Identify and recognize a document that contains only one completed form

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If you want to identify and recognize document that contains only one completed form, you need to do the following steps:

Identify a template for completed form
Recognize field values in completed form

Here is C#/VB.NET code that demonstrates how to synchronously identify and recognize a completed form.

/// <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);
}

VB.NET

''' <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

Here is C#/VB.NET code that demonstrates how to asynchronously identify and recognize a completed form.

/// <summary>
/// Recognizes single image asynchronously.
/// </summary>
/// <param name="templateManager">The template manager.</param>
/// <param name="image">The image.</param>
public static void RecognizeSingleImageAsync(
    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 = 0.6f;
    // 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

    // create recognition task
    Vintasoft.Imaging.FormsProcessing.FormRecognitionTask singleImageRecognitionTask = 
        new Vintasoft.Imaging.FormsProcessing.FormRecognitionTask(image);
    // subscribe to Finished event
    singleImageRecognitionTask.Finished += 
        new System.EventHandler(singleImageRecognitionTask_Finished);
    // subscribe to ImageRecognitionError event to output recognition errors
    singleImageRecognitionTask.ImageRecognitionError += singleImageRecognitionTask_ImageRecognitionError;
    // start recognition of the image
    recognitionManager.RecognizeAsync(singleImageRecognitionTask);
}

/// <summary>
/// Handles the Finished event of the recognition task
/// and outputs the recognition results.
/// </summary>
private static void singleImageRecognitionTask_Finished(object sender, System.EventArgs e)
{
    // get the recognition task
    Vintasoft.Imaging.FormsProcessing.FormRecognitionTask task = 
        (Vintasoft.Imaging.FormsProcessing.FormRecognitionTask)sender;
    // get the result of recognition
    Vintasoft.Imaging.FormsProcessing.FormRecognitionResult recognitionResult = task.Results[0];

    // 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 FormRecognitionTask.
/// </summary>
static void singleImageRecognitionTask_ImageRecognitionError(object sender, 
    Vintasoft.Imaging.FormsProcessing.FormRecognitionErrorEventArgs e)
{
    System.Console.WriteLine(e.Exception.Message);
}

VB.NET

''' <summary>
''' Recognizes single image asynchronously.
''' </summary>
''' <param name="templateManager">The template manager.</param>
''' <param name="image">The image.</param>
Public Shared Sub RecognizeSingleImageAsync(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 = 0.6F
    ' 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

    ' create recognition task
    Dim singleImageRecognitionTask As New Vintasoft.Imaging.FormsProcessing.FormRecognitionTask(image)
    ' subscribe to Finished event
    AddHandler singleImageRecognitionTask.Finished, New System.EventHandler(AddressOf singleImageRecognitionTask_Finished)
    ' subscribe to ImageRecognitionError event to output recognition errors
    AddHandler singleImageRecognitionTask.ImageRecognitionError, AddressOf singleImageRecognitionTask_ImageRecognitionError
    ' start recognition of the image
    recognitionManager.RecognizeAsync(singleImageRecognitionTask)
End Sub

''' <summary>
''' Handles the Finished event of the recognition task
''' and outputs the recognition results.
''' </summary>
Private Shared Sub singleImageRecognitionTask_Finished(sender As Object, e As System.EventArgs)
    ' get the recognition task
    Dim task As Vintasoft.Imaging.FormsProcessing.FormRecognitionTask = DirectCast(sender, Vintasoft.Imaging.FormsProcessing.FormRecognitionTask)
    ' get the result of recognition
    Dim recognitionResult As Vintasoft.Imaging.FormsProcessing.FormRecognitionResult = task.Results(0)

    ' 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 FormRecognitionTask.
''' </summary>
Private Shared Sub singleImageRecognitionTask_ImageRecognitionError(sender As Object, e As Vintasoft.Imaging.FormsProcessing.FormRecognitionErrorEventArgs)
    System.Console.WriteLine(e.Exception.Message)
End Sub

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