DOT Web Face Auto Capture

v6.2.0

Introduction

DOT Web Face Auto Capture is set of Non-ui component and Ui component web components to capture image of user’s face.

Non-ui component is a web component that renders the video stream from an available phone or web camera to automatically capture an image of a user’s face with the required quality.

Ui component is a web component that renders an overlay over video stream. Overlay includes a placeholder, camera control buttons and instructions to guide the user to position their face correctly.

Supported Browsers

DOT Web Face Auto Capture was tested with:

  • Chrome on desktop (Windows, Mac and Linux) and mobile (Android, iPhone)

  • Firefox on desktop (Windows, Mac and Linux) and mobile (Android)****

  • Edge on Windows

  • Safari on Mac, iPad and iPhone

  • WebView on Android*

  • SafariVC on iPad and iPhone**

  • WKWebView on iPad and iPhone***

Known issues:

* Some older Android phones can experience issues with camera stream initialization using WebRTC. Our web components will work on most of them, but camera stream could be slow and laggy. This issue is caused by device and can be experienced in any website using WebRTC in Android WebView.

** Components are tested with SafariVC on devices iPhone 7 and newer with iOS 15 or iPadOS 15 or newer. Older devices or iOS versions are not officially supported and might experience issues.

*** In order to run DOT Web Face Auto Capture in WKWebView on iPhone or iPad, allowsInlineMediaPlayback and mediaTypesRequiringUserActionForPlayback properties on WKWebViewConfiguration must be set to true.

**** Some older and/or low-end Android phones can experience issues with camera stream initialization using WebRTC when using Firefox browser. Our web components might display The webcam is already in use by another application error. This issue is caused by the Firefox’s implementation of initialization of camera and can be experienced in any website using WebRTC in Firefox on Android. It is recommended to use other supported browsers in those cases.

Privacy and security

This component can only be used in secure contexts due to MediaDevices API used for handling camera access. A secure context is, in short, a page loaded using HTTPS or the file:/// URL scheme, or a page loaded from localhost. Before accessing any camera, the component must always get the user’s permission. Browsers may offer a once-per-domain permission feature, but they must ask at least the first time, and the user has to specifically grant ongoing permission if they choose to do so. Browsers are required to display an indicator that shows that a camera or microphone is in use. More details can be found on MDN docs.

Non-ui component

Requirements

Minimum required camera resolution for appropriate results is 720x720. Anything less is insufficient.

Initialization

DOT Web Face Auto Capture can be installed via NPM, yarn or pnpm

npm install @innovatrics/dot-face-auto-capture

To manually integrate the DOT Web Face Auto Capture, download latest version from the Github repository. Then add following line to dependencies in your package.json:

"dependencies": {
    "@innovatrics/dot-face-auto-capture": "file:innovatrics-dot-face-auto-capture-[VERSION].tgz"
},

where [VERSION] is the DOT Web Face Auto Capture version integrated. This installs dot-face-auto-capture as an external module that can then be used (just like any other module in the code). For example, one could do import '@innovatrics/dot-face-auto-capture'; in the app.

Usage

Face auto capture component is a web component which uses custom HTML <x-dot-face-auto-capture/> tag. Properties cameraOptions needs to be passed into component after <x-dot-face-auto-capture/> tag was rendered.

import type {
  FaceCameraProps,
  HTMLFaceCaptureElement,
  FaceCallback
} from "@innovatrics/dot-face-auto-capture";

import { useEffect } from "react";
import "@innovatrics/dot-face-auto-capture";

const FaceCamera = (props: FaceCameraProps) => {
  useEffect(() => {
    const faceAutoCaptureHTMLElement = document.getElementById(
      "x-dot-face-auto-capture"
    ) as HTMLFaceCaptureElement | null;

    if (faceAutoCaptureHTMLElement) {
      faceAutoCaptureHTMLElement.cameraOptions = props;
    }
  });

  return <x-dot-face-auto-capture id="x-dot-face-auto-capture" />;
};

const Page = () => {

  const handleFacePhotoTaken: FaceCallback = ({ image, data }, content) => {
    // ...
  };

  const handleError = (error: Error) => {
    alert(error);
  };

  return (
    <FaceCamera
      cameraFacing="user"
      onPhotoTaken={handleFacePhotoTaken}
      onError={handleError}
      sessionToken="1111-222-333-4444"
    />
  );
};

Alternatively, you can use useRef and useLayoutEffect to render a web component with its props.

import type {
  FaceCameraProps,
  HTMLFaceCaptureElement,
} from '@innovatrics/dot-face-auto-capture';

import { useLayoutEffect, useRef } from 'react';
import '@innovatrics/dot-face-auto-capture';

const FaceCamera = (props: FaceCameraProps) => {
  const ref = useRef<HTMLFaceCaptureElement | null>(null);

  useLayoutEffect(() => {
    const element = ref.current;

    if (element) {
      element.cameraOptions = props;
    }
  }, [props]);

  return <x-dot-face-auto-capture id="x-dot-face-auto-capture" ref={ref} />;
};

iOS - Requesting DeviceMotion Permissions

To utilize the device motion sensor and provide instructions for device_pitched instruction on iOS , it’s necessary to invoke the DeviceMotionEvent.requestPermission() method and acquire user consent. This requirement is set by Apple and isn’t specific to the DOT Web Face Auto Capture. The method returns a promise that yields a string – either "granted" or "denied". If the user has already granted permission, the promise will resolve instantly.

