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LTwain::GetJPEGCompression

Summary

Gets the current or default JPEG compression settings for the session.

Syntax

#include "ltwrappr.h"

L_INT LTwain::GetJPEGCompression (pTwJpegComp, uFlag);

Parameters

pTW_JPEGCOMPRESSION pTwJpegComp

Pointer to a TW_JPEGCOMPRESSION structure to be updated with the JPEG compression settings.

L_UINT uFlag

Flag that indicates which type of JPEG compression values to get. Possible values are:

Value	Meaning
LTWAIN_GET_JPEG_COMPRESSION	[0x0001] Get the current JPEG compression settings.
LTWAIN_GET_DEFAULT_JPEG_COMPRESSION	[0x0002] Get the default JPEG compression settings.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

This function will get the current or default TWAIN JPEG compression settings, depending on the flag passed to the uFlag parameter.

For more information about TW_JPEGCOMPRESSION, refer to the TWAIN specification.

Required DLLs and Libraries

LTTWN
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Example

L_INT LTwain__GetJPEGCompressionExample(LTwain * plTwain) 
 
{ 
   L_INT                nRet; 
   TW_JPEGCOMPRESSION   myJPEG;  
 
   memset(&myJPEG, 0, sizeof(TW_JPEGCOMPRESSION));  
 
   nRet = plTwain->GetJPEGCompression(&myJPEG, LTWAIN_GET_JPEG_COMPRESSION);  
 
   if (nRet == SUCCESS)  
 
   { 
 
      myJPEG.ColorSpace = TWPT_GRAY;  
 
      myJPEG.SubSampling = 0x10001000;  
 
      myJPEG.NumComponents = 1;  
 
      myJPEG.RestartFrequency = 0;  
 
      myJPEG.QuantMap[0] = 0;  
 
      memset(&myJPEG.QuantTable[0], 0, sizeof(TW_MEMORY));  
 
      myJPEG.HuffmanMap[0] = 0;  
 
      memset(&myJPEG.HuffmanDC[0], 0, sizeof(TW_MEMORY));  
 
      memset(&myJPEG.HuffmanAC[0], 0, sizeof(TW_MEMORY));  
 
      nRet = plTwain->SetJPEGCompression (&myJPEG, LTWAIN_SET_JPEG_COMPRESSION);  
 
      if (nRet == SUCCESS)  
 
         MessageBox(NULL, TEXT("Set JPEG compression options is success"), TEXT("Notice!"), MB_OK);  
 
      else 
 
         return nRet; 
 
   } 
   else 
      return nRet; 
 
   return SUCCESS; 
}