VintaSoft Imaging .NET SDK 12.4: Documentation for .NET developer
Vintasoft.Imaging.FormsProcessing Namespace / FormRecognitionManager Class / Recognize Methods / Recognize(FormRecognitionTask) Method
Syntax Remarks Example Requirements SeeAlso
In This Topic
    Recognize(FormRecognitionTask) Method (FormRecognitionManager)
    In This Topic
    Recognizes forms in the specified image synchronously.
    Syntax
    'Declaration
    
    Public Overloads Sub Recognize( _
    ByVal task
    The task that defines parameters of forms recognition.
    As FormRecognitionTask _
    )
    public void Recognize(
    FormRecognitionTask task
    )
    public: void Recognize(
    FormRecognitionTask* task
    )
    public:
    void Recognize(
    FormRecognitionTask^ task
    )

    Parameters

    task
    The task that defines parameters of forms recognition.
    Remarks

    This method is thread-safe.

    Important! Events RecognitionStarted, RecognitionFinished, ImageRecognitionStarted, ImageRecognitionFinished and RecognitionProgress are not raised during execution of this method.
    Task events Started, Finished, ImageRecognitionStarted, ImageRecognitionFinished and Progress must be used if events are necessary.

    Forms recognition will be performed in multiple threads if MaxThreads value is greater than 1.

    Example

    This C#/VB.NET code shows how to identify and recognize a form synchronously.

    
    ''' <summary>
    ''' Recognizes single image synchronously.
    ''' </summary>
    ''' <param name="templateManager">The template manager.</param>
    ''' <param name="image">The image.</param>
    Public Shared Sub RecognizeSingleImageSync(templateManager As Vintasoft.Imaging.FormsProcessing.FormRecognition.FormTemplateManager, image As Vintasoft.Imaging.VintasoftImage)
        ' create template matching command
        Dim templateMatching As New Vintasoft.Imaging.FormsProcessing.TemplateMatching.TemplateMatchingCommand()
        ' set minimal confidence
        templateMatching.MinConfidence = 0.5F
        ' set template images
        templateMatching.TemplateImages = templateManager.TemplateImages
        ' create recognition manager
        Dim recognitionManager As New Vintasoft.Imaging.FormsProcessing.FormRecognitionManager(templateMatching, templateManager)
    
        ' if your form template contains OCR fields,
        ' make sure OCR engine manager is initialized before recognition
        ' (otherwise recognition will return null (Nothing)),
        ' see OCR field recognition examples
    
        ' subscribe to ImageRecognitionError event to output recognition errors
        AddHandler recognitionManager.ImageRecognitionError, AddressOf recognitionManager_ImageRecognitionError
    
        ' recognize the image
        Dim recognitionResult As Vintasoft.Imaging.FormsProcessing.FormRecognitionResult = recognitionManager.Recognize(image)
    
        ' unsubscribe from ImageRecognitionError event
        RemoveHandler recognitionManager.ImageRecognitionError, AddressOf recognitionManager_ImageRecognitionError
    
        ' if recognition failed with error (see ImageRecognitionError event handler output)
        If recognitionResult Is Nothing Then
            Return
        End If
    
        ' get the result of image comparison
        Dim imageCompareResult As Vintasoft.Imaging.FormsProcessing.TemplateMatching.ImageImprintCompareResult = recognitionResult.TemplateMatchingResult.ImageCompareResult
        ' if result is not reliable
        If Not imageCompareResult.IsReliable Then
            ' matching template is not found
            System.Console.WriteLine("Matching template is not found.")
        Else
            ' get recognized page
            Dim recognizedPage As Vintasoft.Imaging.FormsProcessing.FormRecognition.FormPage = recognitionResult.RecognizedPage
            ' write page info
            System.Console.WriteLine(String.Format("Matching template: {0}; confidence: {1:F1}%.", recognizedPage.Name, imageCompareResult.Confidence * 100))
    
            ' get form field count
            If recognizedPage.Items.Count = 0 Then
                System.Console.WriteLine("No form fields were recognized.")
            Else
                System.Console.WriteLine(String.Format("Recognized form field count: {0}", recognizedPage.Items.Count))
                ' for each recognized form field
                For Each recognizedField As Vintasoft.Imaging.FormsProcessing.FormRecognition.FormField In recognizedPage.Items
                    ' write field info
                    System.Console.WriteLine(String.Format("  Name: {0}; value: {1}; confidence: {2:F1}%", recognizedField.Name, recognizedField.Value, recognizedField.Confidence * 100))
                Next
            End If
        End If
    End Sub
    
