Virtual Background | Agora Docs

Virtual Background enables users to blur their background, or replace it with a solid color or an image. This feature is applicable to use-cases such as online conferences, online classes, and live streaming. It helps protect personal privacy and reduces audience distraction.

Understand the tech

Virtual Background offers the following options:

Feature	Example
Blurred background and image background
Video/Animated background
Portrait-in-picture	Allows the presenter to use slides as the virtual background while superimposing their video. The effect is similar to a weather news cast on television, preventing interruptions during a layout toggle.

Want to test Virtual Background? Try the online demo.

Prerequisites

Ensure that you have implemented the SDK quickstart in your project.

Implement virtual background

This section shows you how to add a virtual background to the local video.

Check device compatibility

To avoid performance degradation or unavailable features when enabling Virtual Background on low-end devices, check whether the device supports the feature.

boolean isFeatureAvailable() {
  return agoraEngine.isFeatureAvailableOnDevice(
    Constants.FEATURE_VIDEO_VIRTUAL_BACKGROUND
  );
}

fun isFeatureAvailable(): Boolean {
  return agoraEngine.isFeatureAvailableOnDevice(
    Constants.FEATURE_VIDEO_VIRTUAL_BACKGROUND
  )
}

Set a blurred background

To blur the video background, use the following code:

void setBlurBackground() {
  VirtualBackgroundSource virtualBackgroundSource = new VirtualBackgroundSource();
  virtualBackgroundSource.setBackgroundSourceType(VirtualBackgroundSource.BACKGROUND_BLUR);
  virtualBackgroundSource.setBlurDegree(VirtualBackgroundSource.BLUR_DEGREE_MEDIUM);

  // Set processing properties for background
  SegmentationProperty segmentationProperty = new SegmentationProperty();
  segmentationProperty.setModelType(SegmentationProperty.SEG_MODEL_AI);
  // Use SEG_MODEL_GREEN if you have a green background
  segmentationProperty.setGreenCapacity(0.5f); // Accuracy for identifying green colors (range 0-1)

  // Enable or disable virtual background
  agoraEngine.enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty);
}

fun setBlurBackground() {
  val virtualBackgroundSource = VirtualBackgroundSource()
  virtualBackgroundSource.setBackgroundSourceType(VirtualBackgroundSource.BACKGROUND_BLUR)
  virtualBackgroundSource.setBlurDegree(VirtualBackgroundSource.BLUR_DEGREE_MEDIUM)

  // Set processing properties for background
  val segmentationProperty = SegmentationProperty()
  segmentationProperty.setModelType(SegmentationProperty.SEG_MODEL_AI)
  // Use SEG_MODEL_GREEN if you have a green background
  segmentationProperty.setGreenCapacity(0.5f) // Accuracy for identifying green colors (range 0-1)

  // Enable or disable virtual background
  agoraEngine.enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty)
}

Set a color background

To apply a solid color as the virtual background, use a hexadecimal color code. For example, 0x0000FF for blue:

void setSolidBackground() {
  VirtualBackgroundSource virtualBackgroundSource = new VirtualBackgroundSource();
  virtualBackgroundSource.setBackgroundSourceType(VirtualBackgroundSource.BACKGROUND_COLOR);
  virtualBackgroundSource.setColor(0x0000FF);

  // Set processing properties for background
  SegmentationProperty segmentationProperty = new SegmentationProperty();
  segmentationProperty.setModelType(SegmentationProperty.SEG_MODEL_AI);
  // Use SEG_MODEL_GREEN if you have a green background
  segmentationProperty.setGreenCapacity(0.5f); // Accuracy for identifying green colors (range 0-1)

  // Enable or disable virtual background
  agoraEngine.enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty);
}

fun setSolidBackground() {
  val virtualBackgroundSource = VirtualBackgroundSource()
  virtualBackgroundSource.setBackgroundSourceType(VirtualBackgroundSource.BACKGROUND_COLOR)
  virtualBackgroundSource.setColor(0x0000FF)

  // Set processing properties for background
  val segmentationProperty = SegmentationProperty()
  segmentationProperty.setModelType(SegmentationProperty.SEG_MODEL_AI)
  // Use SEG_MODEL_GREEN if you have a green background
  segmentationProperty.setGreenCapacity(0.5f) // Accuracy for identifying green colors (range 0-1)

  // Enable or disable virtual background
  agoraEngine.enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty)
}

Set an image background

To set a custom image as the virtual background, specify the absolute path to the image file.

