Using OCR and TWAIN

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The DTWAIN_AcquireFile and DTWAIN_AcquireFileEx allows an application to acquire images from a TWAIN device, and store those images as files.  One of the file types available is text (single page and multi-page).

 

The OCR engine is responsible for generating the text files.  You must select the OCR engine prior to calling DTWAIN_AcquireFile or DTWAIN_AcquireFileEx, as well as the file type that DTWAIN will use as an intermediate file when invoking the OCR engine

 

Example:

void GetOCRText( )

{

   LONG nFormats;

   int isSupported = 0;

    DTWAIN_OCRENGINE SelectedEngine;

    DTWAIN_SOURCE SelectedSource;

 

    char *filename = "MyText.txt";

 

   /* Initialize DTWAIN Library */

  DTWAIN_SysInitialize( );

 

   /* Initialize the OCR interface */

  DTWAIN_InitOCRInterface( );

 

   /* Select the default OCR engine */

    SelectedEngine = DTWAIN_SelectDefaultOCREngine( );

 

    if ( SelectedEngine != 0 )

    {

          /* assume we know that the OCR engine can process BMP files, so make sure that

              DTWAIN saves the image to a temporary BMP file for processing  */

         DTWAIN_ARRAY arr = DTWAIN_ArrayCreate(DTWAIN_ARRAYLONG, 1);

         if ( arr )

         {

             /* Set the OCR engine to process a BMP file */

            DTWAIN_ArraySetAtLong( arr, 0, DTWAIN_BMP );

            DTWAIN_SetOCRCapValues( SelectedEngine, DTWAIN_OCRCV_IMAGEFILETYPE, DTWAIN_CAPSET, arr );

            DTWAIN_ArrayDestroy( arr );

         }

 

         /* Now select the default TWAIN Source */

        SelectedEngine = DTWAIN_SelectSource( );

 

        /* return if no source was selected */

        if ( SelectedEngine == 0 )

             return;

 

        /* Start the acquisition process */

        DTWAIN_AcquireFile( SelectedSource, filename, DTWAIN_TEXT, DTWAIN_USENAME, DTWAIN_PT_BW, 1, TRUE, TRUE, NULL );

 

      /* Destroy the TWAIN interface */

      DTWAIN_SysDestroy( );

   }