文字認識をして動かそう

手書き文字でロボットキットを操作します

このセクションでは、今までのブロックプログラムではなく、Html/JavaScriptを使用します。

また、Cloud Vision という、Googleが提供している画像認識サービスを利用します。

GoogleCloudApiのキーを取得する

このアプリにはGoogleCloudApiのAPIキーが必要です.

  1. Google アカウントを取得します。

  2. Google Cloud Platform のダッシュボードに行きます
    APIとサービスより,ライブラリを選択します

  3. APIライブラリの検索画面が出るのでvisionで検索します

  4. Cloud VisionAPIを選択します

  5. 有効にするボタンを押します

  6. 有効化がおわったら,APIとサービスのダッシュボードに戻り,認証情報を選択します

  7. 認証情報を作成から,APIキーを選択します

  8. 表示されたAPIキーは後々使いますので、記録しておいてください

動かしてみる

プログラムはこちらになります。
obnizIDを入力して、TestOpenを押してみましょう。

google api keyを入力する欄がありますので、先程のAPIキーを入力し、Startボタンを押すとカメラが起動します。
カメラにうまく映るように「すすめ」や「止まれ」などの文字を見せるとロボットキットもその動きをします。

<!-- HTML Example -->
<!DOCTYPE HTML>
<html>
<head>
  <meta charset="utf-8">
  <title>Video Capture Example</title>
  <meta name="viewport" content="width=device-width,initial-scale=1">
  <script src="https://obniz.io/js/jquery-3.2.1.min.js"></script>
  <script src="https://unpkg.com/obniz@2.0.2/obniz.js"></script>
    <script src="https://unpkg.com/obniz-parts-kits@0.11.2/airobot/index.js"></script>
</head>
<body>

<div id="obniz-debug"></div>

<div>
  <div class="control">
    <input type="text" id="google_api_key" placeholder="google api key" value=""/>
    <button id="startAndStop">Start</button>
  </div>
</div>
<p class="err" id="errorMessage"></p>
<div style="display:flex;">
  <video id="videoInput" autoplay playsinline width=320 height=240 style="border:1px solid;width:320px;margin-right:10px"></video>
  <canvas id="canvasOutput" width=320 height=240 style="-webkit-font-smoothing:none" hidden style="display:none"></canvas>
  <div id="log" style="border:1px solid;height: 240px;overflow-y:scroll;width:320px"></div>
</div>

<script type="text/javascript">

  let airobotkit;
  let power = 60;
  let inOperation = false;

  let mediaDevices = navigator.mediaDevices || ((navigator.mozGetUserMedia || navigator.webkitGetUserMedia || navigator.msGetUserMedia) ? {
    getUserMedia(c) {
        return new Promise(((y, n) => {
            (navigator.mozGetUserMedia || navigator.webkitGetUserMedia).call(navigator, c, y, n);
        }));
    }
} : null);

  obniz = new Obniz("OBNIZ_ID_HERE");
  obniz.onconnect = async () => {
    obniz.display.print("ready");

    airobotkit = obniz.wired("AIRobotKit",{});



  };

  function moveTo(lPower, rPower) {
    if (!airobotkit) {
      return
    }

    airobotkit.move(lPower,rPower);

  }


  let streaming = false;
  let videoInput = document.getElementById('videoInput');
  let startAndStop = document.getElementById('startAndStop');
  let canvasOutput = document.getElementById('canvasOutput');
  let canvasContext = canvasOutput.getContext('2d');

  function successCallback(stream) {
    document.getElementById("videoInput").srcObject = stream;
    onVideoStarted();
  }

  function errorCallback(err) {
    console.error('mediaDevice.getUserMedia() error:', err);
  }


  startAndStop.addEventListener('click', () => {

    if (!streaming) {

      const medias = {
        audio: false,
        video: {
          facingMode: "user"
        }
      };


      mediaDevices.getUserMedia(medias)
     .then(successCallback).catch(errorCallback);


    } else {
      onVideoStopped();
    }

  });

  function onVideoStarted() {
    streaming = true;
    startAndStop.innerText = 'Stop';
    start();
  }

  function onVideoStopped() {
    streaming = false;
    canvasContext.clearRect(0, 0, canvasOutput.width, canvasOutput.height);
    startAndStop.innerText = 'Start';
  }

  async function start() {
    const FPS = 100;

    function processVideo() {
      try {
        if (!streaming) {
          return;
        }

        let begin = Date.now();
        let base64String = capture();

        postToGoogle(base64String);

        setTimeout(processVideo, 0);
      } catch (err) {
        console.error(err);
      }
    }

