Comment convertir des traits d’encre en texte (HTML)

[ Cet article est destiné aux développeurs de Windows 8.x et Windows Phone 8.x qui créent des applications Windows Runtime. Si vous développez une application pour Windows 10, voir la Documentation ]

Découvrez comment utiliser la reconnaissance d’écriture manuscrite et convertir des traits d’encre en texte dans une application du Windows Store en JavaScript.

Mises à jour pour Windows 8.1: Dans Windows 8.1, les API d’entrée de pointeur ont fait l’objet de plusieurs mises à jour et améliorations. Pour plus d’informations, voir Modifications apportées aux API pour Windows 8.1.

Dans cet exemple, nous utilisons la fonctionnalité de reconnaissance intégrée (RecognizeAsync) de l’objet InkManager pour convertir tous les traits d’encre en texte et stocker les résultats dans le gestionnaire.

Si la reconnaissance n’est pas nécessaire, utilisez un objet InkStrokeContainer au lieu d’un objet InkManager. Les résultats de la reconnaissance précédente sont toujours disponibles via GetRecognitionResults.

Si seule la reconnaissance est nécessaire, et pas le stockage, utilisez un objet InkRecognizerContainer au lieu d’un objet InkManager.

Ce que vous devez savoir

Technologies

Prérequis

Cette procédure est basée sur Démarrage rapide : capture de données d’entrée manuscrite.

Nous partons du principe que vous savez créer une application élémentaire Windows Store en JavaScript qui utilise le modèle Bibliothèque Windows pour JavaScript.

Instructions

Étape 1: Créer un gestionnaire d’encre

Initialisez un objet InkManager chargé de traiter et de manipuler les données d’entrée manuscrite reçues du pointeur en entrée.

        // Create an ink manager.
        // InkManager is documented at https://go.microsoft.com/fwlink/?LinkID=260648.
        var inkManager = new Windows.UI.Input.Inking.InkManager();

Étape 2: Définir une langue par défaut pour la reconnaissance

Définissez la langue de reconnaissance par défaut. Pour Windows 8, chaque module linguistique inclut un jeu de langues de reconnaissance pertinentes. Pour plus d’informations sur les langues de reconnaissance valides, voir Name.

Si vous ne définissez pas la langue par défaut, le système en sélectionne une en fonction de la langue principale identifiée dans le Panneau de configuration Langue. Si la langue principale ne contient pas de langue de reconnaissance, le système utilise l’une des langues secondaires ou EN-US.

Remarque  

 

Voici comment définir la langue par défaut sur Reconnaissance d’écriture Microsoft - Anglais (États-Unis).

// Set default recognition language.
if (!setRecognizerByName("Microsoft English (US) Handwriting Recognizer")) {
    statusMessage.innerText += "\nRecognition: Failed to find English (US) recognizer.";
}
else {
    statusMessage.innerText += "\nRecognition: English (US) recognizer.";
}

Utilisez GetRecognizers afin de récupérer les langues de reconnaissance disponibles sur le système de l’utilisateur. Parcourez la liste et appelez SetDefaultRecognizer si vous trouvez la langue souhaitée. Dans le cas contraire, affichez une erreur et utilisez la langue système par défaut à la place.

/// <summary>
/// Finds a specific recognizer, and sets the inkManager's default to that recognizer.
/// Returns true if successful.
/// </summary>
/// <param name="recognizerName">The name of the handwriting recognizer.</param>
function setRecognizerByName(recognizerName) {
    try {
        // recognizers is a normal JavaScript array
        var recognizers = inkManager.getRecognizers();
        for (var i = 0, len = recognizers.length; i < len; i++) {
            if (recognizerName === recognizers[i].name) {
                inkManager.setDefaultRecognizer(recognizers[i]);
                return true;
            }
        }
    }
    catch (e) {
        displayError("setRecognizerByName: " + e.toString());
    }
    return false;
}

Étape 3: Activer la reconnaissance

Fournissez à l’utilisateur le moyen de commencer la reconnaissance.

Tout d’abord, déclarez un ensemble de boutons de mode.

