C / C++ / MFC

6-Oct-06 7:22

I have a number of images(100 or more) that need to be processed and displayed using MFC. The processing is very cpu intensive. I process the images in the main dialog, and display the result images in a child dialog, by calling the the Invalidate() and UpdateWindow() pair to redraw the child dialog after the processing of each image. And now the program is single threaded.

But the display freezes after some frames has been displayed correctly.

In the OnPaint() of the child dialog, I call this function:

void CDisplayDlg::ShowBitmap(CPaintDC *pdc, CBitmap* pBitmap)
{	
	
	BITMAP bm;
	
	pBitmap->GetBitmap(&bm);
	CDC dcMem;

	dcMem.CreateCompatibleDC(pdc);
	
	CBitmap* pOldBitmap=(CBitmap*) dcMem.SelectObject(pBitmap);
   	
	//Copy and resize the bitmap to the dialog window
	pdc->BitBlt(0,0,bm.bmWidth,bm.bmHeight,&dcMem,0,0,SRCCOPY);
	dcMem.SelectObject( pOldBitmap);
	DeleteDC(dcMem);
	
}

And this is the OnPaint():

void CDisplayDlg::OnPaint() 
{
	CPaintDC dc(this); // device context for painting
	
        // TODO: Add your message handler code here
	CFADlg *pWnd = (CFADlg *)GetParent();
	if(pWnd)
	{	
		//GDIPlusShowBitmap(&dc, &pWnd->m_bmpBitmap);
		ShowBitmap(&dc, &pWnd->m_bmpBitmap);
	}

	int m=ReleaseDC(&dc);
	TRACE("m: %d\n", m);
	// Do not call CDialog::OnPaint() for painting messages
}

After processing of all the images, the child dialog displays the last processed image. I have also tried using GDI+ to implement the showbitmap, but it has the same problem.

What should I do with this? At first I thought that was because I used up all the DC resources. Or maybe I need to use multithread it?

I will really appreciate any help from you. Thanks a lot!

-- modified at 14:21 Friday 6th October, 2006

led mike6-Oct-06 8:44

6-Oct-06 8:44

Bighand2000 wrote:
The processing is very cpu intensive.

Bighand2000 wrote:
the display freezes

Bighand2000 wrote:
maybe I need to use multithread it?

yes

led mike

Bighand20006-Oct-06 9:19

6-Oct-06 9:19

Thanks for your suggestion.

Hamid_RT6-Oct-06 8:48

Re: Image sequence display in Dialog [modified]

6-Oct-06 8:48

Did you use of thread or timer for read files because I think you read files and also you process files,right?
--------
And a question did you see PF usage on TaskManager when you run your program if you use of a wrong code then
PF usage will increase I had this problem for example It was 162MB but after run my program It was 300MB

WhiteSky

Bighand20006-Oct-06 9:22

6-Oct-06 9:22

WhiteSky wrote:
Did you use of thread or timer for read files because I think you read files and also you process files,right?
--------

I do not use any thread or timer for reading files. I just read in the image one by one, process it, display it, then write it out(this does not change anything with the display freeze problem). Generally, about 2 or 3 images can be processed each second.

-- modified at 15:29 Friday 6th October, 2006

Hamid_RT6-Oct-06 19:00

6-Oct-06 19:00

about 2 or 3 images can be processed each second if you have files with Dimensions 2331 x 3240 how long to read them?

WhiteSky

Bighand20007-Oct-06 4:29

7-Oct-06 4:29

My file is 720x480, grayscale uncompressed image( .pgm), size is about 330kB each. So it does not take much time to read.

I turned off the process step, just read in and display the images, but the display still freezes after about 100 frames(the freezing happens after about 20-50 fames when the process step is there).

Hamid_RT7-Oct-06 6:54

7-Oct-06 6:54

And after freeze what happen for your program it returns to normal state or no and one thing
did you trace your program line to line (I know Its hard) if yes what happen in this case its working or no

WhiteSky

Bighand20007-Oct-06 16:52

7-Oct-06 16:52

The calculation looks fine, since all the processed frames are written out as expected. After all the frames are done, the display is refreshed to show the last processed image.