void setImageBackground() {
  VirtualBackgroundSource virtualBackgroundSource = new VirtualBackgroundSource();
  virtualBackgroundSource.setBackgroundSourceType(VirtualBackgroundSource.BACKGROUND_IMG);
  virtualBackgroundSource.setSource("<absolute path to an image file>");

  // Set processing properties for background
  SegmentationProperty segmentationProperty = new SegmentationProperty();
  segmentationProperty.setModelType(SegmentationProperty.SEG_MODEL_AI);
  // Use SEG_MODEL_GREEN if you have a green background
  segmentationProperty.setGreenCapacity(0.5f); // Accuracy for identifying green colors (range 0-1)

  // Enable or disable virtual background
  agoraEngine.enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty);
}

fun setImageBackground() {
  val virtualBackgroundSource = VirtualBackgroundSource()
  virtualBackgroundSource.setBackgroundSourceType(VirtualBackgroundSource.BACKGROUND_IMG)
  virtualBackgroundSource.setSource("<absolute path to an image file>")

  // Set processing properties for background
  val segmentationProperty = SegmentationProperty()
  segmentationProperty.setModelType(SegmentationProperty.SEG_MODEL_AI)
  // Use SEG_MODEL_GREEN if you have a green background
  segmentationProperty.setGreenCapacity(0.5f) // Accuracy for identifying green colors (range 0-1)

  // Enable or disable virtual background
  agoraEngine.enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty)
}

Reset the background

To disable the virtual background and revert to the original video state, use the following code:

void removeBackground() {
  // Disable virtual background
  agoraEngine.enableVirtualBackground(
    false,
    new VirtualBackgroundSource(),
    new SegmentationProperty()
  );
}

fun removeBackground() {
  // Disable virtual background
  agoraEngine.enableVirtualBackground(
    false,
    VirtualBackgroundSource(),
    SegmentationProperty()
  )
}

Reference

This section contains content that completes the information in this page, or points you to documentation that explains other aspects to this product.

API reference

Understand the tech

Virtual Background offers the following options:

Feature	Example
Blurred background and image background
Video/Animated background
Portrait-in-picture	Allows the presenter to use slides as the virtual background while superimposing their video. The effect is similar to a weather news cast on television, preventing interruptions during a layout toggle.

Want to test Virtual Background? Try the online demo.

Prerequisites

Ensure that you have implemented the SDK quickstart in your project.

Implement virtual background

This section shows you how to add a virtual background to the local video.

Check device compatibility

To avoid performance degradation or unavailable features when enabling Virtual Background on low-end devices, check whether the device supports the feature.

guard agoraEngine.isFeatureAvailable(onDevice: .videoPreprocessVirtualBackground) else {
  // Device doesn't support virtual background
  return
}

Set a blurred background

To blur the video background, use the following code:

func blurBackground() {
  let virtualBackgroundSource = AgoraVirtualBackgroundSource()
  virtualBackgroundSource.backgroundSourceType = .blur
  virtualBackgroundSource.blurDegree = .high

  let segData = AgoraSegmentationProperty()
  segData.modelType = .agoraAi

  agoraEngine.enableVirtualBackground(true, backData: virtualBackgroundSource, segData: segData)
}

Set a color background

To apply a solid color as the virtual background, use a hexadecimal color code.

func colorBackground() {
  let virtualBackgroundSource = AgoraVirtualBackgroundSource()
  virtualBackgroundSource.backgroundSourceType = .color
  virtualBackgroundSource.color = convertColorToHex(.red)

  let segData = AgoraSegmentationProperty()
  segData.modelType = .agoraAi

  agoraEngine.enableVirtualBackground(true, backData: virtualBackgroundSource, segData: segData)
}

Set an image background

To set a custom image as the virtual background, specify the absolute path to the image file.

func imageBackground() {
  let virtualBackgroundSource = AgoraVirtualBackgroundSource()
  virtualBackgroundSource.backgroundSourceType = .img
  virtualBackgroundSource.source = Bundle.main.path(forResource: "background_ss", ofType: "jpg")

  let segData = AgoraSegmentationProperty()
  segData.modelType = .agoraAi

  agoraEngine.enableVirtualBackground(true, backData: virtualBackgroundSource, segData: segData)
}

Reset the background

To disable the virtual background and revert to the original video state, use the following code:

agoraEngine.enableVirtualBackground(false, backData: nil, segData: nil)

Reference

This section contains content that completes the information in this page, or points you to documentation that explains other aspects to this product.

