Dynamsoft Barcode Reader JavaScript Edition (DBR-JS) is equipped with industry-leading algorithms for exceptional speed, accuracy and read rates in barcode reading. Using its well-designed API, you can turn your web page into a barcode scanner with just a few lines of code.
Once the DBR-JS SDK gets integrated into your web page, your users can access a camera via the browser and read barcodes directly from its video input.
In this guide, you will learn step by step on how to integrate the DBR-JS SDK into your website.
Table of Contents
- Barcode Reader for Your Website - User Guide
- Hello World - Simplest Implementation
- Building your own page
- API Documentation
- System Requirements
- How to Upgrade
- Release Notes
- Next Steps
Popular Examples
- Hello World - Github | Run
- Angular App - Github | Run
- React App - Github | Run
- Vue App - Github | Run
- PWA App - Github | Run
- WebView in Android and iOS - Github
- Read Driver Licenses - Github | Run
- Fill A Form - Github | Run
- Show result information on the video - Github | Run
- Debug Camera and Collect Video Frame - Github
You can also:
Let's start with the "Hello World" example of the DBR-JS SDK which demonstrates how to use the minimum code to enable a web page to read barcodes from a live video stream.
Basic Requirements
- Internet connection
- A supported browser
- Camera access
The complete code of the "Hello World" example is shown below
<!DOCTYPE html>
<html>
<body>
<div id="cameraViewContainer" style="width: 100%; height: 60vh"></div>
<textarea id="results" style="width: 100%; min-height: 10vh; font-size: 3vmin; overflow: auto" disabled></textarea>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/dbr.bundle.js"></script>
<script>
Dynamsoft.License.LicenseManager.initLicense("DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9");
Dynamsoft.Core.CoreModule.loadWasm(["dbr"]);
(async () => {
let cvRouter = await Dynamsoft.CVR.CaptureVisionRouter.createInstance();
let view = await Dynamsoft.DCE.CameraView.createInstance();
let cameraEnhancer = await Dynamsoft.DCE.CameraEnhancer.createInstance(view);
document.querySelector("#cameraViewContainer").append(view.getUIElement());
cvRouter.setInput(cameraEnhancer);
const resultsContainer = document.querySelector("#results");
cvRouter.addResultReceiver({ onDecodedBarcodesReceived: (result) => {
if (result.barcodeResultItems.length > 0) {
resultsContainer.textContent = '';
for (let item of result.barcodeResultItems) {
resultsContainer.textContent += `${item.formatString}: ${item.text}\n\n`;
}
}
}});
let filter = new Dynamsoft.Utility.MultiFrameResultCrossFilter();
filter.enableResultCrossVerification("barcode", true);
filter.enableResultDeduplication("barcode", true);
await cvRouter.addResultFilter(filter);
await cameraEnhancer.open();
await cvRouter.startCapturing("ReadSingleBarcode");
})();
</script>
</body>
</html>
-
Dynamsoft.License.LicenseManager.initLicense(): This method initializes the license for using the SDK in the application. Note that the string "DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9" used in this example points to an online license that requires a network connection to work. Read more on Specify the license. -
Dynamsoft.Core.CoreModule.loadWasm(["dbr"]): This is an optional code. Used to load wasm resources in advance, reducing latency between video playing and barcode decoding. -
Dynamsoft.CVR.CaptureVisionRouter.createInstance(): This method creates aCaptureVisionRouterobjectcvRouterwhich controls the entire process in three steps:- Retrieve Images from the Image Source
cvRouterconnects to the image source through the ImageSourceAdapter interface with the methodsetInput().cvRouter.setInput(cameraEnhancer);
The image source in our case is a CameraEnhancer object created with
Dynamsoft.DCE.CameraEnhancer.createInstance(view) - Coordinate Image-Processing Tasks
- The coordination happens behind the scenes.
cvRouterstarts the process by specifying a preset template "ReadSingleBarcode" in the methodstartCapturing().cvRouter.startCapturing("ReadSingleBarcode");
- The coordination happens behind the scenes.
