C / C++ / MFC

David Crow21-Mar-07 4:23

David Crow

21-Mar-07 4:23

prasad_som wrote:
If control is not bound to any object then it will return CWnd*, in that case is it not possible to cast it to control class(CButton for instance) and then use its functions? That may be needed some time.

Not sure why you would want to do this. I always bind each control to a CWnd object so I don't encounter such problems.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

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prasad_som21-Mar-07 7:38

prasad_som

21-Mar-07 7:38

Consider, its a check box. In this case to use SetCheck control type might needed of type CButton, I know that, SendMessage can be used in this case down casting would be appropriate, I feel. But it woould be not possible if its associated with CWnd object.

Prasad
Notifier using ATL | Operator new[],delete[][^]

David Crow21-Mar-07 7:43

David Crow

21-Mar-07 7:43

prasad_som wrote:
...I know that...

Then why even consider doing otherwise?

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

prasad_som21-Mar-07 8:00

prasad_som

21-Mar-07 8:00

DavidCrow wrote:
Then why even consider doing otherwise?

In that case, I guess using CWnd* is not needed, too. Simply work in windows handles, like good old win32 API's.

Anyway, Nice to know some new things. Smile | :)

Prasad
Notifier using ATL | Operator new[],delete[][^]

David Crow21-Mar-07 3:54

David Crow

21-Mar-07 3:54

prasad_som wrote:
CButton* pButton = dynamic_cast<cbutton*> (GetDlgItem(IDC_MY_BUTTON)); pButton->ShowWindow(SW_HIDE);

As window returned will be of type CButton in this, you need to use cast operator.

GetDlgItem() does not always return a CButton pointer. In any case, the cast is not necessary. Simply use:

CWnd* pButton = GetDlgItem(IDC_MY_BUTTON); // the ID and the variable tells you it is a button!
pButton->ShowWindow(SW_HIDE);

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Capture a menu of a Window [modified]

prasad_som20-Mar-07 20:40

prasad_som

20-Mar-07 20:40

siddharthsan wrote:
I have to hide a dialog control

ShowWindow is member of Cwnd, so should not be problem with dialog control.

Prasad
Notifier using ATL | Operator new[],delete[][^]

surajcd20-Mar-07 20:04

surajcd

20-Mar-07 20:04

Dear All,

I am working on a screen capture project.
I am facing a problem of capturing a Menu window of a specific window.
Can any one help me out for a solution?

I am using only Win32-sdk for the assignment.

Thankz in advance,

Suraj Kumar C.D

-- modified at 2:33 Wednesday 21st March, 2007

Re: Capture a menu of a Window

Michael Dunn20-Mar-07 20:26

Michael Dunn

20-Mar-07 20:26

I'd start by looking at the active accessibility (MSAA) interfaces.

--Mike--
Visual C++ MVP Cool | :cool:

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Add folder to Start Menu

kiranin20-Mar-07 19:42

kiranin

20-Mar-07 19:42

Hi ,
I want to add one of my personal folder to the start menu .
Like Recent documents it has to display documents in my personal
folder also.
how can do it?
plz Help me............

Re: Add folder to Start Menu

KaЯl21-Mar-07 1:12

KaЯl

21-Mar-07 1:12

Use Windows API (SHGetSpecialFolderPath IIRC) to get the location of the folder "Programs" and create there a subdirectory where you will create a shortcut to your documents.

Re: Add folder to Start Menu

ThatsAlok21-Mar-07 19:37

ThatsAlok

21-Mar-07 19:37

kiranin wrote:
I want to add one of my personal folder to the start menu .
Like Recent documents it has to display documents in my personal
folder also.
how can do it?

iShellLink

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Radio buttons and combo boxes

gingerballs20-Mar-07 19:35

gingerballs

20-Mar-07 19:35

Hi am an amateaur vc++ programmer.Just started now!I want to know how do i program the follwing:
i have to select an option in my combo box(a question) and the corresponding answer should appear as chioces in 3 radio buttons.Each time I select a question the option in the radio button should change.What functios should I use and where should I use?

bharathi

Re: Radio buttons and combo boxes

_AnsHUMAN_ 20-Mar-07 19:48

_AnsHUMAN_

20-Mar-07 19:48

gingerballs wrote:
i have to select an option in my combo box(a question)

CComboBox::GetCurSel() would return the index of the selected item in the combo box.
You can override the CBN_SELCHANGE message. When you get this message set the corresponding radio button as selected.
I hope that I understood you correctly...