API reference

Try out the online demo for Virtual background.

Understand the tech

Virtual Background offers the following options:

Feature	Example
Blurred background and image background
Video/Animated background
Portrait-in-picture	Allows the presenter to use slides as the virtual background while superimposing their video. The effect is similar to a weather news cast on television, preventing interruptions during a layout toggle.

Want to test Virtual Background? Try the online demo.

A typical transmission pipeline in the Agora Web SDK consists of a chain of procedures, including capture, preprocessing, encoding, transmitting, decoding, post-processing, and playback. In the preprocessing stage, extensions can modify the audio and video data in the pipeline to implement features such as virtual background and noise cancellation.

Web SDK typical transmission

Prerequisites

Ensure that you have implemented the SDK quickstart in your project.

Implement virtual background

This section shows you how to add a virtual background to the local video.

Complete sample code

Copy the following code into your script file:

Complete sample code for virtual background

// Create Client
var client = AgoraRTC.createClient({mode: "rtc", codec: "vp8"});
// Create VirtualBackgroundExtension instance
const extension = new VirtualBackgroundExtension();
// Register plugin
AgoraRTC.registerExtensions([extension]);

let processor = null;
var localTracks = {
 videoTrack: null,
 audioTrack: null
};

// Initialize
async function getProcessorInstance() {
 if (!processor && localTracks.videoTrack) {
  // Create VirtualBackgroundProcessor instance
  processor = extension.createProcessor();

  try {
  // Initialize plugin
  await processor.init();
  } catch(e) {
   console.log("Fail to load WASM resource!");
   return null;
  }

  // Inject plugin into SDK's video processing pipeline
  localTracks.videoTrack.pipe(processor).pipe(localTracks.videoTrack.processorDestination);
 }
 return processor;
}

// Join channel
async function join() {
 // Add event listeners
 client.on("user-published", handleUserPublished);
 client.on("user-unpublished", handleUserUnpublished);

 [options.uid, localTracks.audioTrack, localTracks.videoTrack] = await Promise.all([
  // Join channel
  client.join(options.appid, options.channel, options.token || null),
  // Create local microphone and camera tracks
  localTracks.audioTrack || AgoraRTC.createMicrophoneAudioTrack(),
  localTracks.videoTrack || AgoraRTC.createCameraVideoTrack({encoderConfig: '720p_4'})
 ]);

 // Play local tracks
 localTracks.videoTrack.play("local-player");
}

// Set solid color background
async function setBackgroundColor() {
 if (localTracks.videoTrack) {
  document.getElementById("loading").style.display = "block";

  let processor = await getProcessorInstance();

  try {
   processor.setOptions({type: 'color', color: '#00ff00'});
   await processor.enable();
  } finally {
   document.getElementById("loading").style.display = "none";
  }

  virtualBackgroundEnabled = true;
 }
}

// Blur user's actual background
async function setBackgroundBlurring() {
 if (localTracks.videoTrack) {
  document.getElementById("loading").style.display = "block";

  let processor = await getProcessorInstance();

  try {
   processor.setOptions({type: 'blur', blurDegree: 2});
   await processor.enable();
  } finally {
   document.getElementById("loading").style.display = "none";
  }

  virtualBackgroundEnabled = true;
 }
}

// Set image background
async function setBackgroundImage() {
  const imgElement = document.createElement('img');

  imgElement.onload = async() => {
   document.getElementById("loading").style.display = "block";

   let processor = await getProcessorInstance();

   try {
    processor.setOptions({type: 'img', source: imgElement});
    await processor.enable();
   } finally {
    document.getElementById("loading").style.display = "none";
   }

   virtualBackgroundEnabled = true;
  }
  imgElement.src = '/images/background.png';
}

Integrate the virtual background extension

Run the following comment in the root directory of your project:

npm install agora-extension-virtual-background

Import the virtual background extension

You can add the extension in your app in the following ways:

Add the following code to the script file:

import VirtualBackgroundExtension from "agora-extension-virtual-background";

Add the following code to the html file:

<script src="../agora-extension-virtual-background.js"></script>

Create and register the extension instance

// Create Client
var client = AgoraRTC.createClient({mode: "rtc", codec: "vp8"});
// Create VirtualBackgroundExtension instance
const extension = new VirtualBackgroundExtension();
// Check compatibility
if (!extension.checkCompatibility()) {
  // The current browser does not support the virtual background plugin, you can stop executing the subsequent logic
  console.error("Does not support Virtual Background!");
}
// Register plugin
AgoraRTC.registerExtensions([extension]);

Inject a processor into the local video stream

Call extension.createProcessor to create a VirtualBackgroundProcessor instance.
```
processor = extension.createProcessor();
```
Call processor.init to initialize the plugin. When resource loading or plug-in initialization fails, this method will throw an exception, and the application can catch the exception and handle it accordingly:
```
await processor.init();
```
After creating the local camera video track, call videoTrack.pipe and specify the videoTrack.processorDestination attribute to inject the plug-in into the SDK's media processing pipeline.

