C / C++ / MFC

14-Feb-03 1:11

Can mouse hooking, then using WindowFromPoint() and ChildWindowFromPoint() help in what you want?

Enhanced MetaFile

satyavasu13-Feb-03 22:59

satyavasu

13-Feb-03 22:59

How to Rotate the EmfFile With out using SetWorldTransform?

abstracting to IDispatch

Zizilamoroso13-Feb-03 22:59

Zizilamoroso

13-Feb-03 22:59

I want to use the internet explorer inside my application. This works fine:

AtlAxWinInit();

HWND hwndChild=::CreateWindow(  "AtlAxWin",
                "Shell.Explorer.1",
                WS_CHILD|WS_VISIBLE,
                0,0,0,0,
                hwnd,NULL,
                ::GetModuleHandle(NULL),
                NULL);

IUnknown *pUnk=NULL;
AtlAxGetControl(hwndChild,&pUnk);
CComPtr<IWebBrowser2> spBrowser;
pUnk->QueryInterface(IID_IWebBrowser2,(void**)&spBrowser);
if(spBrowser)
    spBrowser->put_Visible(VARIANT_TRUE);

But, I want this to be more abstract. How can I use the interface IDispatch instead.

My attempt to abstract it, returned a DISP_E_UNKNOWNNAME while calling GetIDsOfNames with "Visible" (it IS a member of IWebBrowser2). It has to be something like that... Dead | X|

using: [VISUAL STUDIO 6.0] [WIN98/2]

Compare two bitmap

jeremysay13-Feb-03 22:55

13-Feb-03 22:55

Hello all !

I want to compare two bitmaps.I already use GetPixel() to get all pixels of bitmaps but it very very too slow (because i search bitmap in whole page).
i want to use CRC but it seems hard. you know an easy way to use CRC ?
thx in advance

User 665813-Feb-03 23:00

User 6658

13-Feb-03 23:00

You want to compare whether two bitmaps are the same? There are enough CRC classes out here on codeproject, and they are very easy to use.
Alternatively, you could try a memcmp on your loaded bitmaps, but I don't know whether this will work.

regards

modified 12-Sep-18 21:01pm.

jeremysay13-Feb-03 23:05

13-Feb-03 23:05

Gregor S. wrote:
You want to compare whether two bitmaps are the same?

yes exactly !

Gregor S. wrote:
There are enough CRC classes out here on codeproject

I have already find something but it's hard for me, I continue to seek !
thx

MAAK14-Feb-03 1:31

14-Feb-03 1:31

This is a way to do it using membmp(), might be usefull.

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;
}

I tried it with 600x600 bitmaps and worked well and with good performance.
However there is one problem, if the bitmaps are indexed and they have same bits but different color tables, they will still match as there is no comparision between the color tables here.

If you need it, it should be easy using GetDIBColorTable() function then comparing the two color tables' arrays before comparing the bits.

If you are using VC++.Net and CImage class the whole thing will be much easier.

jeremysay14-Feb-03 2:12

14-Feb-03 2:12

ok thank you for your answer !!
i'm going to try and understand your code.
i hope it is fast, because i will compare a lot of bitmap Confused | :confused:

MAAK wrote:
However there is one problem, if the bitmaps are indexed and they have same bits but different color tables, they will still match as there is no comparision between the color tables here.

all my image will have same nbr of bit, i think i will have to use

GetDIBColorTable()

thx !
I keeps you informed

MAAK14-Feb-03 2:41

14-Feb-03 2:41

Just to ensure there is no confusion. The bits I mean are the values of pixels, sorry for that term, but it's used in the BITMAP structure.

What I do mean, that if you are comparing images with true colors (24-bit color depth or more) there will be no problem, but for indexed images(16-bit, 8-bit etc) the problem of color table arise.

If all pixel values match in an indexed bitmaps that does not mean their color tables match.

I just wanted to be clearer.

jeremysay14-Feb-03 3:18

14-Feb-03 3:18

AH ok ok, sorry I had not understood !
so i shouldn't have probleme with that.

thank you to take your time to explain me.

jeremysay14-Feb-03 4:27

14-Feb-03 4:27

ok, i try your example, but i have a problem with :
if(memcmp(data1, data2, bytesize) == 0)
i have always windows error, i think it's because bytesize
you know how can i find the problem?
thx in advance

MAAK14-Feb-03 6:14

14-Feb-03 6:14

I assume that the error is a crash due to access viloation, so firstly check if either pointers are not null, this method works only with DIB bitmaps (i.e. you can't try it with bitmaps of a Client area DC or a Window DC) otherwise the pixels array is null.

If they are not null then I need to know the winodws version you use and the bitmaps dimensions and color depth to identiy the problem.

You my also try to replace the 4 with 2 in this line
DWORD bmWidthBytes = bmWidth + (4 - bmWidth % 4) * bool(bmWidth % 4);

jeremysay14-Feb-03 10:23

14-Feb-03 10:23

Thx to help me !

