Nach langem tüfteln habe ich es geschaft die Bitmap zu laden und an die einzelenen Farbwerte zu kommen:

//Teste , ob die zu öffnende Datei exsistiert
		fstream file;                           
		file.open(filename, ios::in);   
		if (!file) 
		{ 
			file.close();                         
			return false;   
		} 

		//Lade das HBITMAP
		HBITMAP phBitmap;
		phBitmap = (HBITMAP)LoadImage( NULL,filename, IMAGE_BITMAP, 0, 0,
			LR_CREATEDIBSECTION | LR_DEFAULTSIZE | LR_LOADFROMFILE );

		BITMAP  bm;
		GetObject(phBitmap, sizeof(BITMAP), &bm );

		groesse =(bm.bmBitsPixel/8) * bm.bmWidth * bm.bmHeight; 
		BYTE *pBuffer = new BYTE[groesse];
		GetBitmapBits(phBitmap,groesse,  pBuffer) ;

Jetzt wollte ich zum Test einfach das Bild heller machen also

for (long x=0; x< bm.bmWidth * bmHeigh; x++) {
			if (pBuffer[x] <= 245) {pBuffer[x]=pBuffer[x]+10;			
		}

Ich habe mir auch schon im Archiv folgendes angesehen:
http://www.c-plusplus.net/forum/viewtopic-var-t-is-39400.html
Da ich aber noch nicht so viel Ahnung habe komme ich damit nicht zurecht.

Wie kann ich nun dieses Array von Farbinformationen wieder als BMP abspeichern?

Aber das mit der Datei existiert, macht man mmit [url="FileExists"]http://msdn2.microsoft.com/en-us/library/x23stk5t.aspx[/url]

mfg

PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp)
{ 
    BITMAP bmp; 
    PBITMAPINFO pbmi; 
    WORD    cClrBits; 

    // Retrieve the bitmap color format, width, and height. 
    if (!GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp)) 
	{}

    // Convert the color format to a count of bits. 
    cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel); 
    if (cClrBits == 1) 
        cClrBits = 1; 
    else if (cClrBits <= 4) 
        cClrBits = 4; 
    else if (cClrBits <= 8) 
        cClrBits = 8; 
    else if (cClrBits <= 16) 
        cClrBits = 16; 
    else if (cClrBits <= 24) 
        cClrBits = 24; 
    else cClrBits = 32; 

    // Allocate memory for the BITMAPINFO structure. (This structure 
    // contains a BITMAPINFOHEADER structure and an array of RGBQUAD 
    // data structures.) 

     if (cClrBits != 24) 
         pbmi = (PBITMAPINFO) LocalAlloc(LPTR, 
                    sizeof(BITMAPINFOHEADER) + 
                    sizeof(RGBQUAD) * (1<< cClrBits)); 

     // There is no RGBQUAD array for the 24-bit-per-pixel format. 

     else 
         pbmi = (PBITMAPINFO) LocalAlloc(LPTR, 
                    sizeof(BITMAPINFOHEADER)); 

    // Initialize the fields in the BITMAPINFO structure. 

    pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER); 
    pbmi->bmiHeader.biWidth = bmp.bmWidth; 
    pbmi->bmiHeader.biHeight = bmp.bmHeight; 
    pbmi->bmiHeader.biPlanes = bmp.bmPlanes; 
    pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel; 
    if (cClrBits < 24) 
        pbmi->bmiHeader.biClrUsed = (1<<cClrBits); 

    // If the bitmap is not compressed, set the BI_RGB flag. 
    pbmi->bmiHeader.biCompression = BI_RGB; 

    // Compute the number of bytes in the array of color 
    // indices and store the result in biSizeImage. 
    // For Windows NT, the width must be DWORD aligned unless 
    // the bitmap is RLE compressed. This example shows this. 
    // For Windows 95/98/Me, the width must be WORD aligned unless the 
    // bitmap is RLE compressed.
    pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8
                                  * pbmi->bmiHeader.biHeight; 
    // Set biClrImportant to 0, indicating that all of the 
    // device colors are important. 
     pbmi->bmiHeader.biClrImportant = 0; 
     return pbmi; 
 } 

void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, 
                  HBITMAP hBMP, HDC hDC) 
 { 
    HANDLE hf;                 // file handle 
    BITMAPFILEHEADER hdr;       // bitmap file-header 
    PBITMAPINFOHEADER pbih;     // bitmap info-header 
    LPBYTE lpBits;              // memory pointer 
    DWORD dwTotal;              // total count of bytes 
    DWORD cb;                   // incremental count of bytes 
    BYTE *hp;                   // byte pointer 
    DWORD dwTmp; 

    pbih = (PBITMAPINFOHEADER) pbi; 
    lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);

    if (!lpBits) 
	{}

    // Retrieve the color table (RGBQUAD array) and the bits 
    // (array of palette indices) from the DIB. 
    if (!GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi, 
        DIB_RGB_COLORS)) 
    {}