For computing performance reasons, Agora recommends using the virtual background plug-in on a single video track. If you need two video tracks for preview, create multiple instances of VirtualBackgroundProcessor.

localTracks.videoTrack.pipe(processor).pipe(localTracks.videoTrack.processorDestination);

Set a virtual background

Call processor.setOptions to set the virtual background type and corresponding parameters. The following examples show how you use different backgrounds:

Set a solid color background: Set the type parameter to color, then set the color parameter to a color value:
```
processor.setOptions({type: 'color', color: '#00ff00'});
```
Set the picture background: Set the type parameter to img, and then set the source parameter to HTMLImageElement:
```
processor.setOptions({type: 'img', source: HTMLImageElement});
```
Blur the user's actual background: Set the type parameter to blur, and then set the blurDegree parameter to low (1), medium (2), or high (3):
```
processor.setOptions({type: 'blur', blurDegree: 2});
```
Set a dynamic background: Set the type parameter to video, and then set the source parameter to a video object:
```
processor.setOptions({type: 'video', source: HTMLVideoElement});
```

Enable the virtual background

To enable a virtual background, call processor.enable:

await processor.enable();

If enable is not called before calling setOptions, the SDK will enable the background blur effect by default, with a blur level of 1. After turning on the virtual background, if you need to switch the virtual background effect, just adjust setOptions.

Disable the virtual background

To disable the virtual background, call disable and unpipe:

await processor.disable();

To remove the processor from the local video track, call videoTrack.unpipe:

localTracks.videoTrack.unpipe();

If you need to enable the virtual background again, you can reuse the existing VirtualBackgroundProcessor instance and do not need to recreate it. If multiple instances of VirtualBackgroundProcessor are created, it is recommended to call the processor.release method to release the plug-in resources that are no longer needed.

Reference

This section contains content that completes the information in this page, or points you to documentation that explains other aspects to this product.

For a working example, check out the Virtual background web demo and the associated source code.

Considerations

This extension works best when there is only one user in the video captured by the camera.
The browser support for the virtual background extension is as follows:
- To get a better virtual background experience, Agora recommends using this feature on the latest version of Desktop Chrome.
- Agora does not recommend enabling the virtual background feature on Firefox and Safari browsers. Backgrounding the web app on Firefox may cause the video to freeze, while the performance on Safari could be poor due to the browser's own performance issues.
- Agora does not recommend enabling the virtual background feature on mobile browsers.
The virtual background feature has high performance requirements. Make sure your computer meets the following requirements:
- CPU: Intel Core i5 4 cores or higher
- 8G RAM or more
- 64-bit operating system
If multiple extensions are enabled concurrently and other programs are occupying high system resources at the same time, your app may experience audio and video freezes.
When using this extension, Agora recommends selecting Performance mode or Balanced mode for your laptops. The computing requirements for this extension may not be met if the laptop is in a battery-saving mode.
This extension supports using a video as a dynamic virtual background since v1.0.0-beta-3. Videos must be in a format supported by <video> HTML elements. Agora also recommends meeting the following requirements:
- The video adopts a resolution close to that of a portrait. Agora recommends not using a video with too high a bit rate.
- Video content is suitable for looping to achieve a more natural dynamic virtual background effect.
- Properly reduce the video frame rate, such as 15 fps or below. Video above 30 fps is not recommended by Agora.

API reference

IVirtualBackgroundExtension

createProcessor

createProcessor(): IVirtualBackgroundProcessor;

Creates a VirtualBackgroundProcessor object.

IVirtualBackgroundProcessor

init

init(wasmDir: string): Promise<void>;

Initializes the extension.

Parameters:

wasmDir: The URL where the virtual background WASM module is located (without the WASM filename). Starting from v1.2.0, this parameter is optional.

If the initialization of the extension fails due to the failure to access the Wasm file, this method throws an exception. Agora recommends that you disable the virtual background feature catching the exception.