<body>
<div id="applicationTitle">Ink sample</div>
<div>
    <canvas id="inkCanvas"></canvas>
    <div>
        <button id="load">Load</button>
        <button id="save">Save</button>
        <button id="draw">Draw</button>
        <button id="select">Select</button>
        <button id="selectall">Select all</button>
        <button id="erase">Erase</button>
        <button id="eraseAll">Erase all</button>
        <button id="recognize" value="selected">Handwriting recognition</button>
    </div>
</div>
<div id="modeMessage"></div>
<div id="deviceMessage"></div>
<div id="statusMessage"></div>
</body>

Déclarez ensuite un écouteur d’événements.

get("recognize").addEventListener("click", recognizeStrokes, false);

Étape 4: Traiter tous les traits

Pour finir, vous gérez la demande de reconnaissance et traitez tous les traits gérés par le gestionnaire d’encre par le biais du moteur de reconnaissance.

Pour plus de simplicité, cet exemple traite tous les traits en spécifiant un objet InkRecognitionTarget avec la valeur all. En spécifiant un objet InkRecognitionTarget avec la valeur recent, seuls les traits ajoutés depuis le dernier appel à RecognizeAsync sont traités. Ceci est particulièrement utile dans les cas où tous les traits sont traités en tant qu’écriture manuscrite et doivent être reconnus de manière dynamique en fonction d’un événement tel que pointerup, plutôt que d’une commande utilisateur. Utilisez selected pour traiter uniquement les traits sélectionnés.

/// <summary>
/// Invoked when the "Handwriting recognition" button is pressed.
/// The ink manager processes all strokes through recognizeAsync, which returns 
/// the number of words detected and a set of recognition results for each word. 
/// </summary>
/// <param name="evt">The event object.</param>
function recognizeStrokes(evt) {

    // Ensure ink strokes exist before calling recognizeAsync.
    if (inkManager.getStrokes().length > 0) {
        // recognizeAsync fails if other recognition tasks are in progress.
        try {
            // The ink manager is used to store the recognition results.
            // recognizeAsync has 3 modes: all | selected | recent.
            // For this example, we process all strokes.
            // recognizeAsync is documented at https://go.microsoft.com/fwlink/?LinkID=265172.
            inkManager.recognizeAsync(Windows.UI.Input.Inking.InkRecognitionTarget.all).done
            (
                // The recognitionResult object returned by recognizeAsync exposes the 
                // bounding rect, strokes, and text candidates for each word. 
                // In this example, we simply display the word count and recognition results.
                function (results) {
                    // recognizeAsync does not automatically update existing recognition results in the ink manager.
                    // updateRecognitionResults is documented at https://go.microsoft.com/fwlink/?LinkID=265175.
                    inkManager.updateRecognitionResults(results);

                    var x = inkManager.getRecognizers();

                    // Display the number of words returned in results.
                    statusMessage.innerText = "Words recognized: " + results.length.toString();

                    // Iterate through each word and display the ranked list of possible matches.
                    for (var i = 0; i < results.length; i++) {
                        statusMessage.innerText += "\nWord" + (i+1).toString() + ":";
                        var alts = results[i].getTextCandidates();
                        for (var j = 0; j < alts.length; j++) {
                            statusMessage.innerText += " " + alts[j].toString();
                        }
                    }
                },
                function (e) {
                    displayError("InkManager::recognizeAsync: " + e.toString());
                }
            );
        }
        catch (e) {
            displayError("recognize: " + e.toString());
        }
    }
    else {
        statusMessage.innerText = "No strokes to recognize.";
    }
}

Voir Entrée : exemple d’entrée manuscrite pour un exemple d’utilisation du rectangle englobant et des candidats de texte pour chaque mot exposé via la collection d’objets InkRecognitionResult renvoyés par RecognizeAsync. Une fois que la reconnaissance est terminée, appuyez sur un mot pour afficher une liste de candidats de texte sélectionnables dans un menu volant adjacent au mot.

Terminer l’exemple

//// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
//// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
//// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
//// PARTICULAR PURPOSE.
////
//// Copyright (c) Microsoft Corporation. All rights reserved

// Windows Store app that demonstrates the use of the Windows.UI.Input.Inking APIs.