Unfortunately DeviceMotionEvent.requestPermission() could only be called on a "user gesture" event, such as a button click. Requesting permission without a user gesture event isn’t feasible. Given that, DOT Web Face Auto Capture doesn’t produce any suitable user gesture event, the method must be invoked from the parent component when a user gesture event takes place. For example, when user clicks a button "Continue to take selfie". Below is a TypeScript example illustrating the process:

type DeviceMotionEventWithPermissions = {
  requestPermission: () => Promise<PermissionState>;
} & DeviceMotionEvent;

try {
  const { requestPermission } = DeviceMotionEvent as unknown as DeviceMotionEventWithPermissions;

  if (typeof requestPermission === "function") {
    const response = await requestPermission();

    if (response === "granted") {
      // permissions granted
    } else {
      // permissions denied
    }
  }
} catch (error) {
  // handle error in standard way
}

Without this permission, the device_pitched instruction will not be available but the component will still work. Further information on this can be found in this article.

TypeScript

Declaration file is bundled inside package. To use with TypeScript, import types from @innovatrics/dot-face-auto-capture.

import type { FaceCallback, FaceCameraProps } from "@innovatrics/dot-face-auto-capture";

Hosting WASM files

During the initialization phase of the component, the component loads the required WASM binary files via HTTP fetch request. Please note that we do not provide any hosting for WASM files. That’s why it is essential that the customer provides the component with all WASM files from our distribution. To do so, please copy wasm directory from our distribution into your distribution every time you update to new version of the component. If you are using package manager, you can find wasm directory in node_modules/@innovatrics/dot-face-auto-capture/wasm.

@innovatrics/
|__ dot-face-auto-capture/
    |__ wasm/ <-- copy this directory
        |-- sam.wasm
        |-- sam_simd.wasm
        |-- dot_embedded_bg.wasm
        ...
    |-- package.json
    |-- README.md
    ...

By default, the component will try to fetch the desired wasm file from <PROJECT_ORIGIN>/wasm/<NAME_OF_DESIRED_FILE>.wasm. This can be changed using wasmDirectoryPath property. For example, if wasmDirectoryPath=/my-directory property is provided, the component will try to fetch the desired wasm file from <PROJECT_ORIGIN>/my-directory/<NAME_OF_DESIRED_FILE>.wasm. Please, do not provide absolute path to single wasm file, but only to the directory containing all wasm files. For more information, check out our samples on Github where you can find real examples of how to host wasm files in various technologies such as React, Angular, Vue, etc.

Troubleshooting

If you are having difficulties with hosting wasm files, check your browser console in dev tools. You should see an error message with more details about the problem. It’s also a good idea to look at the network tab in the developer tools and check that the wasm file has been loaded correctly. Please pay close attention to the actual response of the wasm load request, as an HTTP 200 status does not necessarily mean that the wasm file was loaded correctly. If you see application/wasm in response type, then wasm file was loaded correctly. If you see e.g. text/html in response type, then wasm file was not loaded correctly.

Licensing

In order to support wide adoption of the components, a free mode was developed in addition to the premium mode used by licensed customers.

Free mode

Components run in the free mode by default. This mode does not impose any feature limits, it just displays an watermark overlay over the component, to indicate not-licensed deployment. The overlay looks as on the image below:

freemium-overlay

Premium

To run components in premium mode, dot_embedded_bg.wasm and valid license files are needed. To initialize WASM binary file please follow a steps in Hosting WASM files. To use your license file you need to copy it to project public directory as <PROJECT_ORIGIN>/iengine.lic. By default, the component will try to fetch the desired license file from <PROJECT_ORIGIN>/iengine.lic or <PROJECT_ORIGIN>/license.lic*. This can be changed using licensePath property. For example if licensePath=/my-license.lic property is provided, the component will try to fetch the license file from <PROJECT_ORIGIN>/my-license.lic.

* Please note that fetching license from <PROJECT_ORIGIN>/license.lic by default is deprecated and will be removed in future versions. Please use <PROJECT_ORIGIN>/iengine.lic instead.

If one of the following steps fails, then component will run in [Freemium] mode:

  • WASM binary file not found

  • license file not found

  • license is not valid

In order to obtain the license, please contact your Innovatrics’ representative.

Properties

  • (Optional) ['user'] string cameraFacing – Defines which camera to acquire from the browser’s getUserMedia API

    • 'user' – The video source is facing toward the user; this is the selfie or front-facing camera on a smartphone

    • 'environment' – The video source is facing away from the user, thereby viewing their environment; this is the back camera on a smartphone

  • function onPhotoTaken – Callback on successful image capture

  • function onError – Callback in the case that an error occurred (see Handling errors)

    • (e: Error) ⇒ void

  • (Optional) string wasmDirectoryPath - Path to the location, where the directory with all wasm binary files are hosted

  • (Optional) string licensePath - Path to the license file

  • (Optional) string sessionToken – Unique identifier of the session

  • (Optional) object thresholds - Detection configuration

    • (Optional) [0.4] number faceConfidence - Detection confidence threshold

    • (Optional) [0.3] number sharpnessThreshold - Low sharpness threshold

    • (Optional) [0.2] number brightnessLowThreshold - Low brightness threshold

    • (Optional) [0.85] number brightnessHighThreshold - High brightness threshold

    • (optional) [0.05] number outOfBoundsThreshold - Face out of bounds threshold

    • (Optional) [0.16] number minFaceSizeRatio - Minimum face size ratio relative to shorter side of the camera resolution

    • (Optional) [0.2] number maxFaceSizeRatio - Maximum face size ratio relative to shorter side of the camera resolution

    • (Optional) [30] number devicePitchAngleThreshold - Maximum and minimum device pitch angle in degrees

  • (Optional) HTMLElement styleTarget - Provide an alternate DOM node to inject styles. DOM node has to exist inside DOM before auto-capture component is initialized. This is useful when rendering components in a shadow DOM. By default, the styles are injected into the <head> element of the document. See [style-target] example for more details.