So of all the steps for each frame: read in, process, display, write out, only display has problem: it freezes after some processed frames(maybe 20, maybe 50) are displayed.

Hamid_RT7-Oct-06 19:52

7-Oct-06 19:52

And what happen for PF usage on TaskManager? it increase or no

WhiteSky

Bighand200010-Oct-06 11:55

10-Oct-06 11:55

The PF usage is normal when the display freeze, no difference compared to when the display is ok.

I am thinking of DC resource leak. I wrote another simple program that just read in and display the images one by one, the display freeze after some images are read.

Hamid_RT10-Oct-06 18:43

Re: Image sequence display in Dialog [modified]

10-Oct-06 18:43

If you have this problem in new program how to read images?

WhiteSky

Bighand200021-Oct-06 15:37

21-Oct-06 15:37

In the programs mentioned in my previous posts under this topic, I use a CBitmap member variable to contain the images read in or processed. And I use the OnPaint of the display dialog(a separate dialog window) to display it. Every time a new image was read in or processed, the CBitmap variable was updated and Invalidate() and Redrawindow() were called to refresh the display.

Today, I discarded Invalidate() and RedrawWindow(), instead I used CClientDC and DrawImage() directly to the display dialog, and it seems the problem has been solved. But I can not move the display window and it seems the thread was too busy to response.

This is a snippet of the code:

    CClientDC dc(&m_dlgDisplay);  //m_dlgDisplay is the variable for the display dialog
Graphics graphics(dc.m_hDC);

for(int i =0; i<700; i++)
{
    //Form the image name
            strMiddle.Format(_T("%04d"), i);
    fn=strPrefix+strMiddle+_T(".jpg");

    if(m_image)
        delete m_image;
    m_image=Image::FromFile(fn);    //m_image is a Image* member varible
    graphics.DrawImage(m_image, 0, 0);
    //Sleep(30);
}

-- modified at 21:48 Saturday 21st October, 2006

Hamid_RT22-Oct-06 1:28

Elegant solution for alignment

22-Oct-06 1:28

Your code doesnt problem and thats right that you disable Sleep and also delete image if it was exist but about for wheres this loop is it possible for you to use of a thread or is it possible to use a timer instead use of for in timer you use of this code but with a difference you need to check if i=700 then killtimer and for this problem I think you have two problems first busy and second(I think)Mem usage of your program that if you move external windows on your program then if you see Mem usage of your program what happens? I research about this problem previous because I had been this problem and I know your problem you can also useof CImage classfor read files and for darw their use of BitBlt that is a member of this class
I hope it helpfuls for you but if you have any problem you can aks. Smile | :)

WhiteSky

Andre xxxxxxx6-Oct-06 7:10

Andre xxxxxxx

6-Oct-06 7:10

I've got about 200 structures which have to be byte aligned for the communication with the target over the serial port.

Currently I'm using #pragma pack and memcpy because that was the easiest solution and works well on the x86.

But the downside is that this results in misalignment and is not portable.

Writing a reader and writer for each structure would result in a lot of code and I would like port it to an ARM microcontroller where resources are limited. I also would like to avoid to use C++ and stick with C for this.

The structures contain only 8 and 16-bit members, so each members size could be represented with 1-bit.

led mike6-Oct-06 8:39

6-Oct-06 8:39

Andre Buenger wrote:
But the downside is that this results in misalignment

Where, when?

Andre Buenger wrote:
I would like port it to an ARM microcontroller

Byte alignment restrictions are processor dependent. Compilers pad based on the target processors restrictions. Byte alignment is not portable by definition. However reading/writing the same structure to/from the same processor should not be an issue.

led mike

Andre xxxxxxx6-Oct-06 9:34

Andre xxxxxxx

6-Oct-06 9:34

For the following example the sizeof(TestStruct) == 4, because there is a padding byte between the first and second member.

struct TestStruct<br />
{<br />
	char first;<br />
	short second;<br />
};<br />

If you now use a #pragma pack (1) the structure size is reduced to 3, but the second member is misaligned.

