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Search found 8 results on 1 pages for 'createdibsection'.

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• CreateDIBSection is throwing, when trying to create cursor on Win

  - by Anaamika

  Hi, I am trying to create Cursor from png, and CreateDIBSection() is throwing. Follwoing is the snippet of code: HDC hdc = GetDC(NULL); void* lpBits = NULL; HBITMAP hBitmap; try { hBitmap = CreateDIBSection( hdc, (BITMAPINFO*)&bi, 0, &lpBits, NULL, (DWORD)0); } ReleaseDC(NULL, hdc); As CreateDIBSection is throwing, the code to release DC is not getting executed. can you please let me know the possible issue behind this?

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• what's the difference between GdipBitmapLockBits and CreateDIBSection

  - by Naveen

  GdipBitmapLockBits works on pBitmaps, requires locking ? CreatDIBSection gives you a DIBsection, doesn't require locking ? which method is better for working with raw pixel data ? Here are two implementations for finding the difference between two images using each method.

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• Performing full screen grab in windows

  - by Steven Lu

  I am working an idea that involves getting a full capture of the screen including windows and apps, analyzing it, and then drawing items back onto the screen, as an overlay. I want to learn image processing techniques and I could get lots of data to work with if I can directly access the Windows screen. I could use this to build automation tools the likes of which have never been seen before. More on that later. I have full screen capture working for the most part. HWND hwind = GetDesktopWindow(); HDC hdc = GetDC(hwind); int resx = GetSystemMetrics(SM_CXSCREEN); int resy = GetSystemMetrics(SM_CYSCREEN); int BitsPerPixel = GetDeviceCaps(hdc,BITSPIXEL); HDC hdc2 = CreateCompatibleDC(hdc); BITMAPINFO info; info.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); info.bmiHeader.biWidth = resx; info.bmiHeader.biHeight = resy; info.bmiHeader.biPlanes = 1; info.bmiHeader.biBitCount = BitsPerPixel; info.bmiHeader.biCompression = BI_RGB; void *data; hbitmap = CreateDIBSection(hdc2,&info,DIB_RGB_COLORS,(void**)&data,0,0); SelectObject(hdc2,hbitmap); Once this is done, I can call this repeatedly: BitBlt(hdc2,0,0,resx,resy,hdc,0,0,SRCCOPY); The cleanup code (I have no idea if this is correct): DeleteObject(hbitmap); ReleaseDC(hwind,hdc); if (hdc2) { DeleteDC(hdc2); } Every time BitBlt is called it grabs the screen and saves it in memory I can access thru data. Performance is somewhat satisfactory. BitBlt executes in 50 milliseconds (sometimes as low as 33ms) at 1920x1200x32. What surprises me is that when I switch display mode to 16 bit, 1920x1200x16, either through my graphics settings beforehand, or by using ChangeDisplaySettings, I get a massively improved screen grab time between 1ms and 2ms, which cannot be explained by the factor of two reduction in bit-depth. Using CreateDIBSection (as above) offers a significant speed up when in 16-bit mode, compared to if I set up with CreateCompatibleBitmap (6-7ms/f). Does anybody know why dropping to 16bit causes such a speed increase? Is there any hope for me to grab 32bit at such speeds? if not for the color depth, but for not forcing a change of screen buffer modes and the awful flickering.

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• CreatePatternBrush and screen color depth

  - by Carlos Alloatti

  I am creating a brush using CreatePatternBrush with a bitmap created with CreateBitmap. The bitmap is 1 pixel wide and 24 pixels tall, I have the RGB value for each pixel, so I create an array of rgbquads and pass that to CreateBitmap. This works fine when the screen color depth is 32bpp, since the bitmap I create is also 32bpp. When the screen color depth is not 32bpp, this fails, and I understand why it does, since I should be creating a compatible bitmap instead. It seems I should use CreateCompatibleBitmap instead, but how do I put the pixel data I have into that bitmap? I have also read about CreateDIBPatternBrushPt, CreateDIBitmap, CreateDIBSection, etc. I don´t understand what is a DIBSection, and find the subject generally confusing. I do understand that I need a bitmap with the same color depth as the screen, but how do I create it having only the 32bpp pixel data?

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• How to access C arrays from assembler for Windows x64?

  - by 0xdword32

  I've written an assembler function to speed up a few things for image processing (images are created with CreateDIBSection). For Win32 the assembler code works without problems, but for Win64 I get a crash as soon as I try to access my array data. I put the relevant info in a struct and my assembler function gets a pointer to this struct. The struct pointer is put into ebx/rbx and with indexing I read the data from the struct. Any idea what I am doing wrong? I use nasm together with Visual Studio 2008 and for Win64 I set "default rel". C++ code: struct myData { tUInt32 ulParam1; void* pData; }; CallMyAssemblerFunction(&myData); Assembler Code: Win32: ... push ebp; mov ebp,esp mov ebx, [ebp + 8]; pointer to our struct mov eax, [ebx]; ulParam1 mov esi, [ebx + 4]; pData, 4 byte pointer movd xmm0, [esi]; ... Win64: ... mov rbx, rcx; pointer to our struct mov eax, [rbx]; ulParam1 mov rsi, [rbx + 4]; pData, 8 byte pointer movd xmm0, [rsi]; CRASH! ...

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• How to properly recreate BITMAP, that was previously shared by CreateFileMapping()?

