AddImageFile Method of the FRDocument Object

// Turn on the timeout in case image loading takes too long
frDocumentCallback.SetShouldTrackTime( true );
frDocumentCallback.FlushTimer();
// Call the AddImageFile method to open an image file
CheckResult( frDocument->AddImageFile( imageFilePath, 0, pageIndices ) );
// Turn off the timeout for the subsequent processing
frDocumentCallback.SetShouldTrackTime( false );
...
// Use the IFRDocumentEvents callback interface for reporting events
class CFRDocumentCallback: public IFRDocumentEvents {
public:
    CFRDocumentCallback() : startTime( 0 ) {}
 
    // Implement the IUnknown methods
    ULONG STDMETHODCALLTYPE AddRef() { return 1; }
    ULONG STDMETHODCALLTYPE Release() { return 1; }
    HRESULT STDMETHODCALLTYPE QueryInterface( REFIID riid, void** ppObject );
    HRESULT STDMETHODCALLTYPE OnProgress( IFRDocument* document, int percentage, VARIANT_BOOL* ShouldContinue );
    HRESULT STDMETHODCALLTYPE OnWarning( IFRDocument* frPage, int pageNumber, BSTR recognizerTip, 
        VARIANT_BOOL* ShouldContinue );
    HRESULT STDMETHODCALLTYPE OnPageProcessed( IFRDocument* document, int pageNumber, PageProcessingStageEnum stage );
    void FlushTimer();
    void SetShouldTrackTime( bool _shouldTrackTime );
private:
    time_t startTime;
    bool shouldTrackTime = true;
};
// Call the FlushTimer method to reset the startTime
void CFRDocumentCallback::FlushTimer() {
    time( &startTime );
}
// This callback may be used in other methods, so set shouldTrackTime to FALSE if you does not want to reset the timeout anymore 
void CFRDocumentCallback::SetShouldTrackTime( bool _shouldTrackTime ) {
    shouldTrackTime = _shouldTrackTime;
}
 
// If the difference between current time and "startTime" exсeeds a certain threshold, the process will be aborted. The AddImageFile method passes 0 
instead of percentage to the OnProgress method
HRESULT STDMETHODCALLTYPE CFRDocumentCallback::OnProgress( IFRDocument* frDocument, int percentage, 
    VARIANT_BOOL* shouldTerminate )
{
    if( shouldTrackTime ) {
        time_t currentTime;
        time( ¤tTime );
        double seconds = difftime( currentTime, startTime );
        printf( "%f\n", seconds );
        *shouldTerminate = ( seconds > 100 ? VARIANT_TRUE : VARIANT_FALSE );
    }
    return S_OK;
}