// Ink functionality is documented at https://go.microsoft.com/fwlink/?LinkID=260649.
// User interaction functionality is documented at https://go.microsoft.com/fwlink/?LinkID=260650.
// Ink APIs are documented at https://go.microsoft.com/fwlink/?LinkID=260652.
// Pointer APIs are documented at https://go.microsoft.com/fwlink/?LinkID=260653.

(function ()
{
    "use strict";

    //
    // Global variables
    //

        // UI object references.
        var inkCanvas;
        var inkContext;
        var modeMessage;
        var deviceMessage
        var statusMessage;

        // Create an ink manager.
        // InkManager is documented at https://go.microsoft.com/fwlink/?LinkID=260648.
        var inkManager = new Windows.UI.Input.Inking.InkManager();

        // Initial pointer values.
        var pointerId = -1;
        var pointerDeviceType = null;

        // Initial stroke property values.
        var strokeColor;
        var strokeWidth;

    //
    // End global variables
    //

    // Obtain reference to the specified element.
    function get(elementId)
    {
        return document.getElementById(elementId);
    }

    function initialize()
    {
        // Set up the UI.
        inkCanvas = get("inkCanvas");
        inkContext = inkCanvas.getContext("2d");

        inkContext.lineCap = "round";
        inkContext.lineKJoin = "round";

        inkCanvas.width = window.innerWidth - 10;
        inkCanvas.height = window.innerHeight * 0.5;

        deviceMessage = get("deviceMessage");
        deviceMessage.innerText = "Undefined";
        modeMessage = get("modeMessage");
        modeMessage.innerText = inkManager.mode;
        statusMessage = get("statusMessage");
        statusMessage.innerText = "No pointer input detected."

        // Set initial ink mode.
        drawStrokes();

        // Set default recognition language.
        if (!setRecognizerByName("Microsoft English (US) Handwriting Recognizer")) {
            statusMessage.innerText += "\nRecognition: Failed to find English (US) recognizer.";
        }
        else {
            statusMessage.innerText += "\nRecognition: English (US) recognizer.";
        }

        // Set up the handlers for input processing.
        inkCanvas.addEventListener("pointerdown", onPointerDown, false);
        inkCanvas.addEventListener("pointermove", onPointerMove, false);
        inkCanvas.addEventListener("pointerup", onPointerUp, false);

        get("save").addEventListener("click", saveStrokes, false);
        get("load").addEventListener("click", loadStrokes, false);
        get("draw").addEventListener("click", drawStrokes, false);
        get("select").addEventListener("click", selectStrokes, false);
        get("selectall").addEventListener("click", selectAllStrokes, false);
        get("erase").addEventListener("click", eraseStrokes, false);
        get("eraseAll").addEventListener("click", eraseAllStrokes, false);
        get("recognize").addEventListener("click", recognizeStrokes, false);
    }
    document.addEventListener("DOMContentLoaded", initialize, false);

    function getPointerDeviceType(pId)
    {
        var pointerDeviceType;
        var pointerPoint = Windows.UI.Input.PointerPoint.getCurrentPoint(pId);
        switch (pointerPoint.pointerDevice.pointerDeviceType)
        {
            case Windows.Devices.Input.PointerDeviceType.touch:
                pointerDeviceType = "Touch";
                break;

            case Windows.Devices.Input.PointerDeviceType.pen:
                pointerDeviceType = "Pen";
                break;

            case Windows.Devices.Input.PointerDeviceType.mouse:
                pointerDeviceType = "Mouse";
                break;
            default:
                pointerDeviceType = "Undefined";
        }
        deviceMessage.innerText = pointerDeviceType;
        return pointerDeviceType;
    }

    // Occurs when the pointer (touch, pen, mouse) is detected by the canvas.
    // Each stroke begins with onPointerDown.
    function onPointerDown(evt)
    {
        // Get the device type for the pointer input.
        pointerDeviceType = getPointerDeviceType(evt.pointerId);

        // Process pen and mouse (with left button) only. Reserve touch for manipulations.
        if ((pointerDeviceType === "Pen") || ((pointerDeviceType === "Mouse") && (evt.button === 0)))
        {
            statusMessage.innerText = pointerDeviceType + " pointer down: Start stroke. "