  - by zim22

  Dear friends, I need your help. I need to send .bmp file to another process (dialog box) and display it there, using MMF(Memory Mapped File) But the problem is that image displays in reversed colors and upside down. In first application I open picture from HDD and link it to the named MMF "Gigabyte_picture" HANDLE hFile = CreateFile("123.bmp", GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL); CreateFileMapping(hFile, NULL, PAGE_READONLY, 0, 0, "Gigabyte_picture"); In second application I open mapped bmp file and at the end I display m_HBitmap on the static component, using SendMessage function. HANDLE hMappedFile = OpenFileMapping(FILE_MAP_READ, FALSE, "Gigabyte_picture"); PBYTE pbData = (PBYTE) MapViewOfFile(hMappedFile, FILE_MAP_READ, 0, 0, 0); BITMAPINFO bmpInfo = { 0 }; LONG lBmpSize = 60608; // size of the bmp file in bytes bmpInfo.bmiHeader.biBitCount = 32; bmpInfo.bmiHeader.biHeight = 174; bmpInfo.bmiHeader.biWidth = 87; bmpInfo.bmiHeader.biPlanes = 1; bmpInfo.bmiHeader.biSizeImage = lBmpSize; bmpInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); UINT * pPixels = 0; HDC hDC = CreateCompatibleDC(NULL); HBITMAP m_HBitmap = CreateDIBSection(hDC, &bmpInfo, DIB_RGB_COLORS, (void **)& pPixels, NULL, 0); SetBitmapBits(m_HBitmap, lBmpSize, pbData); SendMessage(gStaticBox, STM_SETIMAGE, (WPARAM)IMAGE_BITMAP,(LPARAM)m_HBitmap); ///////////// HWND gStaticBox = CreateWindowEx(0, "STATIC","", SS_CENTERIMAGE | SS_REALSIZEIMAGE | SS_BITMAP | WS_CHILD | WS_VISIBLE, 10,10,380, 380, myDialog, (HMENU)-1,NULL,NULL);

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• How do you convert bytes of bitmap into x, y location of pixels?

  - by Jon

  I have a win32 program that creates a bitmap screenshot. I am trying to figure out the x and y coordinates of the bmBits. Below is the code I have so far: UINT32 nScreenX = GetSystemMetrics(SM_CXSCREEN); UINT32 nScreenY = GetSystemMetrics(SM_CYSCREEN); HDC hdc = GetDC(NULL); HDC hdcScreen = CreateCompatibleDC(hdc); HBITMAP hbmpScreen = CreateDIBSection( hdcDesk, ( BITMAPINFO* )&bitmapInfo.bmiHeader,DIB_RGB_COLORS, &bitmapDataPtr, NULL, 0 ); SelectObject(hdcScreen, hbmpScreen); BitBlt(hdcScreen, 0, 0, nScreenX , nScreenY , hdc, 0, 0, SRCCOPY); ReleaseDC(NULL, hdc); BITMAP bmpScreen; GetObject(hbmpScreen, sizeof(bmpScreen), &bmpScreen); DWORD *pScreenPixels = (DWORD*)bmpScreen.bmBits, UINT32 x = 0; UINT32 y = 0; UINT32 nCntPixels = nScreenX * nScreenY; for(int n = 0; n < nCntPixels; n++) { x = n % nScreenX; y = n / nScreenX; //do stuff with the x and y vals } The code seem correct to me but, when I use this code the x and y values appear to be off. Where does the first pixel of bmBits start? When x and y are both 0. Is that the top left, bottom left, bottom right or top right? Thanks.

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• How do I use IImgCtx to get load an image with an alpha channel?

  - by fret

  I have some working code that uses IImgCtx to load images, but I can't work out how to get at the alpha channel. For images like .gif's and .png's there are transparent pixels, but using anything other than a 24-bit bitmap as a drawing surface doesn't work. For reference on the interface: http://www.codeproject.com/KB/graphics/JianImgCtxDecoder.aspx My code looks like this: IImgCtx *Ctx = 0; HRESULT hr = CoCreateInstance(CLSID_IImgCtx, NULL, CLSCTX_INPROC_SERVER, IID_IImgCtx, (LPVOID*)&Ctx); if (SUCCEEDED(hr)) { GVariant Fn = Name; hr = Ctx->Load(Fn.WStr(), 0); if (SUCCEEDED(hr)) { SIZE Size = { -1, -1 }; ULONG State = 0; while (true) { hr = Ctx->GetStateInfo(&State, &Size, false); if (SUCCEEDED(hr)) { if ((State & IMGLOAD_COMPLETE) || (State & IMGLOAD_STOPPED) || (State & IMGLOAD_ERROR)) { break; } else { LgiSleep(1); } } else break; } if (Size.cx > 0 && Size.cy > 0 && pDC.Reset(new GMemDC)) { if (pDC->Create(Size.cx, Size.cy, 32)) { HDC hDC = pDC->StartDC(); if (hDC) { RECT rc = { 0, 0, pDC->X(), pDC->Y() }; Ctx->Draw(hDC, &rc); pDC->EndDC(); } } else pDC.Reset(); } } Ctx->Release(); Where "StartDC" basically wraps CreateCompatibleDC(NULL) and "EndDC" wraps DeleteDC, with appropriate SelectObjects for the HBITMAPS etc. And pDC-Create(x, y, bit_depth) calls CreateDIBSection(...DIB_RGB_COLORS...). So it works if I create a 24 bits/pixel bitmap but has no alpha to speak of, and it leaves the 32 bits/pixel bitmap blank. Now this interface apparently is used by Internet Explorer to load images, and obviously THAT supports transparency, so I believe that it's possible to get some level of alpha out of the interface. The question is how? (I also have fall back code that will call libpng/libjpeg/my .gif loader etc)

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