  • (Optional) ['AUTO_CAPTURE'] captureMode - Defines a strategy for how a detection captures the desired image

    • 'AUTO_CAPTURE' - It is a standard way of how a detection captures an image. See Auto capture

    • 'WAIT_FOR_REQUEST' - Detection waits for request to capture an image. See Wait for request

Callback parameters

  • object data

    • Blob image – Returned image on successful capture in jpeg format

    • object data

      • object detection - Object contains all detection parameters and its values. Present if image was taken using auto capture (not manual capture).

      • object imageResolution - Width and height of the captured image.

  • Uint8Array content - output for DOT Digital Identity Service

Multi capture

Face auto capture component allows you to capture an unlimited number of faces without the need to reinitialize the webcam and detector. Component calls onPhotoTaken callback on every captured face photo. When onPhotoTaken is called, detection is paused. Camera stream and face detector stay initialized. Component is in waiting state. You should implement a custom UI for waiting state (e.g. overlay over our component). We provide a default UI, but it is not customizable.

Capture mode

Defines a strategy for how a detection captures the desired image.

Auto capture

It is an automated process that attempts to capture multiple valid images and selects the best one from them. If the component captures at least two valid images, it enters a phase called candidate selection. Once this phase is complete, the best image is selected and returned by the component using the onPhotoTaken callback.

Wait for request

It is a manual process that allows you to capture an image on request. In this mode, the component is ready and waiting for your command. More details about how to request an image can be found in Control Events. Once the component receives a request, it returns either the first image or the first valid image using the onPhotoTaken callback.

Please note that in this mode, the candidate selection phase used in Auto capture is ignored.

Implement dispatch 'continue-detection' event

import { dispatchControlEvent, FaceCustomEvent, ControlEventInstruction } from "@innovatrics/dot-face-auto-capture/events";

const continueDetection = () => {
  dispatchControlEvent(FaceCustomEvent.CONTROL, ControlEventInstruction.CONTINUE_DETECTION)
};

Without importing @innovatrics/dot-face-auto-capture/events.

function continueDetection() {
  document.dispatchEvent(
    new CustomEvent("face-auto-capture:control", {
      detail: { instruction: "continue-detection" },
    }),
  );
}

Handling errors

When an error occurs, we call onError callback with one parameter of type Error. We set name property to AutoCaptureError, and also message with more details. Component renders default UI for error state, but is not customizable, and integrator should implement own error handling. Component uses the MediaDevices API that provides access to connected media input devices like cameras and microphones. If the user denies permission to access or the webcam is not present, an error is thrown. We provide original error thrown by browser inside cause property of the error object. List of possible errors can be found on MDN docs.

Error example:

{
  name: "AutoCaptureError",
  message: "The webcam is already in use by another application",
  cause: DOMException: Could not start video source // Original error thrown by browser MediaDevices API
}

Ui component

Requirements

Both components must be wrapped in parent div with position: relative.

<div style={{position: "relative"}}>
  <FaceUi />
  <FaceCamera
    cameraFacing="user"
    onPhotoTaken={handlePhotoTaken}
    onError={onError}
  />
</div>

Initialization

UI component can be installed via NPM, yarn or pnpm

npm install @innovatrics/dot-auto-capture-ui

To manually integrate UI component, download latest version from the Github repository. Add following line to dependencies in your package.json:

"dependencies": {
    "@innovatrics/dot-auto-capture-ui": "file:innovatrics-dot-auto-capture-ui-[VERSION].tgz",
}

where [VERSION] is the DOT Web Face Auto Capture version integrated. This installs dot-auto-capture-ui as an external module that can be used (just like any other module in the code). For example, one could do import '@innovatrics/dot-auto-capture-ui'; in the app.

Usage

Face auto capture UI component is an web component which uses custom HTML <x-dot-face-auto-capture-ui /> tag. Properties props needs to be passed into component after <x-dot-face-auto-capture-ui /> tag was rendered.

import type { FaceUiProps, HTMLFaceUiElement } from "@innovatrics/dot-auto-capture-ui/face";

import { useEffect } from "react";
import "@innovatrics/dot-auto-capture-ui/face";

const FaceUi = (props: FaceUiProps) => {
  useEffect(() => {
    const uiElement = document.getElementById("x-dot-face-auto-capture-ui") as HTMLFaceUiElement | null;

    if (uiElement) {
      uiElement.props = props;
    }
  });

  return <x-dot-face-auto-capture-ui id="x-dot-face-auto-capture-ui" />;
};

Alternatively, you can use useRef and useLayoutEffect to render a web component with its props.

import type { FaceUiProps, HTMLFaceUiElement } from "@innovatrics/dot-auto-capture-ui/face";

import { useLayoutEffect, useRef } from "react";
import "@innovatrics/dot-auto-capture-ui/face";

const FaceUi = (props: FaceUiProps) => {
  const ref = useRef<HTMLFaceUiElement| null>(null);

  useLayoutEffect(() => {
    const element = ref.current;

    if (element) {
      element.props = props;
    }
  }, [props]);

  return <x-dot-face-auto-capture-ui id="x-dot-face-auto-capture-ui" ref={ref} />;
};

TypeScript

Declaration files are bundled inside package. Just import types from @innovatrics/dot-auto-capture-ui/face.