That's not a problem with a x86 processor, but the ARM processor doesn't like that.

But I've to communicate with a 16-bit NEC controller who expects the received packets to be byte-aligned. Therefore I've just pack'ed the about 200 structures so I can easily send and request them, but that is not portable.

If I now write 200 read and write functions that takes care of the alignment I end with 5000 unmaintainable error prone lines of code D'Oh! | :doh:

led mike6-Oct-06 9:37

6-Oct-06 9:37

Andre Buenger wrote:
If you now use a #pragma pack (1) the structure size is reduced to 3, but the second member is misaligned.

How is it misaligned when you told it to align on single byte? 3 would be correct. If every compiler and processor understands single byte alignment then there is no padding and therefore no "misaligned" data, right? Confused | :confused:

led mike

Andre xxxxxxx6-Oct-06 9:45

Andre xxxxxxx

6-Oct-06 9:45

You should read this article.

led mike6-Oct-06 11:03

6-Oct-06 11:03

Andre Buenger wrote:
You should read this article.

Yeah, that's what I said in my first post. Alignment is not portable by definition.

Andre Buenger wrote:
If I now write 200 read and write functions that takes care of the alignment I end with 5000 unmaintainable error prone lines of code

Yeah that does not sound fun. It seems parallel to "data transformation". Rather than write 200 functions you could use a mapping mechanism that would allow you to have a generalized routine to perform the serialization given an address and a "map". You would have a "map" instance for each structure defining the structure layout. The address of the structure instance and the associated map is used to perform serialization.

led mike

Debugger - Visualizer (VS2005) [modified]

James Brown7-Oct-06 7:04

James Brown

7-Oct-06 7:04

The most elegant solution would be to use a custom compiler, which is used to generate reader+writer functions for each of your structures.

i.e. you define your structures in a separate file:

/* core_types.h */
struct TestStruct
{
char first;
short second;
};

your project has a separate build-step which compiles core_types.h and results in:

void write_struct_TestStruct(struct TestStruct *tptr)
{
write(serial_device, tptr->first);
write(serial_device, tptr->second);
}

...and similar routines for all other types you define. Its sorta like an IDL compiler (i.e. MIDL.EXE for Windows) but designed to target your serial device instead of RPC. The idea is, all of the code to write structures is created automatically from your structure definitions so you don't have to write+maintain it by hand. Your structures stay as 'pure C' for portability.

Lots of tools are available to help you build compilers like this, google for 'lexx', 'antlr' etc. All you need is to parse a subset of 'C' - just C declarations. Maybe even the UNIX 'cdecl' program would be a good starting point.

James

http://www.catch22.net

Abyss6-Oct-06 6:33

Abyss

6-Oct-06 6:33

I'm trying to better visualise my class in the Debugger. I noticed that in VS2005 a new/great feature was introduced to help visualise containers (STL and ATL) in debugger. By this it is easy/fast to display important data from complex classes.

Unfortunately, I can't visualise one stuff. I have a class B with a member variable A* m_ptr. If I edit the autoexp.dat file \ [AutoExpand] section "B=ptr=< m_ptr, t >" then the magic "t" make sure that if the m_ptr is an instance of class C which is derived from class A the debugger displays it as ptr=[C]. This is great so far.

However I would like to do similar thing in [Visualizer] section:

A{<br />
    preview<br />
    (<br />
       #( $e.m_ptr )<br />
    )<br />
)

Since there are no official documentation for the syntax I don't know how to put the magic "t" to the preview section so the debugger will display the real instnace of the member pointer. Currently it just displays the pointer address Frown | :-(

Any idea how to do this? Or any documentation?

Many thanx,
Abyss

-- modified at 13:52 Friday 6th October, 2006

Change color of dialog border

vasmvr6-Oct-06 6:13

vasmvr

6-Oct-06 6:13

Hi all, thank in advance for your help.
I have a modeless dialog box in my form view and i'd like to color the border (the default color i black and thin), i'd like to have more thick and different color. Anyone know how to do this?

Thanks Teo

Re: Change color of dialog border

Hamid_RT19-Oct-06 8:39