C / C++ / MFC

<code>
HBITMAP hbmp1 = NULL, hbmp2 = NULL;
BITMAP bmp1, bmp2;
..
//load the bitmaps in hbmp1 and hbmp2
..

    GetObject(hbmp1, sizeof(BITMAP), &bmp1);
//get the first bitmap's data
    GetObject(hbmp2, sizeof(BITMAP), &bmp2);
//get the first bitmap's data
//if they differ in color depth or dimenstions they mismatch
if(bmp1.bmBitsPixel != bmp2.bmBitsPixel ||	bmp1.bmHeight != bmp2.bmHeight || bmp1.bmWidth !=  bmp2.bmWidth)
	return 0;
else
{
    //get the bits of both bitmaps	
LPBYTE data1 = (LPBYTE)bmp1.bmBits,data2 = (LPBYTE)bmp2.bmBits;
    //the number of bytes per width	
DWORD bmWidth = bmp1.bmWidth * (bmp1.bmBitsPixel / 8);
    //somthing is wrong with bmWidthBytes member in Win9x and Win2k       
    //so it's better to calculate the offset yourself
DWORD bmWidthBytes = bmWidth + (4 - bmWidth % 4) * bool(bmWidth % 4);       
    //number of bytes in data1 and data2	
DWORD bytesize = bmp1.bmHeight * bmWidthBytes;
    //compare the two bitmap's bits
if(memcmp(data1, data2, bytesize) == 0)	
    return 1;
}</code>