barcode-reader-javascript-samples/foundational-api-samples/use-case/show-result-texts-on-the-video.html at 826defc3c19995638249348dcd164b24db89db4d · Dynamsoft/barcode-reader-javascript-samples · GitHub

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<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <meta name="description" content="Read barcodes from camera with Dynamsoft Barcode Reader and display result texts as overlays on video." />
  <meta name="keywords" content="read barcode from camera, overlay" />
  <link rel="canonical" href="https://demo.dynamsoft.com/Samples/DBR/JS/use-case/show-result-texts-on-the-video.html" />
  <title>Dynamsoft Barcode Reader Sample - Display Barcode Results as Video Overlays</title>
  <style>
    .bubble-box-container {
      position: absolute;
      display: flex;
      justify-content: center;
    }

    .bubble-box-container>.bubble-box {
      position: absolute;
      width: max-content;
      max-width: 20rem;
      background: white;
      border-radius: 4px;
      padding: 4px;
      word-break: break-all;
      word-wrap: break-word;
      box-shadow: 5px 5px 5px 3px rgba(0, 0, 0, 0.2);
      transform: translateY(calc(-100% - 4px));
    }

    .bubble-box-container>.bubble-box::after {
      content: "";
      position: absolute;
      bottom: -8px;
      left: calc(50% - 8px);
      border-left: 8px solid transparent;
      border-top: 8px solid white;
      border-right: 8px solid transparent;
    }
  </style>
</head>

<body>
  <h1>Display Barcode Results as Video Overlays</h1>
  <h3>Scan barcodes to display results as overlays on video</h3>
  <div id="camera-view-container" style="width: 100%; height: 90vh"></div>
  <div id="results"></div>
  <script src="https://cdn.jsdelivr.net/npm/dynamsoft-barcode-reader-bundle@10.5.3000/dist/dbr.bundle.min.js"></script>
  <!-- If the network is unstable or you prefer to self-host the SDK, uncomment the line below to load it locally -->
  <!-- <script src="../../../distributables/dbr.bundle.js"></script> -->
  <script>
    /** LICENSE ALERT - README
     * To use the library, you need to first specify a license key using the API "initLicense()" as shown below.
     */

    Dynamsoft.License.LicenseManager.initLicense("DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9");

    /**
     * You can visit https://www.dynamsoft.com/customer/license/trialLicense?utm_source=samples&product=dbr&package=js to get your own trial license good for 30 days.
     * Note that if you downloaded this sample from Dynamsoft while logged in, the above license key may already be your own 30-day trial license.
     * For more information, see https://www.dynamsoft.com/barcode-reader/docs/web/programming/javascript/user-guide/index.html?ver=10.5.3000&cVer=true#specify-the-license&utm_source=samples or contact support@dynamsoft.com.
     * LICENSE ALERT - THE END
     */

    // Optional. Used to load wasm resources in advance, reducing latency between video playing and barcode decoding.
    Dynamsoft.Core.CoreModule.loadWasm(["DBR"]);
    // // If the network is unstable or you prefer to self-host the SDK, uncomment the line below to define the root path of the engine files
    // Dynamsoft.Core.CoreModule.engineResourcePaths.rootDirectory = "../../../distributables/";
    const resultsContainer = document.querySelector("#results");

    (async () => {
      try {
        // Create a `CameraEnhancer` instance for camera control and a `CameraView` instance for UI control.
        const cameraView = await Dynamsoft.DCE.CameraView.createInstance();
        const cameraEnhancer = await Dynamsoft.DCE.CameraEnhancer.createInstance(cameraView);
        // Get default UI and append it to DOM.
        document.querySelector("#camera-view-container").append(cameraView.getUIElement());

        // Create a `CaptureVisionRouter` instance and set `CameraEnhancer` instance as its image source.
        const cvRouter = await Dynamsoft.CVR.CaptureVisionRouter.createInstance();
        cvRouter.setInput(cameraEnhancer);

        // Define a callback for results.
        const bodyStyle = getComputedStyle(document.body);
        cvRouter.addResultReceiver({
          onCapturedResultReceived: (result) => {
            // Reset results
            resultsContainer.innerText = "";