Properties

  • (Optional) string placeholder - One of the predefined placeholders in component that can be selected

    • 'circle-solid'

    • 'ellipse-solid' - Deprecated

    • 'man-solid' - Deprecated

    • 'woman-solid' - Deprecated

    • 'square-rounded-dash'

    • 'square-rounded-solid'

    • 'square-dash'

    • 'square-solid'

Placeholders 'man-solid', 'woman solid' and 'ellipse-solid' are deprecated. Please use one of our alternative placeholders instead.

  • (Optional) string backdropColor - To customize the color of the default face placeholder backdrop. E.g.:

    • 'rgba(10, 10, 10, 0.5)'

Please note that the backdrop can only be used with the default face placeholder. If you prefer not to use the backdrop, you can set the backdropColor to 'none'.

  • (Optional) object instructions - Modification of default messages for localization or customization

    • (Optional) ['Stay still…'] string candidate_selection - Shown when all validations are passed, i.e. the image is suitable for capture

    • (Optional) ['Move back'] string face_too_close - Shown when the face is too close to the camera

    • (Optional) ['Move closer'] string face_too_far - Shown when the face is too far from the camera

    • (Optional) ['Center your face'] string face_centering - Shown when the face is not centered in the placeholder

    • (Optional) ['Position your face into the circle'] string face_not_present - Shown when no face is detected

    • (Optional) ['Position your face into the circle'] string left_eye_not_present - Shown when left eye is not detected

    • (Optional) ['Position your face into the circle'] string right_eye_not_present - Shown when right eye is not detected

    • (Optional) ['Position your face into the circle'] string mouth_not_present - Shown when mouth is not detected

    • (Optional) ['Turn face against light'] string sharpness_too_low - Shown when the face in the image is not sharp enough

    • (Optional) ['Turn face against light'] string brightness_too_low - Shown when the image is too dark

    • (Optional) ['Less light needed'] string brightness_too_high - Shown when the image is too bright.

    • (Optional) ['Hold your phone at eye level'] string device_pitched - Shown when the device is pitched too much.

  • (Optional) theme - Modification of theme properties.

    • (Optional) colors - To customize colors of following properties

      • (Optional) ['white'] color placeholderColor - Color of the placeholder lines

      • (Optional) ['#00BFB2'] color placeholderColorSuccess - Color of the placeholder lines when all validations are passed

      • (Optional) ['white'] color instructionColor - Instruction background color

      • (Optional) ['#00BFB2'] color instructionColorSuccess - Instruction background color when all validations are passed

      • (Optional) ['black'] color instructionTextColor - Instruction text color

    • (Optional) font - To customize font with following properties

      • (Optional) ['Montserrat'] string family - Font family. Please note that the chosen font must be installed and available in the styles of the web components for it to display correctly.

      • (Optional) [14] number minimumSize - Minimum font size, from which the actual font size is calculated relative to the component width/height

      • (Optional) ['normal'] string style - Font style

      • (Optional) [600] string|number weight - Font weight

  • (Optional) appStateInstructions - Modification of default messages for component state

    • (Optional) loading - Component loading state

      • (Optional) ['Loading. Please wait.'] string text - Text shown while component is loading

      • (Optional) [true] boolean visible - Show/hide loading instruction while component is loading

    • (Optional) waiting - Component waiting state

      • (Optional) ['Waiting for input'] string text - Text shown while component is waiting

      • (Optional) [true] boolean visible - Show/hide waiting instruction while component is waiting

  • (Optional) [false] boolean showDetectionLayer - Show/hide detection layer on top of component

  • (Optional) [false] boolean showCameraButtons - Show/hide camera buttons (switch camera and toggle mirror) on top of component

  • (Optional) HTMLElement styleTarget - Provide an alternate DOM node to inject styles. DOM node has to exist inside DOM before auto-capture component is initialized. This is useful when rendering components in a shadow DOM. By default, the styles are injected into the <head> element of the document. See [style-target] example for more details.

Example how to use UI properties:

<FaceUi
  theme={{ colors: { placeholderColor: "green" }, font: { style: 'italic' } }}
  placeholder="ellipse-solid"
  instructions={{ candidate_selection: "Candidate selection" }}
  appStateInstructions={{ loading: { text: "Component is loading", visible: true } }}
  showDetectionLayer
  showCameraButtons
/>

Example how to use backdropColor prop for the default face placeholder backdrop:

<FaceUi
  theme={{ colors: { placeholderColor: "green" }, font: { style: 'italic' } }}
  backdropColor="rgba(10, 10, 10, 0.5)"
  instructions={{ candidate_selection: "Candidate selection" }}
  appStateInstructions={{ loading: { text: "Component is loading", visible: true } }}
  showDetectionLayer
  showCameraButtons
/>

Example how to import fonts (using head in main html file):

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <link rel="icon" type="" href="" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Title</title>
    <!-- import font in the head -->
    <link rel="preconnect" href="https://fonts.googleapis.com">
    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
    <link href="https://fonts.googleapis.com/css2?family=Montserrat&display=swap" rel="stylesheet">
    <!------->
  </head>
</html>

Example how to use styleTarget prop with Ui component when using Shadow DOM: This approach also works for Non-ui component.

import type { FaceUiProps, FaceUiElement } from "@innovatrics/dot-auto-capture-ui/face";
import "@innovatrics/dot-auto-capture-ui/face";
import { useEffect } from "react";

const FacetUi = (props: FaceUiProps) => {
  useEffect(() => {
    const uiElement = document.getElementById(
      "x-dot-face-auto-capture-ui"
    ) as HTMLFaceUiElement | null;

    const styleNode = document.createElement('div');

    uiElement?.shadowRoot?.append(styleNode);

    if (uiElement) {
       uiElement.props = {
        ...props,
        styleTarget: styleNode,
      };
    }
  });

  return <x-dot-face-auto-capture-ui id="x-dot-face-auto-capture-ui" />;
};

