Image Creation using buffer memory data

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Hello all!
I'm working on a program in which, I'm receiving the bytes of an image and after storing this creating a bitmap to display.
This is my Main code Please see this..

C++

static char buff[MAX_SIZE];
	int num;
			
//receiving the bytes from a client		 
          num=recv(Socket, buff, sizeof(buff), 0);

		 
    // progress the buffer
  
				

					tagBITMAPFILEHEADER bfh = *(tagBITMAPFILEHEADER*)buff;
					tagBITMAPINFOHEADER bih = *(tagBITMAPINFOHEADER*)(buff+sizeof(tagBITMAPFILEHEADER));

					RGBQUAD             rgb = *(RGBQUAD*)(buff+sizeof(tagBITMAPFILEHEADER)+sizeof(tagBITMAPINFOHEADER));


					BITMAPINFO bi;
bi.bmiColors[0] = rgb;
bi.bmiHeader = bih;
char* pPixels = (buff+bfh.bfOffBits);

char* ppvBits;


hbitmap = CreateDIBSection(NULL, &bi, DIB_RGB_COLORS, (void**) &ppvBits, NULL, 0);
SetDIBits(NULL, hbitmap, 0, bih.biHeight, pPixels, &bi, DIB_RGB_COLORS);

GetObject(hbitmap, sizeof(BITMAP), &cBitmap);

I'm unable to create a bitmap from the data received..
I think something wrong with code.

Thanks in advance for your help!

Posted 31-Jan-13 23:50pm

Sachin k Rajput

Updated 1-Feb-13 1:18am

v3

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Comments

Matthew Faithfull 1-Feb-13 5:58am

You're going to need to indicate what is wrong in order to get some help.
Does it compile? Does it run? Do you get a result? What doesn't work?

CPallini 1-Feb-13 6:04am

And... Where is the question?

Sachin k Rajput 1-Feb-13 6:10am

its there...

On checking the bytes received,,its ok to be there from both client and server side, But my code is unable to read these bytes to create a bitmap. That's the problem. Connection is OK. Compilation is OK. Have you any idea for this code?

Sachin k Rajput 1-Feb-13 6:06am

On checking the bytes received,,its ok to be there from both client and server side,
But my code is unable to read these bytes to create a bitmap.
That's the problem.
Connection is OK.
Compilation is OK.
Have you any idea for this code?

Matthew Faithfull 1-Feb-13 6:16am

OK so I'm guessing you get a blank bitmap or one filled with rubbish?
You're offsets into the recieved data could be wrong or there could be extra headers, missing headers. If all that's wrong is the data then I'm afraid without knowing what data is in your stream I can't help further.

Sachin k Rajput 1-Feb-13 6:48am

as I've checked to receive bytes in a text file,these are bytes but there is nothing on window panel.

Matthew Faithfull 1-Feb-13 7:02am

Ah, that sounds like a display problem rather than a problem with the bitmap. You could try testing your display code separately with a bitmap you know is good, for example from a local resource. If your display code is not working of course you'll need to post that to get a fix.

Sachin k Rajput 1-Feb-13 7:14am

for WM_PAINT code is
[code]
case WM_PAINT:
{

PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd,&ps);

if(hbitmap != 0)
{

HDC hdcMem = CreateCompatibleDC(hdc);

SelectObject(hdcMem, hbitmap);

BitBlt(hdc, 10, 10, cBitmap.bmWidth, cBitmap.bmHeight, hdcMem, 0, 0, SRCCOPY);

}

EndPaint (hWnd, &ps);
}
break;
[/code]

Sachin k Rajput 1-Feb-13 7:16am

for creating a bitmap from a buffer is:
tagBITMAPFILEHEADER bfh = *(tagBITMAPFILEHEADER*)buff;
tagBITMAPINFOHEADER bih = *(tagBITMAPINFOHEADER*)(buff+sizeof(tagBITMAPFILEHEADER));

RGBQUAD rgb = *(RGBQUAD*)(buff+sizeof(tagBITMAPFILEHEADER)+sizeof(tagBITMAPINFOHEADER));

BITMAPINFO bi;
bi.bmiColors[0] = rgb;
bi.bmiHeader = bih;
char* pPixels = (buff+bfh.bfOffBits);

char* ppvBits;

hbitmap = CreateDIBSection(NULL, &bi, DIB_RGB_COLORS, (void**) &ppvBits, NULL, 0);
SetDIBits(NULL, hbitmap, 0, bih.biHeight, pPixels, &bi, DIB_RGB_COLORS);

GetObject(hbitmap, sizeof(BITMAP), &cBitmap);

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KarstenK · Answer 1 · 2013-02-10T21:58:00

Solution 1

read the docs carefully: http://msdn.microsoft.com/en-us/library/windows/desktop/dd183376(v=vs.85).aspx[^]

You better code with a clear and known sample image, and check whether the header and data are transmitted and retreived corectly.

My tip is, that the backcast goes wrong.

Posted 10-Feb-13 21:58pm

KarstenK