            // Process one pointer at a time.
            if (pointerId === -1)
            {
                var current = evt.currentPoint;

                // Start drawing the stroke.
                inkContext.beginPath();
                inkContext.lineWidth = strokeWidth;
                inkContext.strokeStyle = strokeColor;

                inkContext.moveTo(current.position.x, current.position.y);

                // Add current pointer to the ink manager (begin stroke).
                inkManager.processPointerDown(current);

                // The pointer id is used to restrict input processing to the current stroke.
                pointerId = evt.pointerId;
            }
        }
        else
        {
            // Process touch input.
        }
    }

    // Mouse: Occurs when the pointer moves.
    // Pen/Touch: Occurs at a steady rate (approx. 100 messages/second) whether the pointer moves or not.
    function onPointerMove(evt)
    {
        // Process pen and mouse (with left button) only. Reserve touch for manipulations.
        if ((pointerDeviceType === "Pen") || ((pointerDeviceType === "Mouse") && (evt.button === -1)))
        {
            statusMessage.innerText = pointerDeviceType + " pointer move: Draw stroke as lines. "
            // The pointer Id is used to restrict input processing to the current stroke.
            // pointerId is updated in onPointerDown().
            if (evt.pointerId === pointerId)
            {
                var current = evt.currentPoint;

                // Draw stroke in real time.
                inkContext.lineTo(current.rawPosition.x, current.rawPosition.y);
                inkContext.stroke();

                // Add current pointer to the ink manager (update stroke).
                inkManager.processPointerUpdate(current);
            }
        }
        else
        {
            // Process touch input.
        }
    }

    // Occurs when the pointer (touch, pen, mouse) is lifted from the canvas.
    // Each stroke ends with onPointerUp.
    function onPointerUp(evt)
    {
        // Process pen and mouse (with left button) only. Reserve touch for manipulations.
        if ((pointerDeviceType === "Pen") || ((pointerDeviceType === "Mouse") && (evt.button === 0)))
        {
            statusMessage.innerText = pointerDeviceType + " pointer up: Finish stroke. "
            if (evt.pointerId === pointerId) {
                // Add current pointer to the ink manager (end stroke).
                inkManager.processPointerUp(evt.currentPoint);

                // End live drawing.
                inkContext.closePath();

                // Render strokes using bezier curves.
                renderAllStrokes();

                // Reset pointer Id.
                pointerId = -1;
            }
        }
        else
        {
            // Process touch input.
        }
    }

    // Render all strokes using bezier curves instead of line segments.
    function renderAllStrokes()
    {
        statusMessage.innerText += "Render strokes as bezier curves."

        // Clear the drawing surface of existing strokes.
        inkContext.clearRect(0, 0, inkCanvas.width, inkCanvas.height);

        // Iterate through each stroke.
        inkManager.getStrokes().forEach(
            function (stroke)
            {
                inkContext.beginPath();
                if (stroke.selected) {
                    inkContext.lineWidth = stroke.drawingAttributes.size.width * 2;
                    inkContext.strokeStyle = "green";
                } else {
                    inkContext.lineWidth = stroke.drawingAttributes.size.width;
                    inkContext.strokeStyle = "black";
                }

                // Enumerate through each line segment of the stroke.
                var first = true;

                stroke.getRenderingSegments().forEach(
                    function (segment)
                    {
                        // Move to the starting screen location of the stroke.
                        if (first)
                        {
                            inkContext.moveTo(segment.position.x, segment.position.y);
                            first = false;
                        }
                        // Calculate the bezier curve for the segment.
                        else
                        {
                            inkContext.bezierCurveTo(segment.bezierControlPoint1.x,
                                                     segment.bezierControlPoint1.y,
                                                     segment.bezierControlPoint2.x,
                                                     segment.bezierControlPoint2.y,
                                                     segment.position.x, segment.position.y);
                        }
                    }
                );
                
                // Draw the stroke.
                inkContext.stroke();
                inkContext.closePath();
            }
        );
    }