HTML of example above will look like this:

<x-dot-face-auto-capture-ui id="x-dot-face-auto-capture-ui">
  #shadow-root (open)
    <div>
      <style data-styled="active" data-styled-version="6.1.0">
        /* CSS styles will be injected here*/
      </style>
    </div>
</x-dot-face-auto-capture-ui>

Custom Events - Optional

Communication between components is based on custom events. Ui component is mostly listening to events dispatched by non-ui component. In case of CONTROL event, ui component dispatches control events to control non-ui component.

When using default [face-auto-capture-ui] component, only dispatch continue-detection event has to be implemented to use Multi capture.

Type of Events

Currently all events being used are described in this section. These are sufficient to build custom UI layer.

  • enum FaceCustomEvent - Event names dispatched by components

    • CONTROL = 'face-auto-capture:control - Events dispatched from 'ui' component to control non-ui component. Described in Control Events section

  • CAMERA_PROPS_CHANGED = 'face-auto-capture:camera-props-changed' - Notifies UI when camera properties has changed

    • INSTRUCTION_CHANGED = 'face-auto-capture:instruction-changed' - Notifies UI when instruction has changed

    • STATE_CHANGED = 'face-auto-capture:state-changed' - Notifies UI when state of non-ui component has changed

    • DETECTED_FACE_CHANGED = 'face-auto-capture:detected-face-changed' - Notifies UI when face is detected. Used in Detection Layer, has no effect if showDetectionLayer = false

    • VIDEO_ELEMENT_SIZE = 'face-auto-capture:video-element-size' - Notifies UI when HTML video element size has changed

  • enum ComponentCustomEvent - Event names dispatched by components

    • REQUEST_CAPTURE - dot-custom-event:request-capture - Event dispatched from outside of Non-ui component to request capture when component is running in WAIT_FOR_REQUEST capture mode. Described in Control Events section

Usage

Import @innovatrics/dot-face-auto-capture/events to use event types and and dispatch control events.

Listening to the Events

All event listeners are already implemented in default [face-auto-capture-ui] component. Skip this section if you are using default ui component.

All FaceCustomEvent events, except CONTROL, are dispatched by Face Auto Capture non-ui component. Ui component listens to these events to make appropriate changes. See the example below how to register event listeners.

import type {
  CameraPropsChangeEvent,
  CameraStateChangeEvent,
  VideoElementSizeChangeEvent,
  FaceInstructionChangeEvent
  DetectedFaceChangeEvent
} from "@innovatrics/dot-face-auto-capture/events";
import { FaceCustomEvent } from "@innovatrics/dot-face-auto-capture/events";
import type {
  AppState,
  FaceInstructionCode,
  Resolution,
  AutoCaptureError
} from "@innovatrics/dot-face-auto-capture";
import { useEffect, useState } from "react";


export const Events = () => {
  const [instructionCode, setInstructionCode] = useState<FaceInstructionCode | undefined>();
  const [cameraResolution, setCameraResolution] = useState<Resolution | undefined>();
  const [isMirroring, setIsMirroring] = useState<boolean | undefined>();
  const [appState, setAppState] = useState<AppState | undefined>();
  const [error, setError] = useState<AutoCaptureError | undefined>();
  const [videoElementSize, setVideoElementSize] = useState<DOMRect | undefined>();
  const [detectedFaceCorners, setDetectedFaceCorners] = useState<DetectedFaceCorners | undefined>();


  useEffect(() => {
    const handleInstruction = (event: FaceInstructionChangeEvent) => {
      setInstructionCode(event?.detail?.instructionCode);
    };

    const handleCameraProps = (event: CameraPropsChangeEvent) => {
      setCameraResolution(event?.detail?.cameraResolution);
      setIsMirroring(event?.detail?.isMirroring);
    };

    const handleAppState = (event: CameraStateChangeEvent) => {
      setAppState(event?.detail?.appState);

      const error = event?.detail?.error;

      if (error) {
        setError(error);
      }
    };

    const handleVideoElementSize = (event: VideoElementSizeChangeEvent) => {
      setVideoElementSize(event.detail?.size)
    }

    const handleDetectedFace = (event: DetectedFaceChangeEvent) => {
      setDetectedFaceCorners(event?.detail?.detectedCorners)
    }

    document.addEventListener(FaceCustomEvent.INSTRUCTION_CHANGED, handleInstruction);
    document.addEventListener(FaceCustomEvent.CAMERA_PROPS_CHANGED, handleCameraProps);
    document.addEventListener(FaceCustomEvent.STATE_CHANGED, handleAppState);
    document.addEventListener(FaceCustomEvent.VIDEO_ELEMENT_SIZE, handleVideoElementSize)
    document.addEventListener(FaceCustomEvent.DETECTED_FACE_CHANGED, handleDetectedFace)

    return () => {
      document.removeEventListener(FaceCustomEvent.INSTRUCTION_CHANGED, handleInstruction);
      document.removeEventListener(FaceCustomEvent.CAMERA_PROPS_CHANGED, handleCameraProps);
      document.removeEventListener(FaceCustomEvent.STATE_CHANGED, handleAppState);
      document.removeEventListener(FaceCustomEvent.VIDEO_ELEMENT_SIZE, handleVideoElementSize);
      document.removeEventListener(FaceCustomEvent.DETECTED_FACE_CHANGED, handleDetectedFace)
    };
  }, [])
}

Without importing @innovatrics/dot-face-auto-capture/events you can use values of FaceCustomEvent directly.

const instructionChangeEvent = "face-auto-capture:instruction-changed";

function handleInstructionChange(event) {
  console.log(event.detail.instructionCode)
}

document.addEventListener(instructionChangeEvent, handleInstructionChange);

/**
 * remove event listener when you're done
 */
document.removeEventListener(instructionChangeEvent, handleInstructionChange);

Control Events

Control events are dispatched from outside of Non-ui component to control it.