If the Wasm file is deployed on third-party services such as CDN and OSS across domains, you need to enable cross-domain access. For example, when deploying Nginx servers across domains, to enable cross-domain access, add the following configurations:

add_header 'Access-Control-Allow-Origin' "$http_origin";
add_header 'Access-Control-Allow-Credentials' "true";

setOptions

setOptions(options: VirtualBackgroundEffectOptions): void;

Chooses the virtual background type, and sets parameters.

Parameters:

options: The virtual background options. See VirtualBackgroundEffectOptions.

enable

enable(): void | Promise<void>;

Enables the virtual background feature.

If you do not call setOptions before calling this method, the default behavior of the SDK is to blur users' actual background with the blurring degree set as 1.

disable

disable(): void | Promise<void>;

Disables the virtual background feature.

release

release(): Promise<void>;

Releases all resources used by the extension, including created web workers .

If IVirtualBackgroundProcessor is repeatedly created without releasing the resources occupied by the extension, it may cause memory exhaustion.

onoverload

onoverload?: () => void;

When the system performance cannot meet the processing requirements, the SDK triggers onoverload.

Agora recommends calling disable in this event to disable virtual background and adding a UI prompt.

Type definition

VirtualBackgroundEffectOptions

Virtual background types and settings. Used in the setOptions method.

export type VirtualBackgroundEffectOptions = {
 type: string,
 color?: string;
 source?: HTMLImageElement;
 blurDegree?: Number;
};

Properties:

type: String. Choose the virtual background type:
- "color": Sets a solid color as the background.
- "img": Sets an image as the background.
- "blur": Blurs the user's original background.
- "video": Sets a video as the dynamic background.
- "none": Removes the background, that is, creates the effect of a portrait cutout.
color: String. When you set type as "color", set this parameter to specify the color. The value must be a valid CSS color such as "white", "#00ff00", or "RGB(255, 0, 0)".
source: The HTMLImageElement object. When you set type as "img", you can set a custom background image through this parameter.

If the error "texture bound to texture unit 2 is not renderable. It might be non-power-of-2 or have incompatible texture filtering (maybe)?" occurs, check whether the product of the picture's width and height is a multiple of 2.
Due to the restriction of browsers' security policy, if your background image resources are deployed across domains, you need to enable your servers' cross-domain permission and set the crossOrigin property of the HTMLImageElement object as anonymous.
Since it takes time to load the image in the HTMLImageElement object, Agora recommends calling setOptions in the onload callback of the HTMLImageElement object, otherwise, the background momentarily turns black.

blurDegree: Number. When you set type as "blur", set this parameter to choose the blurring degree:
- 1: Low
- 2: Medium
- 3: High
fit: String. Set this parameter to choose how the virtual background is filled:
- "contain": Fill in proportion to ensure that the background can be displayed completely, and fill the insufficient part with black.
- "cover": Fill in proportion and ensure that the background can fill the area, and the excess part will be cropped.
- "fill": Stretch to fill the area.

Understand the tech

Virtual Background offers the following options:

Feature	Example
Blurred background and image background
Video/Animated background
Portrait-in-picture	Allows the presenter to use slides as the virtual background while superimposing their video. The effect is similar to a weather news cast on television, preventing interruptions during a layout toggle.

Want to test Virtual Background? Try the online demo.

Prerequisites

Ensure that you have implemented the SDK quickstart in your project.

Implement virtual background

This section shows you how to add a virtual background to the local video.

Check device compatibility

To avoid performance degradation or unavailable features when enabling Virtual Background on low-end devices, check whether the device supports the feature.

if (!(m_rtcEngine->isFeatureAvailableOnDevice(FeatureType::VIDEO_VIRTUAL_BACKGROUND)))
{
  AfxMessageBox(L"Device doesn't support virtual background");
  return;
}

Set a blurred background

To blur the video background, use the following code:

void SetBackgroundBlur(VirtualBackgroundSource& virtualBackgroundSource) {

  VirtualBackgroundSource virtualBackgroundSource;
  SegmentationProperty segmentationProperty;

  // Set background blur
  virtualBackgroundSource.background_source_type = VirtualBackgroundSource:BACKGROUND_BLUR;
  virtualBackgroundSource.blur_degree = VirtualBackgroundSource::BLUR_DEGREE_HIGH;

  // Set processing properties for background
  segmentationProperty.modelType = SegmentationProperty::SEG_MODEL_AI;

  segmentationProperty.greenCapacity = 0.5F;
  // Enable or disable virtual background
  m_rtcEngine->enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty);
}

