how to read an PNG file using c - C / C++ / MFC Discussion Boards

Re: Problem with GetBitmapBits() in Win32

Naveen29-Oct-07 18:52

29-Oct-07 18:52

From MSDN:

"This function is provided only for compatibility with 16-bit versions of Windows. Applications should use the GetDIBits function."

nave

[OpenedFileFinder]

Re: Problem with GetBitmapBits() in Win32

ashishbhatt29-Oct-07 19:01

ashishbhatt

29-Oct-07 19:01

But I am doing the same thing in MFC application as I have shown and i got the result then what is the problem here.

Ashish Bhatt

Re: Problem with GetBitmapBits() in Win32

Naveen29-Oct-07 19:15

Naveen

29-Oct-07 19:15

ashishbhatt wrote:
// Capture screen into bitmap
BOOL blitok = BitBlt(
m_hmemdc, rect.left - m_bmrect.left ,
rect.top - m_bmrect.top ,
rect.right - rect.left,
rect.bottom - rect.top,
m_hrootdc,
rect.left, rect.top,
SRCCOPY);

Every thing seems to be fine. But can you tell me or verify what will be position values passed to BitBlt() function like
rect.left - m_bmrect.left , rect.top - m_bmrect.top etc.

nave

[OpenedFileFinder]

Re: Problem with GetBitmapBits() in Win32

ashishbhatt29-Oct-07 19:26

ashishbhatt

29-Oct-07 19:26

Ya thanks.

here everything comes right somthing like 0,0 position and 1280,1024 position.

I hope problem is not in these value. Plz check the compatibleBitmap() and also SelectObject() function and ma I passing right bitmap handle or not.

Ashish Bhatt

Re: Problem with GetBitmapBits() in Win32

ashishbhatt29-Oct-07 19:08

ashishbhatt

29-Oct-07 19:08

Ok,So as you told to try GetDIBits(), I used it but I don't get the result.
I modified the original code as below.....

<br />
BYTE* lpClrData = (BYTE*)LocalAlloc(LPTR, datasize * sizeof(BYTE));<br />
	<br />
	if(GetDIBits(m_hmemdc,new_Bitmap,rect.right - rect.left,<br />
		rect.bottom - rect.top,lpClrData,&m_bminfo.bmi,DIB_RGB_COLORS) == 0)<br />
	{<br />
		MessageBox(NULL,CString("Failed to get Bits from DIB"),CString("TestRTMP"),0);<br />
	} <br />

Above function always return zero.So I don't get the ouotput.
Is there any other thing which I am missing in this code plz suggest me.

Thanks.

Ashish Bhatt

Re: Problem with GetBitmapBits() in Win32

Naveen29-Oct-07 20:39

Naveen

29-Oct-07 20:39

ashishbhatt wrote:
datasize = GetBitmapBits(temp_Bitmap,datasize * sizeof(COLORREF), lpClrData);

Here lies the problem

you are calling GetBitmapBits() with temp_Bitmap instead of new_Bitmap .

nave

[OpenedFileFinder]

Re: Problem with GetBitmapBits() in Win32

ashishbhatt29-Oct-07 21:42

ashishbhatt

29-Oct-07 21:42

Ya, Thanks.

But Now I am getting little much strange problem.Let me explain little much more abt my application.In my application the function in which this bitmap capture is available calls very frequently with diff diff rectangle position.

Now my problem is that at first rectangle data doesn't come(means I checked color value from the buffer it is black color for every pixel)but from second time it comes the data comes right. Every time data comes right aftere every one rectangle.

I hope it very silly mistake but i am not getting it Here I write code from which I print the Pixel values using setpixel.

<br />
<br />
unsigned char *destData = new unsigned char[iWidth*iHeight*sizeof(unsigned char *)] ;<br />
unsigned char *srcColor = new unsigned char[iWidth*iHeight*sizeof(unsigned char *)] ;<br />
	int color = 0;<br />
<br />
	for(int x = iHeight - 1; x >= 0; x--)<br />
		{<br />
			for(int y = 0; y < iWidth; y++)<br />
			{<br />
				<br />
 				srcColor[color++] = GetRValue(lpClrData[iWidth* x + y]);<br />
				srcColor[color++] = GetGValue(lpClrData[iWidth* x + y]);<br />
				srcColor[color++] = GetBValue(lpClrData[iWidth* x + y]);<br />
				<br />
				::SetPixel(m_hrootdc,x ,y ,RGB(srcColor[color-3],srcColor[color-2],srcColor[color-1])); <br />
			<br />
			}<br />
		}<br />
<br />

Ashish Bhatt

how to read an PNG file using c

googlejumbo29-Oct-07 17:49

googlejumbo

29-Oct-07 17:49

SIR,
Can u suggest an c coding for the below objective ... please help me out of this problem ..i will forward all the relevant data about the project.. Image processing
Attached is the image on which the processing is to be performed

Take this image. It is in .png format.
It has 52 characters written in it.(26 samll a b c d ………z) and 26 capital letters (A B C ………Z)

From this big image we have to segment the image into 52 small images each representing a single character.
Now we have 52 small images. Each of them represents a character.

After this on every image gabor filter is to be applied. Gabor filter is an orientation selective filter. It has some parameters by changing them we can have a set of gabor filters with different parameters.
On each character image 16 gabor filters are to be applied. This way we will have 16 output images for each image.