FaceCustomEvent.CONTROL

Events are dispatched from Ui component to control Non-ui component.

  • enum ControlEventInstruction

    • CONTINUE_DETECTION = 'continue-detection' - Controls Multi capture

    • SWITCH_CAMERA = 'switch-camera' - Notifies Face Auto Capture to use different camera

    • TOGGLE_MIRROR = 'toggle-mirror' - Notifies Face Auto Capture to mirror video stream

import { dispatchControlEvent, FaceCustomEvent, ControlEventInstruction } from "@innovatrics/dot-face-auto-capture/events";

export const Dispatch = () => {

  const continueDetection = () => {
    dispatchControlEvent(FaceCustomEvent.CONTROL, ControlEventInstruction.CONTINUE_DETECTION)
  }

  const switchCamera = () => {
    dispatchControlEvent(FaceCustomEvent.CONTROL, ControlEventInstruction.SWITCH_CAMERA)
  }

  const toggleMirror = () => {
    dispatchControlEvent(FaceCustomEvent.CONTROL, ControlEventInstruction.TOGGLE_MIRROR)
  }

  return (
    <div>
      <button onClick={continueDetection}>Continue detection</button>
      <button onClick={switchCamera}>Switch camera</button>
      <button onClick={toggleMirror}>Mirror camera</button>
    </div>
  )
}

Without importing @innovatrics/dot-face-auto-capture/events you can use values of FaceCustomEvent and ControlEventInstruction directly.

const continueDetection = () => {
  document.dispatchEvent(
    new CustomEvent("face-auto-capture:control", {
      detail: { instruction: "continue-detection" },
    }),
  );
}

ComponentCustomEvent.REQUEST_CAPTURE

  • enum RequestCaptureInstruction

    • FIRST_FRAME = 'first-frame' - Notifies Face Auto Capture to capture the very first image right after capturing this event. Validation and detection results are not evaluated in the process

    • FIRST_VALID_FRAME = 'first-valid-frame' - Notifies Face Auto Capture to capture the very first valid image right after capturing this event. Validation and detection results are evaluated in the process

import { dispatchCaptureEvent, ComponentCustomEvent, RequestCaptureInstruction } from "@innovatrics/dot-face-auto-capture/events";

export const Dispatch = () => {

  const captureAnyImage = () => {
    dispatchCaptureEvent(ComponentCustomEvent.REQUEST_CAPTURE, RequestCaptureInstruction.FIRST_FRAME)
  }

  const captureValidImage = () => {
    dispatchCaptureEvent(ComponentCustomEvent.REQUEST_CAPTURE, RequestCaptureInstruction.FIRST_VALID_FRAME)
  }

  return (
    <div>
      <button onClick={captureAnyImage}>Capture any image</button>
      <button onClick={captureValidImage}>Capture valid image</button>
    </div>
  )
}

Without importing @innovatrics/dot-face-auto-capture/events you can use values of ComponentCustomEvent and RequestCaptureInstruction directly.

const captureAnyImage = () => {
  document.dispatchEvent(
    new CustomEvent("dot-custom-event:request-capture", {
      detail: { instruction: "first-frame" },
    }),
  );
}

const captureValidImage = () => {
  document.dispatchEvent(
    new CustomEvent("dot-custom-event:request-capture", {
      detail: { instruction: "first-valid-frame" },
    }),
  );
}

Example of using components together

import type { FaceCallback } from "@innovatrics/dot-face-auto-capture";
import {
  dispatchControlEvent,
  FaceCustomEvent,
  ControlEventInstruction
} from "@innovatrics/dot-face-auto-capture/events";

import FaceCamera from "./FaceCamera";
import FaceUi from "./FaceUi";

const FaceAutoCapture = () => {
  const handlePhotoTaken: FaceCallback = ({ image, data }, content) => {
    console.log(image, data);
  }

  const handleError = (error: Error) => {
    alert(error);
  };

  const handleContinueDetection = () => {
    dispatchControlEvent(FaceCustomEvent.CONTROL, ControlEventInstruction.CONTINUE_DETECTION)
  };

  return (
    <div>
      <button onClick={handleContinueDetection}>Continue detection</button>
      <div style={{ position: "relative" }}>
        <FaceUi />
        <FaceCamera
          cameraFacing="user"
          onPhotoTaken={handlePhotoTaken}
          onError={handleError}
        />
      </div>
    </div>
  );
};

Code Samples

See also DOT Web Samples showing the usage of DOT Web Auto Capture components in different front-end technologies like React, Angular…​

Appendix

Changelog

6.2.0 - 2024-11-06

Added
  • captureMode property to switch between AUTOCAPTURE and WAIT_FOR_REQUEST capture mode

  • dot-custom-event:request-capture event to trigger capture in WAIT_FOR_REQUEST mode

  • iengine.lic as another default license file name. Now the component will automatically load either iengine.lic or license.lic