            // Determine if body `position` is `static`, `relative`, `absolute`, etc.
            const isBodyStyleStatic = bodyStyle.position === "static";
            let bodyStaticTopOffset, bodyStaticLeftOffset;
            if (isBodyStyleStatic) {
              const bodyRect = document.body.getBoundingClientRect();
              bodyStaticTopOffset = bodyRect.top + parseFloat(bodyStyle.borderTopWidth);
              bodyStaticLeftOffset = bodyRect.left + parseFloat(bodyStyle.borderLeftWidth);
            }

            // loop through each barcode result
            for (let item of result.items) {
              if (item.type != Dynamsoft.Core.EnumCapturedResultItemType.CRIT_BARCODE) {
                continue; // Skip processing if the result is not a barcode
              }

              // Get the points of the quadrilateral surrounding the scanned barcode
              const p = item.location.points;
              // Calculate the top-left and bottom-right coordinates of the quadrilateral
              // This will help in positioning the result overlay on top of the scanned barcode
              const barcodeTopLeft = {
                x: Math.min(p[0].x, p[1].x, p[2].x, p[3].x),
                y: Math.min(p[0].y, p[1].y, p[2].y, p[3].y),
              };
              const barcodeBottomRight = {
                x: Math.max(p[0].x, p[1].x, p[2].x, p[3].x),
                y: Math.max(p[0].y, p[1].y, p[2].y, p[3].y),
              };

              // Create an `absolute` positioned container to overlay on top of the video
              const bubbleBoxContainer = document.createElement("div");
              bubbleBoxContainer.className = "bubble-box-container";

              // Create the overlay element to display decoded barcode results
              const bubbleBoxOverlay = document.createElement("div");
              bubbleBoxOverlay.className = "bubble-box";
              bubbleBoxOverlay.innerText = item.text;
              bubbleBoxContainer.append(bubbleBoxOverlay);

              // Position the overlay container relative to the document or viewport
              if (isBodyStyleStatic) {
                /**
                 * 'convertToPageCoordinates()' is used to converts coordinate of a barcode location to the coordinate relative to the document.
                 * Then we can place a div element according to the converted coordinate.
                 */
                const pageTopLeft = cameraEnhancer.convertToPageCoordinates(barcodeTopLeft);
                const pageBottomRight = cameraEnhancer.convertToPageCoordinates(barcodeBottomRight);
                const pageMidX = (pageTopLeft.x + pageBottomRight.x) / 2;
                bubbleBoxContainer.style.top = `${pageTopLeft.y}px`;
                bubbleBoxContainer.style.left = `${pageMidX}px`;
              } else {
                // if you set body `position` as `relative`, `absolute`, and so on,
                // we'll have to use set the position relative to the viewport.
                /**
                 * 'convertToClientCoordinates()' is used to converts coordinate of a barcode location to the coordinate relative to the viewport.
                 * Then we can place a div element according to the converted coordinate.
                 */
                const clientTopLeft = cameraEnhancer.convertToClientCoordinates(barcodeTopLeft);
                const clientBottomRight = cameraEnhancer.convertToClientCoordinates(barcodeBottomRight);
                const clientMidX = (clientTopLeft.x + clientBottomRight.x) / 2;
                bubbleBoxContainer.style.top = `${clientTopLeft.y - bodyStaticTopOffset}px`;
                bubbleBoxContainer.style.left = `${clientMidX - bodyStaticLeftOffset}px`;
              }
              resultsContainer.append(bubbleBoxContainer);

              /**
               * You can also add more information, such as displaying product images.
               */
            }
          },
        });

        // Filter out unchecked and duplicate results.
        const filter = new Dynamsoft.Utility.MultiFrameResultCrossFilter();
        // Filter out unchecked barcodes.
        filter.enableResultCrossVerification("barcode", true);

        // Open camera and start scanning single barcode.
        await cameraEnhancer.open();
        cameraView.setScanLaserVisible(true);
        await cvRouter.startCapturing("ReadBarcodes_SpeedFirst");
      } catch (ex) {
        let errMsg = ex.message || ex;
        console.error(errMsg);
        alert(errMsg);
      }
    })();
  </script>
</body>

</html>