L_SaveFileMemory

#include "l_bitmap.h"

L_LTFIL_API L_INT L_SaveFileMemory(hHandle, pBitmap, nFormat, nBitsPerPixel, nQFactor, uFlags, pFunction, lpUserData, uSize, pSaveOptions)

Saves a bitmap to a file in memory. The output can be in any of the supported compressed or uncompressed file formats.

Returns

Comments

To use this function, do the following:

Support for 12 and 16-bit grayscale images is only available in the Document and Medical Imaging toolkits.

This function cannot be used in combination with L_RedirectIO.

This function supports signed data images, but only DICOM and TIFF formats support signed data. This function will return an error if you attempt to save a signed image to a format other than DICOM or TIFF.

For information on saving bitmaps that have been window leveled, refer to Saving Window-Leveled Bitmaps.

If the bitmap has a region, the region stored in the bitmap will be saved, if the image is saved as one of the TIFF file formats.

In LEADTOOLS version 17 and up, when saving a colored image (such as a 24-bits per pixel image) to bitonal (1-bit per pixel), the toolkit will not use any dithering when converting the image data. This is done because dithering is not the recommended when converting colored images containing text for document processing such as OCR and Barcode. The result text will be fuzzy and hard for a recognition engine to process. To save a colored image as bitonal with Floyd-Stein dithering (the behavior of LEADTOOLS 16.5 and earlier) use the ESO_USEDITHERINGMETHOD along with BITMAPHANDLE.DitheringMethod as illustrated below:

// 'pBitmap' is a colored BITMAPHANDLE
// Setup FloydStein dithering:
bitmapHandle.DitheringMethod = FLOYD_STEIN_DITHERING;
SAVEFILEOPTION saveOptions = {0};
L_GetDefaultSaveFileOption(&saveOptions, sizeof(SAVEFILEOPTION));
saveOptions.Flags |= ESO_USEDITHERINGMETHOD;
// Save the bitmap as 1-bpp with auto-dithering:
L_SaveBitmap(fileName, &bitmapHandle, FILE_CCITT_GROUP4, 1, 0, &saveOptions);
// or any other L_SaveBitmapXyz or L_SaveFileXyz functions such as:
// L_SaveFile(fileName, &bitmapHandle, FILE_CCITT_GROUP4, 1, 0, 0, NULL, NULL, &saveOptions)

Required DLLs and Libraries

Platforms

Win32, x64.

See Also

For a list of functions that utilize the LOADFILEOPTION or SAVEFILEOPTION structures, refer to Functions Utilizing the LOADFILEOPTION or SAVEFILEOPTION structures.

Example

 L_INT SaveFileMemoryExample(L_TCHAR     * pFilename,
                                           pBITMAPHANDLE pBitmapHandle,
                                           L_INT         nType,
                                           HWND          hMainWnd)
{
   UNREFERENCED_PARAMETER(nType);

   L_INT nRet;
   HANDLE  hFile=NULL;
   HANDLE hData=NULL;
   L_CHAR  *pData;
   L_CHAR  *pDataMover;
   L_SIZE_T uSize;
   SAVEFILEOPTION SaveFileOption;
   LOADFILEOPTION LoadFileOption;
   DWORD dwSizeWrite;

   L_GetDefaultSaveFileOption(&SaveFileOption, sizeof(SAVEFILEOPTION));
   L_GetDefaultLoadFileOption(&LoadFileOption, sizeof(LOADFILEOPTION));
   SaveFileOption.PageNumber = 1;

   /* save first page */
   nRet = L_SaveFileMemory (&hData, pBitmapHandle, FILE_TIF, 0, 0, 0, NULL, NULL, &uSize, &SaveFileOption);
   if(nRet != SUCCESS)
      return nRet;
    
   /* flip image */
   nRet = L_FlipBitmap(pBitmapHandle);
   if(nRet != SUCCESS)
      return nRet;
   SaveFileOption.PageNumber = 2;

   /* save second page */

   nRet = L_SaveFileMemory (&hData, pBitmapHandle, FILE_TIF, 0, 0, 0, NULL, NULL, &uSize, &SaveFileOption);
   if(nRet != SUCCESS)
      return nRet;
     
   pData = (L_CHAR  *) GlobalLock (hData);
   pDataMover = pData;

   MessageBox (NULL, TEXT("Image Saved To Memory!"), TEXT("SUCCESS"), MB_OK);
   L_FreeBitmap (pBitmapHandle);
   InvalidateRect (hMainWnd, NULL, TRUE);
   UpdateWindow (hMainWnd);
 
   /* Open/Create the file to write. */
   hFile = CreateFile(pFilename, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);

   if (hFile == INVALID_HANDLE_VALUE)
   {
      MessageBox (NULL, TEXT("Error Opening File!"), TEXT("Error"), MB_OK);
      return (FALSE); /* Failure on creation! */
   }

   /* Write the file in a loop, because the file could be larger than a single write can request. */
   while (uSize > 0)
   {
      nRet = WriteFile(hFile, pDataMover,
                      (L_INT) min (uSize, (L_UINT32) 32000), &dwSizeWrite, NULL);

      if (!nRet)
      {
         MessageBox (NULL, TEXT("Error writing file!"), TEXT("Error"), MB_OK);
         nRet = FALSE;          /* Failure on write! */
         break;
      }
      else
      {
         uSize -= dwSizeWrite;
         pDataMover += dwSizeWrite;
      }
   }

   if (nRet)
      MessageBox (NULL, TEXT("Memory File Has Been Written To Disk!"), TEXT("SUCCESS"), MB_OK);

   CloseHandle(hFile);
   GlobalUnlock (hData);
   GlobalFree (hData);

   /* load page 2 from the saved file */
   LoadFileOption.PageNumber = 2;
   if(pBitmapHandle->Flags.Allocated)
      L_FreeBitmap(pBitmapHandle);
   nRet = L_LoadBitmap (pFilename, pBitmapHandle, sizeof(BITMAPHANDLE), 0, ORDER_BGR, &LoadFileOption, NULL);
   if(nRet == SUCCESS)
   {
      InvalidateRect (hMainWnd, NULL, TRUE);
      UpdateWindow (hMainWnd);
   }
   else
   {
      MessageBox (NULL, TEXT("Error Loading from file!"), TEXT("Error"), MB_OK);
      return nRet;
   }

   return SUCCESS;
}