Changed
  • license.lic default license file name flagged as deprecated

Fixed
  • Custom element prop types

6.1.8 - 2024-10-01

Fixed
  • Wrong image in onPhotoTaken callback

6.1.7 - 2024-10-01

Fixed
  • Error while switching between cameras on Android devices

6.1.6 - 2024-09-11

Fixed
  • Theme customization prop

6.1.5 - 2024-09-02

Changed
  • Improved security measures and enhanced protection against vulnerabilities

6.1.4 - 2024-08-21

Fixed
  • camera initialization on iOS, when multiple components are used on the same page

6.1.3 - 2024-08-21

Fixed
  • unnecessary camera permission request when photo was taken

6.1.2 - 2024-08-07

Added
  • ref property to custom HTMLElement type

6.1.1 - 2024-08-01

  • Incremental version upgrade

6.1.0 - 2024-07-09

Added
  • font size, family, weight and style customization

Changed
  • Update SAM to version 1.39.3

  • Improved detection of face size

6.0.0 - 2024-05-27

Added
  • License validation

  • dot_embedded_bg.wasm - WASM binary file for license validation

  • licensePath - path to license file

  • Tiers - freemium/premium mode

  • Freemium overlay component Non-UI components

Changed
  • Update SAM to version 1.38.1

5.2.8 - 2024-04-10

Changed
  • Performance and documentation optimization

5.2.7 - 2024-03-01

Changed
  • Performance and documentation optimization

5.2.6 - 2024-02-20

Changed
  • Fix typo in package.json

5.2.5 - 2024-02-20

Changed
  • Remove type:module from package.json file in order to fix issue with Angular 16

5.2.4 - 2024-02-14

Fixed
  • Component not loading in certain conditions on Android in Firefox

5.2.3 - 2023-12-14

Added
  • styleTarget property for specifying an alternate DOM node to inject styles. This is useful when rendering components in a shadow DOM. If not specified, the styles are injected into the <head> element of the document.

5.2.2 - 2023-11-27

Removed
  • Use of eval() function in third-party library

5.2.1 - 2023-10-18

Changed
  • Update SAM to version 1.35.3

  • Improved detection speed

  • Minimum camera resolution validation changed from validating both sides to validating just the shorter side. Now, minimal size of the shorter side is 720px.

5.2.0 - 2023-10-03

Changed
  • Update SAM to version 1.35.0

  • Improved detection speed

Added
  • wasmDirectoryPath - path to directory with Web assembly files.

  • Support for multiple Web assembly files. The component will automatically load the sam.wasm or sam_simd.wasm files from the specified folder, based on the device support of SIMD instructions. Web assembly files have to be placed in wasm folder.

Removed
  • samWasmUrl - property was removed. Use wasmDirectoryPath property instead.

5.1.0 - 2023-09-28

Changed
  • isDeviceTiltWithinBoundsValidator validator for detecting device pitch renamed to isDevicePitchWithinBoundsValidator

  • TILT_ANGLE_THRESHOLD default threshold value renamed to`DEVICE_PITCH_ANGLE_THRESHOLD`

  • tiltAngleThreshold property for customizing allowed device tilt renamed to devicePitchAngleThreshold

5.0.4 - 2023-09-26

  • Update content parameter of onPhotoTaken callback

5.0.3 - 2023-09-21

Changed
  • Disable SwitchCamera button when component is in candidate_selection phase

5.0.2 - 2023-09-20

  • Incremental version upgrade

5.0.1 - 2023-08-25

Fixed
  • Detector unable to initialize

5.0.0 - 2023-08-17

Changed
  • The onPhotoTaken callback change: Image and image data are returned as first parameter. Second parameter is a Record that represents a signed version of the image.

  • Improvements in UI package, new SwitchCamera button icon.

  • Unify thresholds to double-precision floating point format: FACE_SHARPNESS_THRESHOLD, FACE_BRIGHTNESS_LOW_THRESHOLD, FACE_BRIGHTNESS_HIGH_THRESHOLD.

  • Changed default value of MIN_FACE_SIZE_RATIO to 0.16, MAX_FACE_SIZE_RATIO to 0.20, FACE_SHARPNESS_THRESHOLD to 0.3 and FACE_BRIGHTNESS_LOW_THRESHOLD to 0.25.

  • Long instruction text wraps to multiple lines. If text is longer than 34 characters.

Added
  • Backdrop for the default face placeholder.

  • backdropColor property for changing the color of the default face placeholder backdrop

  • sessionIdForBinaryContent property for generating byte array data

  • isDeviceTiltWithinBoundsValidator validator for detecting device tilt (pitch)

  • TILT_ANGLE_THRESHOLD default threshold value

  • tiltAngleThreshold property for customizing allowed device tilt

  • device_tilted instruction code and appropriate default message

Removed
  • cameraSettings parameter from onPhotoTaken callback

  • imageType property. Component returns result image in jpeg format.