    // Create the .BMP file. 
    hf = CreateFile(pszFile, 
                   GENERIC_READ | GENERIC_WRITE, 
                   (DWORD) 0, 
                    NULL, 
                   CREATE_ALWAYS, 
                   FILE_ATTRIBUTE_NORMAL, 
                   (HANDLE) NULL); 
    if (hf == INVALID_HANDLE_VALUE) 
	{}
    hdr.bfType = 0x4d42;        // 0x42 = "B" 0x4d = "M" 
    // Compute the size of the entire file. 
    hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + 
                 pbih->biSize + pbih->biClrUsed 
                 * sizeof(RGBQUAD) + pbih->biSizeImage); 
    hdr.bfReserved1 = 0; 
    hdr.bfReserved2 = 0; 

    // Compute the offset to the array of color indices. 
    hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + 
                    pbih->biSize + pbih->biClrUsed 
                    * sizeof (RGBQUAD); 

    // Copy the BITMAPFILEHEADER into the .BMP file. 
    if (!WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), 
        (LPDWORD) &dwTmp,  NULL)) 
    {

    }

    // Copy the BITMAPINFOHEADER and RGBQUAD array into the file. 
    if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) 
                  + pbih->biClrUsed * sizeof (RGBQUAD), 
                  (LPDWORD) &dwTmp, ( NULL)))
	{}

    // Copy the array of color indices into the .BMP file. 
    dwTotal = cb = pbih->biSizeImage; 
    hp = lpBits; 
    if (!WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL)) 
	{}

    // Close the .BMP file. 
     if (!CloseHandle(hf)) 
	 {}

    // Free memory. 
    GlobalFree((HGLOBAL)lpBits);
}

HBITMAP ManipulateBitmap( LPCWSTR _file) 
{ 
    DWORD _width, _height; 
    HBITMAP _bitmap, DestBitmap; 
    HBITMAP newBitmap=NULL; 

    if(!_file) return NULL; 

    _bitmap= (HBITMAP)LoadImage(0,_file,IMAGE_BITMAP, 0, 0,  
                 LR_DEFAULTSIZE|LR_LOADFROMFILE|LR_CREATEDIBSECTION);   

    if(!_bitmap) return NULL; 

    BITMAP bm; 
    GetObject(_bitmap, sizeof(bm), &bm); 

    _width=bm.bmWidth; 
    _height=bm.bmHeight; 

    DestBitmap=CreateBitmapIndirect(&bm); 

    if(!_bitmap) return NULL; 

    HDC SrcDC=CreateCompatibleDC(NULL);; 
    SelectObject(SrcDC,_bitmap); 

	HDC DestDC=CreateCompatibleDC(NULL);; 
    SelectObject(DestDC,DestBitmap); 

	//Einfach nur die Pixel Kopieren
    DWORD col1; 
    for(DWORD y=0; y<_height; y++) 
	{
        for(DWORD x=0; x<_width; x++) 
        { 
			col1=GetPixel(SrcDC,x,y); 
			byte r,g,b;
			r=GetRValue(col1);
			g=GetGValue(col1);
			b=GetBValue(col1);

            SetPixel(DestDC,x,y,RGB(r,g,b)); 
        } 
	}

    DeleteDC(DestDC); 
    DeleteDC(SrcDC); 
    DeleteObject(_bitmap); 

    return DestBitmap; 
}

Ich rufe es folgendermaßen auf:
HBITMAP h=ManipulateBitmap(L"1.bmp");

CreateBMPFile(g_window->hWnd,L"test.bmp",CreateBitmapInfoStruct(g_window->hWnd,h),h,g_window->hDC);

Weiß Jemand was schief läuft?
(Die Methoden CreateBMPFile(...) und CreateBitmapInfoStruct(...) habe ich von der Microsoft Seite übernommen.

Weiß Jemand was dort falsch ist?

//Einfach nur die Pixel Kopieren
    DWORD col1; 
    for(DWORD y=0; y<_height; y++) 
	{
        for(DWORD x=0; x<_width; x++) 
        { 
			col1=GetPixel(SrcDC,x,y); 
			byte r,g,b;
			r=GetRValue(col1);
			g=GetGValue(col1);
			b=GetBValue(col1);

            SetPixel(DestDC,x,y,RGB(r,g,b)); 
        } 
	}

Weiß Jemand wo hier der Fehler ist?

DestBitmap=CreateBitmapIndirect(&bm); 

    if(!_bitmap) return NULL; 

    HDC SrcDC=CreateCompatibleDC(NULL);; 
    SelectObject(SrcDC,_bitmap); 

    HDC DestDC=CreateCompatibleDC(NULL);; 
    SelectObject(DestDC,DestBitmap);

denn wenn ich

SetPixel(ScrDC,x,y,RGB(r,g,b));

anstatt

SetPixel(DestDC,x,y,RGB(r,g,b));

benutze geht es.

Warum funktioniert das kopieren der Bitmap so nicht?