Available in LEADTOOLS Imaging Pro, Vector, Document, and Medical Imaging toolkits. |
L_TwainGetJPEGCompression
#include "lttwn.h"
L_LTTWN_API L_INT L_TwainGetJPEGCompression(hSession, pTwJpegComp, uFlag)
HTWAINSESSION hSession; |
/* handle to an existing TWAIN session */ |
pTW_JPEGCOMPRESSION pTwJpegComp; |
/* pointer to a structure */ |
L_UINT uFlag; |
/* flags */ |
Gets the current or default JPEG compression settings for the session.
Parameter |
Description |
|
hSession |
Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession function. |
|
pTwJpegComp |
Pointer to a TW_JPEGCOMPRESSION structure that contains the JPEG compression settings. |
|
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
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 1.9 specification from the site "http://www.twain.org/".
This function must be called after calling the L_TwainStartCapsNeg function and before calling the L_TwainEndCapsNeg function.
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. |
See Also
Functions: |
L_TwainSetJPEGCompression, L_TwainInitSession, L_TwainStartCapsNeg |
Topics: |
Example
L_INT TwainGetJPEGCompressionExample(HTWAINSESSION hSession) { L_INT nRet; nRet = L_TwainStartCapsNeg (hSession); if(nRet != SUCCESS) return nRet; TW_JPEGCOMPRESSION myJPEG; memset(&myJPEG, 0, sizeof(TW_JPEGCOMPRESSION)); nRet = L_TwainGetJPEGCompression(hSession, &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 = L_TwainSetJPEGCompression (hSession, &myJPEG, LTWAIN_SET_JPEG_COMPRESSION); if (nRet == SUCCESS) { MessageBox(NULL, TEXT("Setting JPEG compression options was successful"), TEXT("Notice!"), MB_OK); return nRet; } } nRet = L_TwainEndCapsNeg(hSession); if(nRet != SUCCESS) return nRet; return SUCCESS; }