Fixed
  • Calculating font size and camera button properties

4.1.6 - 2023-08-14

  • Security update

4.1.5 - 2023-07-03

Fixed
  • declaration files for Typescript version 5 in UI package

4.1.4 - 2023-06-21

Fixed
  • declaration files for Typescript version 5

4.1.3 - 2023-05-02

  • Incremental version upgrade

4.1.2 - 2023-03-31

  • Incremental version upgrade

4.1.1 - 2023-03-27

  • Incremental version upgrade

4.1.0 - 2023-03-24

Changed
  • Improvements in face detection

  • FACE_BRIGHTNESS_LOW_THRESHOLD lowered from 400 to 300

Fixed
  • UI component occasionally started in candidate_selection phase after receiving continue-detection event

Changed
  • detection crop ratio 4:3

Add
  • Component version in debug layer

4.0.4 - 2023-03-15

Fixed
  • Build package in umd format

  • FacePlaceholderIcon changed from enum to union type

  • AppState changed from enum to readonly object

4.0.3 - 2023-03-07

Fixed
  • Detection not initialized on slow internet connection. Component remains in "waiting" state

  • "Candidate selection phase" at the beginning of detection when detecting multiple captures

  • applied text-align: center on instruction component on small screen

4.0.2 - 2023-02-23

Changed
  • changed instruction when face_not_present

4.0.1 - 2023-01-19

Fixed
  • export events from @innovatrics/dot-face-auto-capture/events

4.0.0 - 2023-01-18

Removed
  • UI layer from camera component (buttons, placeholder, instruction, app state overlay and detection layer)

  • center face validator

  • FACE_CENTERING_NARROW_SIDE threshold

  • FACE_CENTERING_WIDE_SIDE threshold

Added
  • UI package with placeholder, instructions, buttons and detection layer

  • Custom events and events listeners for communication from app to component (switch-camera, toggle-mirror)

  • Custom events and events listeners for communication from components to app (camera-resolution-changed, instruction-changed, detected-document-changed, state-changed)

  • detection layer with detected face circle

  • showDetectionLayer switch for show/hide camera buttons (switch camera, toggle mirror)

  • showCameraButtons switch for show/hide detection layer

  • OutOfBounds validator

  • outOfBoundsValidationRectangle

  • outOfBoundsDetectionPoints

  • all rectangles and points into debug layer

  • SAM version into debug layer

Changed
  • Rename photoTakenCb to onPhotoTaken

  • Order of instruction processing. Before validating the centering of the detected face, the size of the detected face is validated.

  • Component is now build as umd and es module

  • Camera buttons (switch camera, toggle mirror) are now hidden by default

3.5.2 - 2022-12-16

Fixed
  • Camera switch on Android devices with Firefox

3.5.1 - 2022-10-13

Fixed
  • Memoized props from first instance which holds reference to callback function from initialization on every capture

3.5.0 - 2022-10-10

Changed
  • Best candidate selection by sharpness

  • Dynamic candidate selection phase duration

  • Center face narrow side validator from 0.07 to 0.12

Fixed
  • Minimal camera resolution check

  • Selection of best image in candidate selection phase entering

Removed
  • Hotspots validator with hotspotsMediumThreshold and number hotspotsHighThreshold

3.4.3 - 2022-09-28

Fixed
  • Possible false candidate selection on first frame after entering candidate selection

3.4.2 - 2022-08-10

Fixed
  • Typescript declaration files export

3.4.1 - 2022-08-09

Fixed
  • Typescript declaration files export

Change
  • Dependencies update and upgrade

3.3.1 - 2022-07-04

Fixed
  • Zero height of component when error occurs

Add
  • add appStateInstructions property to uiCustomisation

  • add option to change appState instructions text and visibility

Change
  • interface for changing Loading appState instruction text

3.3.0 - 2022-06-03

Added
  • Add support for capturing multiple face photos

  • Add custom event face-auto-capture with continue-detection instruction to continue detection

Changed
  • When photoTakenCb is called, component switches into waiting state

  • Parent of <x-dot-face-auto-capture /> does not have to have a defined height

3.2.0 - 2022-05-23

Added
  • Add Countly analytics tracking

  • Add image parameters (brightness, sharpness, hotspot)

  • Session recording for face detection

Changed
  • onError callback returns AutoCaptureError

  • onError callback is required

  • Show error screen when error occurs

Fixed
  • Stucked component when error occurs

3.1.2 - 2022-04-04

Changed
  • Remove force manual capture on instruction click

3.1.1 - 2022-03-15

Changed
  • Change optimalFaceSizeLimit and optimalFaceSizeParam to minFaceSizeRatio and maxFaceSizeRatio

  • Change faceCenterLimit to faceCenteringNarrowSide and faceCenteringWideSide

  • Set minFaceSizeRatio default value to 0.35 and maxFaceSizeRatio to 0.44

  • Set faceCenteringNarrowSide default value to 0.07 and faceCenteringWideSide to 0.21

3.1.0 - 2022-02-03

Fixed
  • Unify loading and instruction design

3.0.2 - 2022-01-28

Added
  • Add loading screen

  • Add loading.text property in uiCustomisation for configuring text on loading screen

Changed
  • Show new instruction only if 600ms elapsed since last instruction change

3.0.1 - 2022-01-25

Added
  • file sam.wasm

Fixed
  • safari version 15 on mac

Changed
  • Face detection accuracy improved.

  • Detection engine

Removed
  • blaze_models package

  • modelUrls option from cameraOptions

2.3.1 - 2022-01-10

Fixed
  • Fix bug causing integration error

2.3.0 - 2022-01-05

Added
  • add cameraSettings into photoTakenCb callBack function

  • Redesign of the UI of Face Auto Capture component.

Changed
  • photoTakenCb callBack function structure

2.2.2 - 2021-12-17

  • Incremental version upgrade

2.2.1 - 2021-12-09

Changed
  • Hide switch camera button if there is only 1 webcam available

2.2.0 - 2021-11-30

Added
  • thresholds.faceConfidence - Detection confidence threshold with default value 0.12

  • modelUrls - Object with path to the models needed for detection

Changed
  • integrated new neural network for face detection

  • dynamic import of TensorFlow.js libraries

2.1.0 - 2021-11-18

  • First released version