    // Set up draw mode.
    function drawStrokes() {
        inkManager.mode = Windows.UI.Input.Inking.InkManipulationMode.inking;
        strokeColor = "black";
        strokeWidth = 2;
        modeMessage.innerText = inkManager.mode;
    }

    // Set up selection mode.
    function selectStrokes() {
        inkManager.mode = Windows.UI.Input.Inking.InkManipulationMode.selecting;
        strokeColor = "red";
        strokeWidth = 1;
        modeMessage.innerText = inkManager.mode;
    }

    // Set up erase mode.
    function eraseStrokes() {
        inkManager.mode = Windows.UI.Input.Inking.InkManipulationMode.erasing;
        strokeColor = "gold";
        strokeWidth = 1;
        modeMessage.innerText = inkManager.mode;
    }

    // Select all strokes handler.
    function selectAllStrokes() {
        inkManager.mode = Windows.UI.Input.Inking.InkManipulationMode.selecting;
        strokeColor = "red";
        strokeWidth = 1;
        modeMessage.innerText = "Select all strokes.";
        // Iterate through each stroke.
        inkManager.getStrokes().forEach(
            function (stroke) {
                stroke.selected = 1;
            }
            );
        renderAllStrokes();
    }

    // Select all strokes handler.
    function eraseAllStrokes() {
        inkManager.mode = Windows.UI.Input.Inking.InkManipulationMode.inking;
        strokeColor = "black";
        strokeWidth = 2;
        modeMessage.innerText = "Erase all strokes.";
        // Iterate through each stroke.
        inkManager.getStrokes().forEach(
            function (stroke) {
                stroke.selected = 1;
            }
            );
        inkManager.deleteSelected();
        renderAllStrokes();
    }

    // Save all strokes owned by inkManager.
    function saveStrokes()
    {
        // Ensure that strokes exist before calling saveAsync.
        if (inkManager.getStrokes().size > 0)
        {
            // Set up the file save screen.
            var savePicker = Windows.Storage.Pickers.FileSavePicker();
            savePicker.suggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.picturesLibrary;
            savePicker.fileTypeChoices.insert("GIF with embedded ISF", [".gif"]);
            savePicker.defaultFileExtension = ".gif";

            // Set up the stream.
            var saveStream = null;

            // Asynchronously save the ink data to the stream.
            savePicker.pickSaveFileAsync().done(
            function (file)
            {
                if (null !== file)
                {
                    file.openAsync(Windows.Storage.FileAccessMode.readWrite).then(
                        function (stream)
                        {
                            saveStream = stream;
                            return inkManager.saveAsync(saveStream);
                        }
                    ).then(
                        function ()
                        {
                            return saveStream.flushAsync(); 
                        },
                        function (e) {
                            // Override the standard saveAsync error with our own.
                            throw new Error("saveAsync");
                        }
                    ).done(
                        function ()
                        {
                            statusMessage.innerText = "Strokes saved as GIF with embedded ISF (.gif).";
                            saveStream.close();
                        },
                        function (e) {
                            statusMessage.innerText = "Save: " + e.toString();
                            // Close the stream if open.
                            if (saveStream) {
                                saveStream.close();
                            }
                        }
                    );
                }
            }
        );
        }
        else
        {
            statusMessage.innerText = "No strokes to save.";
        }
    }

    // Load strokes into an inkManager.
    function loadStrokes()
    {
        // Set up the file open screen.
        var openPicker = Windows.Storage.Pickers.FileOpenPicker();
        openPicker.suggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.picturesLibrary;
        openPicker.fileTypeFilter.replaceAll([".gif"]);

        // Set up the stream.
        var loadStream = null;

        // Asynchronously load the ink data from the stream.
        openPicker.pickSingleFileAsync().done(
            function (file)
            {
                if (null != file)
                {
                    file.openAsync(Windows.Storage.FileAccessMode.read).then(
                        function (stream) {
                            loadStream = stream;
                            return inkManager.loadAsync(loadStream);
                        }).done(
                            function()
                            {
                                var strokes = inkManager.getStrokes().length;
                                if (strokes === 0)
                                {
                                    statusMessage.innerText = "No strokes in file.";
                                }
                                else
                                {
                                    statusMessage.innerText = strokes + " strokes loaded.";
                                }
                                renderAllStrokes();
                                loadStream.close();
                            },
                            function (e)
                            {
                                statusMessage.innerText = "Load failed.";
                                if (loadStream)
                                {
                                    // Close the stream if open.
                                    loadStream.close();
                                }
                            });
                }
            });
    }

