workarround with CreateDIBSection

rommi · 02-15-2009, 02:57 PM

Hi all,

i would like to scan a certain range of my desktop for a certain pixel colour
in always recurring distances. The whole should run in the background (i use WinXP
Prof) and as fast as possible. First i tried it with "GetPixel" (see the code with
GetPixel) and i could do it successfully. But the handicap is that with bigger
ranges "GetPixel" is simply to slow!

In the meantime i have read that there is a quicker possibility with "CreateDIBSection"
Now i tried to do the same work with "CreateDIBSectio" but i couldnt resovlve that
problem. Can anybody help me and give me a codesnippet that do the same work as the
GetPixel-code-example? It would be very very nice :-)

regards, rommi (C++ Beginner)

****** code with GetPixel ************

Code:

int x, y;
HDC dc = GetDC(0);
int seekpix = 16777215;

while(true)
{
   for(x=100; x < 500; x++)
   {		
	for(y=200; y < 800; y++)
	{
	   //=========== Desktop-Pixelfarbe ermitteln
	   COLORREF deskpix = GetPixel(dc, y, x);

	   //=========== Desktop-Pixelfarbe mit Suchpixel vergleich
	   if(deskpix == seekpix)
	   {
		    //execute further code
	   }
	}
   }
}

****** my try with CreateDIBSection *****

Code:

	// Deklaration
	HDC hdc_screen;
	BITMAPINFO    bmi;
	LPBYTE      pBits;
	int x=500;
	int y=800;

	// window-id
	HWND desktopHandle = GetDesktopWindow();

	// device-context
	hdc_screen = GetDC(desktopHandle);

	// clean
	ZeroMemory(&bmi, sizeof(bmi));

	// Parameter DIBSection
	bmi.bmiHeader.biSize        = sizeof(BITMAPINFOHEADER);
	bmi.bmiHeader.biWidth        = x;
	bmi.bmiHeader.biHeight        = y;
	bmi.bmiHeader.biPlanes        = 1;
	bmi.bmiHeader.biBitCount    = 24;
	bmi.bmiHeader.biCompression = BI_RGB;

	// Create DibSection	
	HBITMAP hdcBmp = CreateDIBSection(hdc_screen, &bmi, DIB_RGB_COLORS, (void **)&pBits, NULL, 0);

	// ??????
	// ??????

02-15-2009, 02:57 PM	#1
rommi Registered User Join Date: Feb 2009 Posts: 1	workarround with CreateDIBSection Hi all, i would like to scan a certain range of my desktop for a certain pixel colour in always recurring distances. The whole should run in the background (i use WinXP Prof) and as fast as possible. First i tried it with "GetPixel" (see the code with GetPixel) and i could do it successfully. But the handicap is that with bigger ranges "GetPixel" is simply to slow! In the meantime i have read that there is a quicker possibility with "CreateDIBSection" Now i tried to do the same work with "CreateDIBSectio" but i couldnt resovlve that problem. Can anybody help me and give me a codesnippet that do the same work as the GetPixel-code-example? It would be very very nice :-) regards, rommi (C++ Beginner) **** code with GetPixel ******** Code: int x, y; HDC dc = GetDC(0); int seekpix = 16777215; while(true) { for(x=100; x < 500; x++) { for(y=200; y < 800; y++) { //=========== Desktop-Pixelfarbe ermitteln COLORREF deskpix = GetPixel(dc, y, x); //=========== Desktop-Pixelfarbe mit Suchpixel vergleich if(deskpix == seekpix) { //execute further code } } } } ** my try with CreateDIBSection * Code: // Deklaration HDC hdc_screen; BITMAPINFO bmi; LPBYTE pBits; int x=500; int y=800; // window-id HWND desktopHandle = GetDesktopWindow(); // device-context hdc_screen = GetDC(desktopHandle); // clean ZeroMemory(&bmi, sizeof(bmi)); // Parameter DIBSection bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); bmi.bmiHeader.biWidth = x; bmi.bmiHeader.biHeight = y; bmi.bmiHeader.biPlanes = 1; bmi.bmiHeader.biBitCount = 24; bmi.bmiHeader.biCompression = BI_RGB; // Create DibSection HBITMAP hdcBmp = CreateDIBSection(hdc_screen, &bmi, DIB_RGB_COLORS, (void )&pBits, NULL, 0); // ?????? // ??????
rommi is offline

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
CreateDIBSection() returning NULL	arjunajay	Windows Programming	5	07-26-2006 09:54 AM
MapViewOfFile and CreateDIBSection problem with bitmaps	LuckY	Windows Programming	2	08-18-2004 08:37 AM
Loading bitmaps with createfile() +CreateDIBSection	Stevo	Windows Programming	7	05-13-2004 09:22 PM