- Dispatch Results to Listening Objects
- The processing results are returned through the CapturedResultReceiver interface. The
CapturedResultReceiverobject is registered tocvRoutervia the methodaddResultReceiver(). For more information, please check out Register a result receiver.cvRouter.addResultReceiver({/*The-CapturedResultReceiver-Object"*/});
- Also note that reading from video is extremely fast and there could be many duplicate results. We can use a filter with result deduplication enabled to filter out the duplicate results. The object is registered to
cvRoutervia the methodaddResultFilter().cvRouter.addResultFilter(filter);
- The processing results are returned through the CapturedResultReceiver interface. The
- Retrieve Images from the Image Source
Read more on Capture Vision Router.
You can run the example deployed to the Dynamsoft Demo Server or test it with JSFiddle code editor.
You will be asked to allow access to your camera, after which the video will be displayed on the page. After that, you can point the camera at a barcode to read it.
When a barcode is decoded, you will see the result text show up under the video and the barcode location will be highlighted in the video feed.
Alternatively, you can test locally by copying and pasting the code shown above into a local file (e.g. "hello-world.html") and opening it in your browser.
Note:
If you open the web page as file:/// or http:// , the camera may not work correctly because the MediaDevices: getUserMedia() method only works in secure contexts (HTTPS), in some or all supporting browsers.
To make sure your web application can access the camera, please configure your web server to support HTTPS. The following links may help.
- NGINX: Configuring HTTPS servers
- IIS: How to create a Self Signed Certificate in IIS
- Tomcat: Setting Up SSL on Tomcat in 5 minutes
- Node.js: npm tls
If the test doesn't go as expected, you can contact us.
To utilize the SDK, the initial step involves including the corresponding resource files:
core.jsencompasses common classes, interfaces, and enumerations shared across all Dynamsoft SDKs.license.jsintroduces theLicenseManagerclass, which manages the licensing for all Dynamsoft SDKs.utility.jsencompasses auxiliary classes shared among all Dynamsoft SDKs.dbr.jsdefines interfaces and enumerations tailored to the barcode reader module.cvr.jsintroduces theCaptureVisionRouterclass, which governs the entire image processing workflow.dce.jscomprises classes that offer camera support and basic user interface functionalities.
To simplify things, starting from version 10.0.21, we introduced dbr.bundle.js, which combines all six of the above files. In the following chapters, we will use dbr.bundle.js.
The simplest way to include the SDK is to use either the jsDelivr or UNPKG CDN. The "hello world" example above uses jsDelivr.
-
jsDelivr
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/dbr.bundle.js"></script>
-
UNPKG
<script src="https://unpkg.com/[email protected]/dist/dbr.bundle.js"></script>
-
In some rare cases (such as some restricted areas), you might not be able to access the CDN. If this happens, you can use the following files for the test.
<script src="https://download2.dynamsoft.com/packages/[email protected]/dist/dbr.bundle.js"></script>
However, please DO NOT use
download2.dynamsoft.comresources in a production application as they are for temporary testing purposes only. Instead, you can try hosting the SDK yourself. -
In frameworks like React and Vue, you may want to add the package as a dependency.
npm i [email protected] -E # or yarn add [email protected] -E
In frameworks you need to specify the engineResourcePaths.
Besides using the public CDN, you can also download the SDK and host its files on your own server or a commercial CDN before including it in your application.
Options to download the SDK:
-
From the website
Download Dynamsoft Barcode Reader JavaScript Package
The resources are located at path
dynamsoft/distributables/<pkg>@<version>. -
npm
npm i [email protected] -E # Compared with using CDN, you need to set up more resources. npm i [email protected] -E npm i [email protected] -E
The resources are located at path
node_modules/<pkg>, without@<version>.
Depending on how you downloaded the SDK and how you intend to use it, you can typically include it like this
-
From the website
<script src="dynamsoft/distributables/[email protected]/dist/dbr.bundle.js"></script>
-
From node_modules
<script src="node_modules/dynamsoft-barcode-reader-bundle/dist/dbr.bundle.js"></script>
Since
@<version>are missing, you need to specify the engineResourcePaths.