    // schedule the first one.
    setTimeout(processVideo, 0);

  }

  function capture() {
    if (!streaming) {
      return null;
    }
    canvasContext.drawImage(videoInput, 0, 0, canvasOutput.width, canvasOutput.height);
    return canvasOutput.toDataURL('image/webp');
  }

  //引数はbase64形式の文字列
  function toBlob(base64) {
    var bin = atob(base64.replace(/^.*,/, ''));
    var buffer = new Uint8Array(bin.length);
    for (var i = 0; i < bin.length; i++) {
      buffer[i] = bin.charCodeAt(i);
    }
    // Blobを作成
    try {
      var blob = new Blob([buffer.buffer], {
        type: 'image/png'
      });
    } catch (e) {
      return false;
    }
    return blob;
  }

  function postToGoogle(base64Img) {
    if (inOperation) {
      return;
    }
    inOperation = true;

    var base64Img = base64Img.split(",")[1];
    var apiKey = document.getElementById("google_api_key").value;
    var body = {
      "requests": [
        {
          "image": {
            "content": base64Img
          },
          "features": [
            {
              "type": "LABEL_DETECTION"
            },
            {
              "type": "TEXT_DETECTION",
              "maxResults": 1
            }
          ]
        }
      ]
    };


    //request to google api
    fetch("https://vision.googleapis.com/v1/images:annotate?key=" + apiKey, {
      body: JSON.stringify(body),
      method: 'POST',
      headers: {
        'Content-Type': 'application/json'
      }
    }).then(function (response) {
      return response.json();
    }).then(async function (json) {
      if (isKeywordsIncludes(json.responses, ["右", "みぎ", "right"])) {
        obniz.display.clear();
        obniz.display.print("みぎ!");
        _log("右むく");
        moveTo(power, -1 * power);
      }
      else if (isKeywordsIncludes(json.responses, ["left", "左", "ひだり"])) {
        _log("左向く");
        obniz.display.clear();
        obniz.display.print("ひだり!");
        moveTo( -1 *power, power);
      }
      else if (isKeywordsIncludes(json.responses, ["stop", "止", "とまれ"])) {
        obniz.display.clear();
        obniz.display.print("ぶれーき!");
        _log("止まる");
        moveTo(0, 0);
      }
      else if (isKeywordsIncludes(json.responses, ["すすめ", "進", "go", "前", "まえ", "forward"])) {
        _log("すすむ");
        obniz.display.clear();
        obniz.display.print("まっすぐ!");
        moveTo(power, power);
      }
      else if (isKeywordsIncludes(json.responses, ["バック", "後", "back", "もどれ", "もどる"])) {
        _log("もどる");
        obniz.display.clear();
        obniz.display.print("ばっくします!")
        moveTo(-1 * power, -1 * power);
      }
      else if (isKeywordsIncludes(json.responses, ["こっち","こちら", "here"])) {
        let pos = isKeywordsIncludes(json.responses, ["こっち", "こちら","here"]);
        let sum = 0;
        for (let p of pos.vertices) {
          sum += p.x;
        }
        let avg = sum / 4;
        let rotate = (avg - canvasOutput.width / 2) / canvasOutput.width;
        moveTo(rotate * power, (1 - rotate) * power);
      } else {
        _log("keyward nothing");
        moveTo(0, 0);
      }
      inOperation = false;
    });

  }

  function isKeywordsIncludes(results, keywards) {
    if (!Array.isArray(keywards)) {
      keywards = [keywards];
    }
    for (let result of results) {
      if (result && result.labelAnnotations) {
        for (let anotation of result.labelAnnotations) {
          for (let keyward of keywards) {
            if (anotation.description.toLowerCase().indexOf(keyward) >= 0) {
              return anotation.boundingPoly || true;
            }
          }
        }
      }
      if (result && result.textAnnotations) {
        for (let anotation of result.textAnnotations) {
          for (let keyward of keywards) {
            if (anotation.description.toLowerCase().indexOf(keyward) >= 0) {
              return anotation.boundingPoly || true;
            }
          }
        }
      }
      if (result && result.fullTextAnnotation) {
        for (let keyward of keywards) {
          if (result.fullTextAnnotation.text.toLowerCase().indexOf(keyward) >= 0) {
            return result.fullTextAnnotation.boundingPoly || true;
          }
        }
      }
      return false;
    }
  }

  function _log(msg) {
    let log = document.getElementById("log");
    log.innerHTML += msg + "<br/>";
    log.scrollTop = log.scrollHeight;
  }



</script>
</body>
</html>




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