    /// <summary>
    /// Finds a specific recognizer, and sets the inkManager's default to that recognizer.
    /// Returns true if successful.
    /// </summary>
    /// <param name="recognizerName">The name of the handwriting recognizer.</param>
    function setRecognizerByName(recognizerName) {
        try {
            // recognizers is a normal JavaScript array
            var recognizers = inkManager.getRecognizers();
            for (var i = 0, len = recognizers.length; i < len; i++) {
                if (recognizerName === recognizers[i].name) {
                    inkManager.setDefaultRecognizer(recognizers[i]);
                    return true;
                }
            }
        }
        catch (e) {
            displayError("setRecognizerByName: " + e.toString());
        }
        return false;
    }

    /// <summary>
    /// Invoked when the "Handwriting recognition" button is pressed.
    /// The ink manager processes all strokes through recognizeAsync, which returns 
    /// the number of words detected and a set of recognition results for each word. 
    /// </summary>
    /// <param name="evt">The event object.</param>
    function recognizeStrokes(evt) {

        // Ensure ink strokes exist before calling recognizeAsync.
        if (inkManager.getStrokes().length > 0) {
            // recognizeAsync fails if other recognition tasks are in progress.
            try {
                // The ink manager is used to store the recognition results.
                // recognizeAsync has 3 modes: all | selected | recent.
                // For this example, we process all strokes.
                // recognizeAsync is documented at https://go.microsoft.com/fwlink/?LinkID=265172.
                inkManager.recognizeAsync(Windows.UI.Input.Inking.InkRecognitionTarget.all).done
                (
                    // The recognitionResult object returned by recognizeAsync exposes the 
                    // bounding rect, strokes, and text candidates for each word. 
                    // In this example, we simply display the word count and recognition results.
                    function (results) {
                        // recognizeAsync does not automatically update existing recognition results in the ink manager.
                        // updateRecognitionResults is documented at https://go.microsoft.com/fwlink/?LinkID=265175.
                        inkManager.updateRecognitionResults(results);

                        var x = inkManager.getRecognizers();

                        // Display the number of words returned in results.
                        statusMessage.innerText = "Words recognized: " + results.length.toString();

                        // Iterate through each word and display the ranked list of possible matches.
                        for (var i = 0; i < results.length; i++) {
                            statusMessage.innerText += "\nWord" + (i+1).toString() + ":";
                            var alts = results[i].getTextCandidates();
                            for (var j = 0; j < alts.length; j++) {
                                statusMessage.innerText += " " + alts[j].toString();
                            }
                        }
                    },
                    function (e) {
                        displayError("InkManager::recognizeAsync: " + e.toString());
                    }
                );
            }
            catch (e) {
                displayError("recognize: " + e.toString());
            }
        }
        else {
            statusMessage.innerText = "No strokes to recognize.";
        }
    }

    // Returns true if any strokes inside the ink manager are selected; false otherwise.
    function anySelected() {
        var strokes = inkManager.getStrokes();
        var len = strokes.length;
        for (var i = 0; i < len; i++) {
            if (strokes[i].selected) {
                return true;
            }
        }
        return false;
    }



})();

Rubriques associées

Conceptuel

Réponse aux entrées effectuées à l’aide du stylo et du stylet

Démarrage rapide : capture de données d’entrée manuscrite

Référence

Windows.Devices.Input

Windows.UI.Core

Windows.UI.Input

Windows.UI.Input.Inking

Exemples (DOM)

Entrée : exemple de gestion d’événement de pointeur DOM

Exemples (API d’applications du Windows Store)

Entrée : exemple de fonctionnalités de périphériques

Entrée : exemple d’entrée manuscrite

Entrée : exemple d’entrée manuscrite simplifiée