Note:
-
Certain legacy web application servers may lack support for the
application/wasmmimetype for .wasm files. To address this, you have two options: -
To work properly, the SDK requires a few engine files, which are relatively large and may take quite a few seconds to download. We recommend that you set a longer cache time for these engine files, to maximize the performance of your web application.
Cache-Control: max-age=31536000Reference: Cache-Control.
Before using the SDK, you need to configure a few things.
To enable the SDK's functionality, you must provide a valid license. Utilize the API function initLicense to set your license key.
Dynamsoft.License.LicenseManager.initLicense("DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9");As previously stated, the key "DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9" serves as a test license valid for 24 hours, applicable to any newly authorized browser. To test the SDK further, you can request a 30-day free trial license via the customer portal.
Upon registering a Dynamsoft account and obtaining the SDK package from the official website, Dynamsoft will automatically create a 30-day free trial license and embed the corresponding license key into all the provided SDK samples.
This is usually only required with frameworks like Angular or React, etc. where the referenced JavaScript files such as cvr.js, dbr.js are compiled into another file.
The purpose is to tell the SDK where to find the engine files (*.worker.js, *.wasm.js and *.wasm, etc.). The API is called Dynamsoft.Core.CoreModule.engineResourcePaths:
//The following code uses the jsDelivr CDN, feel free to change it to your own location of these files
Object.assign(Dynamsoft.Core.CoreModule.engineResourcePaths, {
std: "https://cdn.jsdelivr.net/npm/[email protected]/dist/",
dip: "https://cdn.jsdelivr.net/npm/[email protected]/dist/",
core: "https://cdn.jsdelivr.net/npm/[email protected]/dist/",
license: "https://cdn.jsdelivr.net/npm/[email protected]/dist/",
cvr: "https://cdn.jsdelivr.net/npm/[email protected]/dist/",
dbr: "https://cdn.jsdelivr.net/npm/[email protected]/dist/",
dce: "https://cdn.jsdelivr.net/npm/[email protected]/dist/"
});The image processing logic is encapsulated within .wasm library files, and these files may require some time for downloading. To enhance the speed, we advise utilizing the following method to preload the libraries.
// Preload the .wasm files
await Dynamsoft.Core.CoreModule.loadWasm(["dbr"]);To use the SDK, we first create a CaptureVisionRouter object.
Dynamsoft.License.LicenseManager.initLicense("DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9");
let cvRouter = null;
try {
cvRouter = await Dynamsoft.CVR.CaptureVisionRouter.createInstance();
} catch (ex) {
console.error(ex);
}Tip:
When creating a CaptureVisionRouter object within a function which may be called more than once, it's best to use a "helper" variable to avoid double creation such as pCvRouter in the following code:
Dynamsoft.License.LicenseManager.initLicense("DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9");
let pCvRouter = null; // promise of cvRouter
let cvRouter = null;
document.getElementById('btn-scan').addEventListener('click', async () => {
try {
cvRouter = await (pCvRouter = pCvRouter || Dynamsoft.CVR.CaptureVisionRouter.createInstance());
} catch (ex) {
console.error(ex);
}
});The CaptureVisionRouter object, denoted as cvRouter, is responsible for handling images provided by an image source. In our scenario, we aim to detect barcodes directly from a live video stream. To facilitate this, we initialize a CameraEnhancer object, identified as cameraEnhancer, which is specifically designed to capture image frames from the video feed and subsequently forward them to cvRouter.
To enable video streaming on the webpage, we create a CameraView object referred to as view, which is then passed to cameraEnhancer, and its content is displayed on the webpage.
