I am trying to transfer the image in Memory mode. I need the image should be transferred in 4 bit gray scale. Even I have set the below Cap’s I am getting 8 bit gray scale bmp image. I m using XP SP3 OS, Scanner Model – fi-5120C FUJITSU.

//set image transfer mode – ICAP_XFERMECH
twCap.Cap = ICAP_XFERMECH;
twCap.ConType = TWON_ONEVALUE;
pval->ItemType = TWTY_UINT16;
pval->Item = TWSX_MEMORY; //TWSX_FILE, TWSX_MEMORY
CallTwainProc(&m_AppId,&m_Source,DG_CONTROL,DAT_CAPABILITY,MSG_SET,(TW_MEMREF)&twCap);

twCap.Cap = ICAP_PIXELTYPE;
// Set Pixel Type
twCap.ConType = TWON_ONEVALUE;
pval->ItemType = TWTY_UINT16;
pval->Item = (TW_UINT32)TWPT_GRAY; //TWPT_BW, TWPT_GRAY, TWPT_RGB
rc = CallTwainProc(&m_AppId,&m_Source,DG_CONTROL,DAT_CAPABILITY,MSG_SET,(TW_MEMREF)&twCap);

// Set Bit depth
twCap.Cap = ICAP_BITDEPTH;
twCap.ConType = TWON_ONEVALUE;
pval->ItemType = TWTY_UINT16;
pval->Item = (TW_UINT32)4; //8
rc = CallTwainProc(&m_AppId,&m_Source,DG_CONTROL,DAT_CAPABILITY,MSG_SET,(TW_MEMREF)&twCap);

Please Suggest.

Thanks,
Kannan G.