    ''' <summary>
    ''' Handles the ImageRecognitionError event of the FormRecognitionManager.
    ''' </summary>
    Private Shared Sub recognitionManager_ImageRecognitionError(sender As Object, e As Vintasoft.Imaging.FormsProcessing.FormRecognitionErrorEventArgs)
        System.Console.WriteLine(e.Exception.Message)
    End Sub
    
    
    
    /// <summary>
    /// Recognizes single image synchronously.
    /// </summary>
    /// <param name="templateManager">The template manager.</param>
    /// <param name="image">The image.</param>
    public static void RecognizeSingleImageSync(
        Vintasoft.Imaging.FormsProcessing.FormRecognition.FormTemplateManager templateManager, 
        Vintasoft.Imaging.VintasoftImage image)
    {
        // create template matching command
        Vintasoft.Imaging.FormsProcessing.TemplateMatching.TemplateMatchingCommand templateMatching = 
            new Vintasoft.Imaging.FormsProcessing.TemplateMatching.TemplateMatchingCommand();
        // set minimal confidence
        templateMatching.MinConfidence = 0.5f;
        // set template images
        templateMatching.TemplateImages = templateManager.TemplateImages;
        // create recognition manager
        Vintasoft.Imaging.FormsProcessing.FormRecognitionManager recognitionManager = 
            new Vintasoft.Imaging.FormsProcessing.FormRecognitionManager(
                templateMatching, templateManager);
    
        // if your form template contains OCR fields,
        // make sure OCR engine manager is initialized before recognition
        // (otherwise recognition will return null (Nothing)),
        // see OCR field recognition examples
    
        // subscribe to ImageRecognitionError event to output recognition errors
        recognitionManager.ImageRecognitionError += recognitionManager_ImageRecognitionError;
    
        // recognize the image
        Vintasoft.Imaging.FormsProcessing.FormRecognitionResult recognitionResult = recognitionManager.Recognize(image);
    
        // unsubscribe from ImageRecognitionError event
        recognitionManager.ImageRecognitionError -= recognitionManager_ImageRecognitionError;
    
        // if recognition failed with error (see ImageRecognitionError event handler output)
        if (recognitionResult == null)
            return;
    
        // get the result of image comparison
        Vintasoft.Imaging.FormsProcessing.TemplateMatching.ImageImprintCompareResult imageCompareResult =
            recognitionResult.TemplateMatchingResult.ImageCompareResult;
        // if result is not reliable
        if (!imageCompareResult.IsReliable)
        {
            // matching template is not found
            System.Console.WriteLine("Matching template is not found.");
        }
        else
        {
            // get recognized page
            Vintasoft.Imaging.FormsProcessing.FormRecognition.FormPage recognizedPage = recognitionResult.RecognizedPage;
            // write page info
            System.Console.WriteLine(string.Format(
                "Matching template: {0}; confidence: {1:F1}%.",
                recognizedPage.Name,
                imageCompareResult.Confidence * 100));
    
            // get form field count
            if (recognizedPage.Items.Count == 0)
            {
                System.Console.WriteLine("No form fields were recognized.");
            }
            else
            {
                System.Console.WriteLine(string.Format(
                    "Recognized form field count: {0}",
                    recognizedPage.Items.Count));
                // for each recognized form field
                foreach (Vintasoft.Imaging.FormsProcessing.FormRecognition.FormField recognizedField in recognizedPage.Items)
                {
                    // write field info
                    System.Console.WriteLine(string.Format(
                        "  Name: {0}; value: {1}; confidence: {2:F1}%",
                        recognizedField.Name,
                        recognizedField.Value,
                        recognizedField.Confidence * 100));
                }
            }
        }
    }
    
    /// <summary>
    /// Handles the ImageRecognitionError event of the FormRecognitionManager.
    /// </summary>
    static void recognitionManager_ImageRecognitionError(object sender, 
        Vintasoft.Imaging.FormsProcessing.FormRecognitionErrorEventArgs e)
    {
        System.Console.WriteLine(e.Exception.Message);
    }
    
    

    Requirements

    Target Platforms: .NET 8; .NET 7; .NET 6; .NET Framework 4.8, 4.7, 4.6, 4.5, 4.0, 3.5

    See Also