<div id="cameraViewContainer" style="width: 100%; height: 100vh"></div>let view = await Dynamsoft.DCE.CameraView.createInstance();
let cameraEnhancer = await Dynamsoft.DCE.CameraEnhancer.createInstance(view);
document.querySelector("#cameraViewContainer").append(view.getUIElement());
cvRouter.setInput(cameraEnhancer);Once the image processing is complete, the results are sent to all the registered CapturedResultReceiver objects. Each CapturedResultReceiver object may encompass one or multiple callback functions associated with various result types. In our particular case, our focus is on identifying barcodes within the images, so it's sufficient to define the callback function onDecodedBarcodesReceived:
const resultsContainer = document.querySelector("#results");
const resultReceiver = new Dynamsoft.CVR.CapturedResultReceiver();
resultReceiver.onDecodedBarcodesReceived = (result) => {
if (result.barcodeResultItems.length > 0) {
resultsContainer.textContent = '';
for (let item of result.barcodeResultItems) {
// In this example, the barcode results are displayed on the page below the video.
resultsContainer.textContent += `${item.formatString}: ${item.text}\n\n`;
}
}
};
cvRouter.addResultReceiver(resultReceiver);You can also write code like this. It is the same.
const resultsContainer = document.querySelector("#results");
cvRouter.addResultReceiver({ onDecodedBarcodesReceived: (result) => {
if (result.barcodeResultItems.length > 0) {
resultsContainer.textContent = '';
for (let item of result.barcodeResultItems) {
// In this example, the barcode results are displayed on the page below the video.
resultsContainer.textContent += `${item.formatString}: ${item.text}\n\n`;
}
}
}});Check out CapturedResultReceiver for more information.
With the setup now complete, we can proceed to process the images in two straightforward steps:
- Initiate the image source to commence image acquisition. In our scenario, we invoke the
open()method oncameraEnhancerto initiate video streaming and simultaneously initiate the collection of images. These collected images will be dispatched tocvRouteras per its request. - Define a preset template to commence image processing. In our case, we utilize the "ReadSingleBarcode" template, specifically tailored for processing images containing a single barcode.
await cameraEnhancer.open();
await cvRouter.startCapturing("ReadSingleBarcode");Note:
cvRouteris engineered to consistently request images from the image source.- Various preset templates are at your disposal for barcode reading:
| Template Name | Function Description |
|---|---|
| ReadBarcodes_Default | Scans a single barcode. |
| ReadSingleBarcode | Quickly scans a single barcode. |
| ReadBarcodes_SpeedFirst | Prioritizes speed in scanning multiple barcodes. |
| ReadBarcodes_ReadRateFirst | Maximizes the number of barcodes read. |
| ReadBarcodes_Balance | Balances speed and quantity in reading multiple barcodes. |
| ReadDenseBarcodes | Specialized in reading barcodes with high information density. |
| ReadDistantBarcodes | Capable of reading barcodes from extended distances. |
Read more on the preset CaptureVisionTemplates.
When making adjustments to some basic tasks, we often only need to modify SimplifiedCaptureVisionSettings.
The preset templates can be updated to meet different requirements. For example, the following code limits the barcode format to QR code.
let settings = await cvRouter.getSimplifiedSettings("ReadSingleBarcode");
settings.barcodeSettings.barcodeFormatIds =
Dynamsoft.DBR.EnumBarcodeFormat.BF_QR_CODE;
await cvRouter.updateSettings("ReadSingleBarcode", settings);
await cvRouter.startCapturing("ReadSingleBarcode");For a list of adjustable barcode settings, check out SimplifiedBarcodeReaderSettings.
Additionally, we have the option to modify the template to retrieve the original image containing the barcode.
let settings = await cvRouter.getSimplifiedSettings("ReadSingleBarcode");
settings.capturedResultItemTypes |=
Dynamsoft.Core.EnumCapturedResultItemType.CRIT_ORIGINAL_IMAGE;
await cvRouter.updateSettings("ReadSingleBarcode", settings);
await cvRouter.startCapturing("ReadSingleBarcode");Limit the barcode format to QR code, and retrieve the original image containing the barcode, at the same time.