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Re: Radio buttons and combo boxes

ThatsAlok20-Mar-07 22:25

ThatsAlok

20-Mar-07 22:25

gingerballs wrote:
Hi am an amateaur vc++ programmer.Just started now!I want to know how do i program the follwing:
i have to select an option in my combo box(a question) and the corresponding answer should appear as chioces in 3 radio buttons.Each time I select a question the option in the radio button should change.What functios should I use and where should I use?

in continuation with Anshuman... you have to you have to develop some sort of data structure which will keep you question, 3 choices and correct answer. also you have to associate the radio button with control variable of type CButton.. using CButton::SetWindowText().. you can change text of that radio at runtime when ever new question is selected!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
Global Interface Table: An Easy Way to Marshal an Interface Pointer[new]
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Image processing algorithms for extracting characters from image

JanapatiBalu20-Mar-07 19:20

Re: Image processing algorithms for extracting characters from image

20-Mar-07 19:20

Hi please help us,
We have captcha images with us, we have to remove noise and extract data present in captcha image.
Please give us suitable image processing algorithm or tell us where we can get those algorithms and give some guidance how to approach this task.

Regards,
Balu.

Russell^'20-Mar-07 23:39

Re: Image processing algorithms for extracting characters from image

20-Mar-07 23:39

It depends on the type of noise, and on what is the information that you want to extract from the image.
There is not only one type of algorithm,
often the cleaner algorithm can be slitted in more processing step (every time to remove a particular effect).
So, often, you have to write your personal algorithm.
But, of course, you can base your research on some standard processing.
Some keywords:
white noise, gaussian noise, image processing, filters, 2D filters, high pass/low pass, median, segmentation, fft, RGB/HSV image transformation,...

Cheers,
Russell

JanapatiBalu21-Mar-07 1:15

Re: Image processing algorithms for extracting characters from image

21-Mar-07 1:15

Russell,
Thanks for your reply.
The noise is nothing but in captcha image there will be vertical and horizontal line. As we all know the captcha image is generated with some irregular lines(noise) and a text on that.
I want extract the text present on the image by segmenting the image and then i have to convert it into string.

Give reply as early as possible that would help us.

Regards,
Balu.

Russell^'21-Mar-07 1:58

Re: Image processing algorithms for extracting characters from image

21-Mar-07 1:58

I think that you can use the FFT-2D.
there is a simple way to find a sample image (like a char) on a picture simply matching the FFT-2D of the sample image with the fft of the given image.
The match can be more smart if you compare not simply the fft coefficients, but some coefficients ratio:
if you normalize every coeff by the coeff(0) [at null frequency] you will obtain coefficients that are indipendent from traslations and scalatures. To understand this look at the fft properties, and what happens to the coefficients with different scale, rotations, traslation.
It surely wiil work on this type of images
http://captchas.net/logo.png

your job can became very complex if the char are distorted, you have to understand how is working the distorsion and then find a righ way to recognise the chars.
see this strage deformations
http://en.wikipedia.org/wiki/Captcha

This can give you some ideas.
http://www.adastral.ucl.ac.uk/~icox/papers/2001/TransIP01.pdf

Cheers,
Russell

JanapatiBalu21-Mar-07 2:37

Re: Image processing algorithms for extracting characters from image

21-Mar-07 2:37

Thank you Russell, i will check it out with the links u mentioned here.
Please keep mailing if any idea comes and give reply to my message, i will be great full to.
Thanks lot for your quick response.

Regards,
Balu.

JanapatiBalu21-Mar-07 2:48

Re: Image processing algorithms for extracting characters from image

21-Mar-07 2:48

Ok Russell to remove noise is complex we will keep that one aside.But how to extract characters which are in the captcha image.
One of my friend given a suggestion that we can extract data from image which is present on image using image processing algorithms.Give reply if u have any idea.

Regards,
Balu.

Russell^'21-Mar-07 3:09

Re: Image processing algorithms for extracting characters from image

21-Mar-07 3:09

The suggestion to use the FFT2D wasn't to remove the noise, but to extract char from the image.
It will work also with a low level of noise.
If the noise disturbs this processing, you can try to remove it with a pre-processing step, using some segmentation algorithm. I think that a good pre-processing is to find a good way to transform the RGB image in a monocromatic one.

Cheers,
Russell

JanapatiBalu21-Mar-07 3:35

Re: Image processing algorithms for extracting characters from image

21-Mar-07 3:35

Thanks Russell,
Your information will help us a lot.We are very much tank full to u.
I will study about FFT2D to remove noise from the image,mean while if any doubts come shall i give reply here or if any personal mail-id u will give to us we send the query to the mail id and it will be help full to us.

Regards,
Balu.

Russell^'21-Mar-07 3:42

Re: Image processing algorithms for extracting characters from image

21-Mar-07 3:42

You are wellcame
Rose | [Rose]

Cheers,
Russell

JanapatiBalu21-Mar-07 4:20