For all the sixteen images centroid of each image is to be found out. This will have x, y coordinates . find the normalized area of each image. Now every character has 48 components to define it (16 filter images giving 2 coordinates each and area of each output image give 16x2 +16). This can be represented in vector form.

We now have 52 vectors one vector for each image.
To test : given any 48 dimensional vector find the distance of this vector with all 52 vectors. The vector for which difference between given vector and our set of 542 vectors is least wiil be the answer. This means the given vector represents the character “ a” if suppose the difference between given vector and vector for character “a” is found to be the least.

Re: how to read an PNG file using c

Paresh Chitte29-Oct-07 18:27

Paresh Chitte

29-Oct-07 18:27

Will this[^] helpful ?

Regards,
Paresh.

how can i search an item in the MFCflexgrid?

panthal29-Oct-07 17:37

panthal

29-Oct-07 17:37

hi,
I have a msflexgrid with 2 columns and 25 rows(all with data in it) in my dialog.i'm also having a edit box in the same dialog above the flex grid.now wat i want is..if i type a name or a letter in the edit box the mouse pointer should go to that row that contains the name.

for example if i hav 2 colums(name and rollno)in msflexgrid
if i type "A" in the edit box,thn the mouse cursor should go to the row where that name column contains first letter as "A".Is there any function for getting the mouse pointer to our flexgrid?
Anybody please help mi in this regard.

thanks,
panthal

Re: how can i search an item in the MFCflexgrid?

chandu00429-Oct-07 19:44

chandu004

29-Oct-07 19:44

i think the same question is posted by you or your friend yesterday.
refer here.
http://www.codeproject.com/script/comments/forums.asp?msg=2293001&forumid=1647#xx2293001xx[^][^]

Re: how can i search an item in the MFCflexgrid?

panthal29-Oct-07 20:13

panthal

29-Oct-07 20:13

hi,
thanks chandu,
but it's not useful to me. i'am using a flexgrid and a edit box in a dialog . i have 10 row data in the flex grid.
example: first row first cell(0,0) containing data "raja"
second row first cell(1,0) containing data "panthal"

if i enter "panthal" in the edit box, the flexgrid cursor should be highlighted in the second.
is it any function to implement it?
please help me ,

Re: how can i search an item in the MFCflexgrid?

chandu00429-Oct-07 21:39

chandu004

29-Oct-07 21:39

if it is MS flex grid, then, you can set your required cell using
SetRow(row);
and
SetCol(col);
i hope you would have to explain your task step by step such that, we can understand where exactly you are stuck up.

Re: how can i search an item in the MFCflexgrid?

panthal29-Oct-07 23:07

panthal

29-Oct-07 23:07

thank u very much chandu,
your code is useful to me.

but how can i get my mouse selection to that row? (not the cursor )
and the selected row should be highlighted with a color

i'm waiting for your kind reply,

Offtopic

Nelek29-Oct-07 23:31

Nelek

29-Oct-07 23:31

Up to which MFC version is this MFCFlexGrid available?

I had to deal with the CListCtrl to make some tables and it was quite annoying at the beggining.I saw the FlexGrid in VB by a partner and was pretty easy to use but I didn't find anything in my doc (VC++ 6)

Greetings.

--------
M.D.V.

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?

Help me to understand what I'm saying, and I'll explain it better to you

Wink | ;)

Re: Offtopic

chandu00430-Oct-07 2:26

chandu004

30-Oct-07 2:26

i frequently use msflex grid in vc 6.0.
but you have to include it from components and controls into your project.
good luck.

--------------------------------------------
Suggestion to the members:
Please prefix your main thread subject with [SOLVED] if it is solved.
thanks.
chandu.

Re: Offtopic

Nelek30-Oct-07 4:01

Nelek

30-Oct-07 4:01

Ahhhmmm, so it is an extra module. I was looking for it in the VStudio 6 package D'Oh! | :doh:

ehehehe, thanks

CEdit control, how do we know if we press enter key?

Gofur Halmurat29-Oct-07 15:39

Gofur Halmurat

29-Oct-07 15:39

Hello,

How do we know if we press enter key in CEdit? is there a message? like onclick,onenterkey or something,
i searched alot about it, but i didnt find exactly what i should to do

thanks.

Re: CEdit control, how do we know if we press enter key?

Naveen29-Oct-07 16:14

Naveen

29-Oct-07 16:14

overide the pretranslate message and check the message.

BOOL MyDlg::PreTranslateMessage(MSG* pMsg) <br />
{<br />
    if( pMsg->hwnd == m_edit.m_hWnd && pMsg->message == WM_KEYDOWN && pMsg->wParam == VK_RETURN )<br />
    {<br />
            // Enter key is pressed in m_edit<br />
    }<br />
    return CDialog::PreTranslateMessage(pMsg);<br />
}

Where m_edit is the control variable of edit control.

nave

[OpenedFileFinder]

Re: CEdit control, how do we know if we press enter key?

chandu00431-Oct-07 1:35

chandu004

31-Oct-07 1:35

thanks a lot it also useful for me.

Displaying image (RAW format) on a control

Raza568029-Oct-07 13:53

Raza5680

29-Oct-07 13:53

hey..
i am using C++ (wxWindows for GUI)--I have an image file in RAW format ...i have read the file into a 2-D array, how that data is to be used display the image on a control?

thanks

Small hint dialog

Jarrah_1229-Oct-07 12:07

Jarrah_12

29-Oct-07 12:07