let settings = await cvRouter.getSimplifiedSettings("ReadSingleBarcode");
settings.capturedResultItemTypes =
Dynamsoft.DBR.EnumBarcodeFormat.BF_QR_CODE |
Dynamsoft.Core.EnumCapturedResultItemType.CRIT_ORIGINAL_IMAGE;
await cvRouter.updateSettings("ReadSingleBarcode", settings);
await cvRouter.startCapturing("ReadSingleBarcode");Please be aware that it is necessary to update the CapturedResultReceiver object to obtain the original image. For instance:
const EnumCRIT = Dynamsoft.Core.EnumCapturedResultItemType;
resultReceiver.onCapturedResultReceived = (result) => {
let barcodes = result.items.filter(item => item.type === EnumCRIT.CRIT_BARCODE);
if (barcodes.length > 0) {
let image = result.items.filter(
item => item.type === EnumCRIT.CRIT_ORIGINAL_IMAGE
)[0].imageData;
// The image that we found the barcode(s) on.
}
};The SDK is initially configured to process images sequentially without any breaks. Although this setup maximizes performance, it can lead to elevated power consumption, potentially causing the device to overheat. In many cases, it's possible to reduce the reading speed while still satisfying business requirements. The following code snippet illustrates how to adjust the SDK to process an image every 500 milliseconds:
Please bear in mind that in the following code, if an image's processing time is shorter than 500 milliseconds, the SDK will wait for the full 500 milliseconds before proceeding to process the next image. Conversely, if an image's processing time exceeds 500 milliseconds, the subsequent image will be processed immediately upon completion.
let settings = await cvRouter.getSimplifiedSettings("ReadSingleBarcode");
settings.minImageCaptureInterval = 500;
await cvRouter.updateSettings("ReadSingleBarcode", settings);
await cvRouter.startCapturing("ReadSingleBarcode");You can use the parameter roi (region of interest) together with the parameter roiMeasuredInPercentage to configure the SDK to only read a specific region on the image frames. For example, the following code limits the reading in the center 25%( = 50% * 50%) of the image frames:
let settings = await cvRouter.getSimplifiedSettings("ReadSingleBarcode");
settings.roiMeasuredInPercentage = true;
settings.roi.points = [
{ x: 25, y: 25 },
{ x: 75, y: 25 },
{ x: 75, y: 75 },
{ x: 25, y: 75 },
];
await cvRouter.updateSettings("ReadSingleBarcode", settings);
await cvRouter.startCapturing("ReadSingleBarcode");While the code above accomplishes the task, a more effective approach is to restrict the scan region directly at the image source, as demonstrated in the following code snippet.
- With the region configured at the image source, the images are cropped right before they are gathered for processing, eliminating the necessity to modify the processing settings further.
cameraEnhancerelevates interactivity by overlaying a mask on the video, providing a clear delineation of the scanning region.- See also: CameraEnhancer::setScanRegion
cameraEnhancer = await Dynamsoft.DCE.CameraEnhancer.createInstance(view);
cameraEnhancer.setScanRegion({
x: 25,
y: 25,
width: 50,
height: 50,
isMeasuredInPercentage: true,
});The preset templates have a lot more settings that can be customized to best suit your use case. If you download the SDK from Dynamsoft website, you can find the templates under
- "/dynamsoft-barcode-reader-js-10.2.10/dynamsoft/resources/barcode-reader/templates/"
Upon completing the template editing, you can invoke the initSettings method and provide it with the template path as an argument.
await cvRouter.initSettings("PATH-TO-THE-FILE"); //e.g. "https://your-website/ReadSingleBarcode.json")
await cvRouter.startCapturing("ReadSingleBarcode"); // Make sure the name matches one of the CaptureVisionTemplates in the json file.While processing video frames, it's common for the same barcode to be detected multiple times. To enhance the user experience, we can use MultiFrameResultCrossFilter object, having two options currently at our disposal:
let filter = new Dynamsoft.Utility.MultiFrameResultCrossFilter();
filter.enableResultCrossVerification("barcode", true);
await cvRouter.addResultFilter(filter);Note:
enableResultCrossVerificationwas designed to cross-validate the outcomes across various frames in a video streaming scenario, enhancing the reliability of the final results. This validation is particularly crucial for barcodes with limited error correction capabilities, such as 1D codes.
let filter = new Dynamsoft.Utility.MultiFrameResultCrossFilter();
filter.enableResultDeduplication("barcode", true);
await cvRouter.addResultFilter(filter);Note:
enableResultDeduplicationwas designed to prevent high usage in video streaming scenarios, addressing the repetitive processing of the same code within a short period of time.