MAAK wrote:
I assume that the error is a crash due to access viloation
completely !

this is what i do :

1 - I do a snapshot and save the bitmap in Clipboard

  CMainFrame *pFrame = (CMainFrame*)AfxGetMainWnd();
  CChildFrame *pChild = (CChildFrame *) pFrame->GetActiveFrame();

  CRect WndRect;

      //:-D thx Schlaubi
  CWnd* pMDIClientWnd = CWnd::FromHandle(pFrame->m_hWndMDIClient);


  GetClientRect(WndRect);

  CBitmap     bitmap;
  CDC         *dcP;
  CDC         memDC;
  CRect       rect;

  dcP = GetWindowDC();
  memDC.CreateCompatibleDC(dcP);

 bitmap.CreateCompatibleBitmap(dcP,WndRect.right, WndRect.bottom);


 CBitmap *pOldBitmap = memDC.SelectObject(&bitmap);
 memDC.BitBlt(0, 0, WndRect.right,WndRect.bottom, dcP,2 , 2, SRCCOPY);

OpenClipboard();
 EmptyClipboard();

 SetClipboardData(CF_BITMAP, bitmap.GetSafeHandle());

 CloseClipboard();
 memDC.SelectObject(pOldBitmap);

2 - i want to compare tw bitmap

    HBITMAP hbmp1 = (HBITMAP) SignatureBitmap;
    HBITMAP hbmp2 = (HBITMAP) bitmap;
    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)
	AfxMessageBox("prob");
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 + (2 - bmWidth % 2) * bool(bmWidth % 2);
	//number of bytes in data1 and data2
	DWORD bytesize = bmp1.bmHeight * bmWidthBytes;
	//compare the two bitmap's bits	
	if(memcmp(data1, data2, bytesize) == 0)
		AfxMessageBox("goooooood");

	bitmap.Detach();
}

P.S : Two Bitmaps are two snapshot with few second interval (they have same confoguration).
i'm work with VC7, Windows XP with color definition 32bits.

MAAK14-Feb-03 15:13

14-Feb-03 15:13

The problem is as I expected in the previous reply. You are working with DDBs (Decive Dependent Bitmaps) and not DIB (Decive Independent Bitmaps). As far as I know there is no easy way (if exist) to get the bits of DDBs, and the BITMAP structure returned from them points to NULL memory address.

To be more clear any bitmaps got from windows DC , clients DC or any bitmaps created compatible with them are DDBs, and I think, but not sure, that they have variable size.

DIBs are the bitmaps that are normally used in file saving and it has a definit size.
More information about DDBs and DIBs

Hope you are not disappointed, but there is an easy solution, especially since you use VC++7 and have the CImage class.

All you have to do is, instead of bliting into a memory DC compatible with the window DC, you should create a CImage object and blit int it the window DC;

this is how to be get a DIB from DDB using CImage.

CDC         *dcP;
CDC         memDC;
CRect       WndRect;

dcP = GetWindowDC();
GetWindowRect(WndRect); //the window rect is the rect of the whole window
                            //while the client rect is of the client area only

CImage im; //CImage object
    //this is to create a DIB using CImage, the parameters are width, height,
    //color depth
im.Create(WndRect.Width(), WndRect.Height(), 24);
    //CImage::GetDC() return an HDC to the bitmap so you can use it
    //as any other dc
memDC.Attach(im.GetDC()); //attach the HDC into the memDC object
    //blit the window DC
memDC.BitBlt(0, 0, WndRect.right,WndRect.bottom, dcP,2 , 2, SRCCOPY);
memDC.Detach(); //detach the image HDC to prevent its destruction
im.ReleaseDC(); //this is needed for every call to GetDC()
    HBITMAP hbmp = im.Detach(); //you now have handle to DIB ready for use

The CImage is included in <atlimage.h> and please note that it needs the GDI+ runtimes. The GDI+ is inlcude in a file named gdiplus.dll, it comes already with WinXP and VS.Net, but if you are going to use it at any system other than WinXP then the DLL should be put with the application file.

For the clipboard part, copying DIBs to clipboard is more complicated than copying DDBs, you may refer to this page in the msdn, SetClipboardData Function .

However if think that you can just copy DDBs to clipboard then convert them to DIB when pasting.

I hope you are not bored from that lecture;)

jeremysay14-Feb-03 21:48

14-Feb-03 21:48

MAAK wrote:
Hope you are not disappointed

arf... a litlle bit

MAAK wrote:
HBITMAP hbmp = im.Detach(); //you now have handle to DIB ready for use
ok now i can work with hbmp and it will work fine?

i try to compare the same bitmap :

BITMAP bmp1, bmp2;

GetObject(hbmp, sizeof(hbmp), &bmp1); //get the first bitmap's data
GetObject(hbmp, sizeof(hbmp), &bmp2); //get the first bitmap's data

if(memcmp(&bmp1, &bmp2, sizeof(bmp1) - sizeof(bmp1.bmBits)))
{
    AfxMessageBox("Prob");
}
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 + (2 - bmWidth % 2) * bool(bmWidth % 2);
    //number of bytes in data1 and data2
    DWORD bytesize = bmp1.bmHeight * bmWidthBytes;
    //compare the two bitmap's bits
    if(memcmp(data1, data2, bytesize) == 0)
        AfxMessageBox("gooooooooooooooood");
}

but i have the same error Confused | :confused:

there is something which I did not understand?

MAAK14-Feb-03 23:14