Set a color background

To apply a solid color as the virtual background, use a hexadecimal color code. For example, 0x0000FF for blue:

void SetBackgroundColor(VirtualBackgroundSource& virtualBackgroundSource) {

  VirtualBackgroundSource virtualBackgroundSource;
  SegmentationProperty segmentationProperty;

  // Set a solid background color
  virtualBackgroundSource.background_source_type = VirtualBackgroundSource::BACKGROUND_COLOR;
  virtualBackgroundSource.color = 0x0000FF;

  // Set processing properties for background
  segmentationProperty.modelType = SegmentationProperty::SEG_MODEL_AI;

  segmentationProperty.greenCapacity = 0.5F;
  // Enable or disable virtual background
  m_rtcEngine->enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty);
}

Set an image background

To set a custom image as the virtual background, specify the absolute path to the image file.

void SetBackgroundImage(VirtualBackgroundSource& virtualBackgroundSource) {

  VirtualBackgroundSource virtualBackgroundSource;
  SegmentationProperty segmentationProperty;

  // Set a background image
  virtualBackgroundSource.background_source_type = VirtualBackgroundSource::BACKGROUND_IMG;
  virtualBackgroundSource.source = "<absolute path to an image file>";

  // Set processing properties for background
  segmentationProperty.modelType = SegmentationProperty::SEG_MODEL_AI;

  segmentationProperty.greenCapacity = 0.5F;
  // Enable or disable virtual background
  m_rtcEngine->enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty);
}

Reset the background

To disable the virtual background and revert to the original video state, use the following code:

void ResetVirtualBackground() {
  // Set a default or reset state for the virtual background
  VirtualBackgroundSource virtualBackgroundSource;
  SegmentationProperty segmentationProperty;

  // For example, setting a default background color
  virtualBackgroundSource.background_source_type = VirtualBackgroundSource::BACKGROUND_COLOR;
  virtualBackgroundSource.color = 0xFFFFFF;

  // Set processing properties for background
  segmentationProperty.modelType = SegmentationProperty::SEG_MODEL_AI;
  segmentationProperty.greenCapacity = 0.5F;

  // Disable virtual background
  m_rtcEngine->enableVirtualBackground(false, virtualBackgroundSource, segmentationProperty);
}

Reference

This section contains content that completes the information in this page, or points you to documentation that explains other aspects to this product.

API reference

Understand the tech

Virtual Background offers the following options:

Feature	Example
Blurred background and image background
Video/Animated background
Portrait-in-picture	Allows the presenter to use slides as the virtual background while superimposing their video. The effect is similar to a weather news cast on television, preventing interruptions during a layout toggle.

Want to test Virtual Background? Try the online demo.

Prerequisites

Ensure that you have implemented the SDK quickstart in your project.

Implement virtual background

This section shows you how to add a virtual background to the local video.

Enable the extension

To enable the Virtual Background extension, use the following code:

this.engine?.enableExtension(
  'agora_video_filters_segmentation',
  'portrait_segmentation',
  true
 );

Check device compatibility

To avoid performance degradation or unavailable features when enabling Virtual Background on low-end devices, check whether the device supports the feature.

if (!(this.engine?.isFeatureAvailableOnDevice(FeatureType.VIDEO_VIRTUAL_BACKGROUND)))
{
  console.log("Device doesn't support virtual background");
  return;
}

Set a blurred background

To blur the video background, use the following code:

public setBackgroundBlur = () => {
  this.engine?.enableVirtualBackground(true, BackgroundSourceType.BackgroundBlur, {
    blur_degree: BackgroundBlurDegree.BlurDegreeHigh
  });
};

Set a color background

To apply a solid color as the virtual background, use a hexadecimal color code. For example, 0x0000FF for blue:

public setBackgroundColor = () => {
  this.engine?.enableVirtualBackground(true, BackgroundSourceType.BackgroundColor, {
    color: 0x0000FF
  });
};

Set an image background

To set a custom image as the virtual background, specify the absolute path to the image file.

public setBackgroundImage = (imagePath: string) => {
  this.engine?.enableVirtualBackground(true, BackgroundSourceType.BackgroundImg, {}, {}, imagePath);
};

Reset the background

To disable the virtual background and revert to the original video state, use the following code:

private disableVirtualBackground = () => {
  this.engine?.enableVirtualBackground(false, {}, {});
};

Reference

This section contains content that completes the information in this page, or points you to documentation that explains other aspects to this product.