Initially, the filter is set to forget a result 3 seconds after it is first received. During this time frame, if an identical result appears, it is ignored.
It's important to know that in version 9.x or earlier, the occurrence of an identical result would reset the timer, thus reinitiating the 3-second count at that point. However, in version 10.2.10 and later, an identical result no longer resets the timer but is instead disregarded, and the duration count continues uninterrupted.
Under certain circumstances, this duration can be extended with the method setDuplicateForgetTime().
let filter = new Dynamsoft.Utility.MultiFrameResultCrossFilter();
filter.setDuplicateForgetTime(5000); // Extend the duration to 5 seconds.
await cvRouter.addResultFilter(filter);You can also enable both options at the same time:
let filter = new Dynamsoft.Utility.MultiFrameResultCrossFilter();
filter.enableResultCrossVerification("barcode", true);
filter.enableResultDeduplication("barcode", true);
filter.setDuplicateForgetTime(5000);
await cvRouter.addResultFilter(filter);When a barcode is detected within the video stream, its position is immediately displayed within the video. Furthermore, utilizing the "Dynamsoft Camera Enhancer" SDK, we can introduce feedback mechanisms, such as emitting a "beep" sound or triggering a "vibration".
The following code snippet adds a "beep" sound for when a barcode is found:
const resultReceiver = new Dynamsoft.CVR.CapturedResultReceiver();
resultReceiver.onDecodedBarcodesReceived = (result) => {
if (result.barcodeResultItems.length > 0) {
Dynamsoft.DCE.Feedback.beep();
}
};
cvRouter.addResultReceiver(resultReceiver);The UI is part of the auxiliary SDK "Dynamsoft Camera Enhancer", read more on how to customize the UI.
You can check out the detailed documentation about the APIs of the SDK at https://www.dynamsoft.com/barcode-reader/docs/web/programming/javascript/api-reference/?ver=10.2.10.
DBR requires the following features to work:
-
Secure context (HTTPS deployment)
When deploying your application / website for production, make sure to serve it via a secure HTTPS connection. This is required for two reasons
- Access to the camera video stream is only granted in a security context. Most browsers impose this restriction.
Some browsers like Chrome may grant the access for
http://127.0.0.1andhttp://localhostor even for pages opened directly from the local disk (file:///...). This can be helpful for temporary development and test.- Dynamsoft License requires a secure context to work.
-
WebAssembly,Blob,URL/createObjectURL,Web WorkersThe above four features are required for the SDK to work.
-
MediaDevices/getUserMediaThis API is required for in-browser video streaming.
-
getSettingsThis API inspects the video input which is a
MediaStreamTrackobject about its constrainable properties.
The following table is a list of supported browsers based on the above requirements:
| Browser Name | Version |
|---|---|
| Chrome | v78+1 |
| Firefox | v62+1 |
| Edge | v79+ |
| Safari | v14+ |
1 devices running iOS needs to be on iOS 14.3+ for camera video streaming to work in Chrome, Firefox or other Apps using webviews.
Apart from the browsers, the operating systems may impose some limitations of their own that could restrict the use of the SDK. Browser compatibility ultimately depends on whether the browser on that particular operating system supports the features listed above.
If you want to upgrade the SDK from an old version to a newer one, please see how to upgrade.
Learn about what are included in each release at https://www.dynamsoft.com/barcode-reader/docs/web/programming/javascript/release-notes/index.html.
Now that you have got the SDK integrated, you can choose to move forward in the following directions
- Check out the Official Samples and Demo
- Learn about the APIs of the SDK
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