width;
bmih.biHeight = height;

_write (nFile, &bmfh, sizeof (BITMAPFILEHEADER));
_write (nFile, &bmih, sizeof (BITMAPINFOHEADER));
_write (nFile, pixels, nBitmapDataSize);
_close (nFile);