API reference

Understand the tech

Virtual Background offers the following options:

Feature	Example
Blurred background and image background
Video/Animated background
Portrait-in-picture	Allows the presenter to use slides as the virtual background while superimposing their video. The effect is similar to a weather news cast on television, preventing interruptions during a layout toggle.

Want to test Virtual Background? Try the online demo.

Prerequisites

Ensure that you have implemented the SDK quickstart in your project.

Implement virtual background

This section shows you how to add a virtual background to the local video.

Check device compatibility

To avoid performance degradation or unavailable features when enabling Virtual Background on low-end devices, check whether the device supports the feature.

if (!await _engine.isFeatureAvailableOnDevice(FeatureType.videoVirtualBackground)) {
  return;
}

Set a blurred background

To blur the video background, use the following code:

Future<void> setBlurBackground() async {
  final virtualBackgroundSource = const VirtualBackgroundSource(
    backgroundSourceType: BackgroundSourceType.backgroundBlur,
    blurDegree: BackgroundBlurDegree.blurDegreeHigh,
  );

  final segmentationProperty = const SegmentationProperty(
    modelType: SegModelType.segModelAi,
    greenCapacity: 0.5,
  );

  // Enable or disable virtual background
  _engine.enableVirtualBackground(
    enabled: true,
    backgroundSource: virtualBackgroundSource,
    segproperty: segmentationProperty);
}

Set a color background

To apply a solid color as the virtual background, use a hexadecimal color code. For example, 0x0000FF for blue:

Future<void> setColorBackground() async {
  final virtualBackgroundSource = const VirtualBackgroundSource(
    backgroundSourceType: BackgroundSourceType.backgroundColor,
    color: 0x0000FF,
  );

  final segmentationProperty = const SegmentationProperty(
    modelType: SegModelType.segModelAi,
    greenCapacity: 0.5,
  );

  // Enable or disable virtual background
  _engine.enableVirtualBackground(
    enabled: true,
    backgroundSource: virtualBackgroundSource,
    segproperty: segmentationProperty);
}

Set an image background

To set a custom image as the virtual background, specify the path to the image file.

Future<void> setImageBackground() async {
  final virtualBackgroundSource = const VirtualBackgroundSource(
    backgroundSourceType: BackgroundSourceType.backgroundImg,
    source: "<path to an image file>",
  );

  final segmentationProperty = const SegmentationProperty(
    modelType: SegModelType.segModelAi,
    greenCapacity: 0.5,
  );

  // Enable or disable virtual background
  _engine.enableVirtualBackground(
    enabled: true,
    backgroundSource: virtualBackgroundSource,
    segproperty: segmentationProperty);
}

Reset the background

To disable the virtual background and revert to the original video state, use the following code:

Future<void> resetVirtualBackground() async {
  await enableVirtualBackground( false,
    const VirtualBackgroundSource(),
    const SegmentationProperty(),
  );
}

Reference

This section contains content that completes the information in this page, or points you to documentation that explains other aspects to this product.

API reference

Understand the tech

Virtual Background offers the following options:

Feature	Example
Blurred background and image background
Video/Animated background
Portrait-in-picture	Allows the presenter to use slides as the virtual background while superimposing their video. The effect is similar to a weather news cast on television, preventing interruptions during a layout toggle.

Want to test Virtual Background? Try the online demo.

Prerequisites

Ensure that you have implemented the SDK quickstart in your project.

Implement virtual background

This section shows you how to add a virtual background to the local video.

Enable the extension

To enable the Virtual Background extension, use the following code:

agoraEngineRef.current?.enableExtension(
  'agora_video_filters_segmentation',
  'portrait_segmentation',
  true,
);

Set a blurred background

To blur the video background, use the following code:

const setBlurBackground = () => {
  backgroundSourceType = BackgroundSourceType.BackgroundBlur;
  backgroundBlurDegree = BackgroundBlurDegree.BlurDegreeHigh;
  agoraEngineRef.current?.enableVirtualBackground(
    true,
    {
      background_source_type: backgroundSourceType,
      blur_degree: backgroundBlurDegree,
    },
    {},
  );
};

Set a color background

To apply a solid color as the virtual background, use a hexadecimal color code. For example, 0x0000FF for blue:

const setColorBackground = () => {
  backgroundSourceType = BackgroundSourceType.BackgroundColor;
  color = 0x0000ff;
  agoraEngineRef.current?.enableVirtualBackground(
    true,
    {
      background_source_type: backgroundSourceType,
      color: color,
    },
    {},
  );
};

Set an image background

To set a custom image as the virtual background, specify the absolute path to the image file.

const setImageBackground = () => {
  backgroundSourceType = BackgroundSourceType.BackgroundImg;
  source =
    '<<absolute path to an image file>>';
  agoraEngineRef.current?.enableVirtualBackground(
    true,
    {
      background_source_type: backgroundSourceType,
      source: source,
    },
    {},
  );
};

Reset the background

To disable the virtual background and revert to the original video state, use the following code:

const resetVirtualBackground = () => {
  setVirtualBackgroundStatus(false);
  agoraEngineRef.current?.enableVirtualBackground(false, {}, {});
};

Reference

This section contains content that completes the information in this page, or points you to documentation that explains other aspects to this product.

API reference

Understand the tech

Virtual Background offers the following options:

Feature	Example
Blurred background and image background
Video/Animated background
Portrait-in-picture	Allows the presenter to use slides as the virtual background while superimposing their video. The effect is similar to a weather news cast on television, preventing interruptions during a layout toggle.

Want to test Virtual Background? Try the online demo.

Prerequisites

Ensure that you have implemented the SDK quickstart in your project.

Implement virtual background

This section shows you how to add a virtual background to the local video.

Check device compatibility

To avoid performance degradation or unavailable features when enabling Virtual Background on low-end devices, check whether the device supports the feature.

private bool IsFeatureAvailable() {
  return agoraEngine.IsFeatureAvailableOnDevice(FeatureType.VIDEO_VIRTUAL_BACKGROUND);
}

Set a blurred background

To blur the video background, use the following code:

private void SetBackgroundBlur()
{
  if(IsFeatureAvailable() == false)
  {
    Debug.Log("Device does not support the virtual background feature");
    return;
  }

  VirtualBackgroundSource virtualBackgroundSource = new VirtualBackgroundSource();

  // Set background blur
  virtualBackgroundSource.background_source_type = BACKGROUND_SOURCE_TYPE.BACKGROUND_BLUR;
  virtualBackgroundSource.blur_degree = BACKGROUND_BLUR_DEGREE.BLUR_DEGREE_HIGH;

  // Set processing properties for background
  SegmentationProperty segmentationProperty = new SegmentationProperty();
  segmentationProperty.modelType = SEG_MODEL_TYPE.SEG_MODEL_AI; // Use SEG_MODEL_GREEN if you have a green background
  segmentationProperty.greenCapacity = 0.5F; // Accuracy for identifying green colors (range 0-1)

  // Enable or disable virtual background
  agoraEngine.EnableVirtualBackground(true, virtualBackgroundSource, segmentationProperty, MEDIA_SOURCE_TYPE.PRIMARY_CAMERA_SOURCE);
}

Set a color background

To apply a solid color as the virtual background, use a hexadecimal color code. For example, 0x0000FF for blue:

private void SetBackgroundColor()
{
  if(IsFeatureAvailable() == false)
  {
    Debug.Log("Device does not support the virtual background feature");
    return;
  }

  VirtualBackgroundSource virtualBackgroundSource = new VirtualBackgroundSource();

  // Set a solid background color
  virtualBackgroundSource.background_source_type = BACKGROUND_SOURCE_TYPE.BACKGROUND_COLOR;
  virtualBackgroundSource.color = 0x0000FF;

  // Set processing properties for background
  SegmentationProperty segmentationProperty = new SegmentationProperty();
  segmentationProperty.modelType = SEG_MODEL_TYPE.SEG_MODEL_AI; // Use SEG_MODEL_GREEN if you have a green background
  segmentationProperty.greenCapacity = 0.5F; // Accuracy for identifying green colors (range 0-1)

  // Enable or disable virtual background
  agoraEngine.EnableVirtualBackground(true, virtualBackgroundSource, segmentationProperty, MEDIA_SOURCE_TYPE.PRIMARY_CAMERA_SOURCE);
}

Set an image background

To set a custom image as the virtual background, specify the absolute path to the image file.

private void SetBackgroundImage()
{
  if(IsFeatureAvailable() == false)
  {
    Debug.Log("Device does not support the virtual background feature");
    return;
  }

  VirtualBackgroundSource virtualBackgroundSource = new VirtualBackgroundSource();

  virtualBackgroundSource.background_source_type = BACKGROUND_SOURCE_TYPE.BACKGROUND_IMG;
  string filePath = Path.Combine(Application.persistentDataPath, "<path-of-the-file>.png");
#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
    filePath = filePath.Replace('/', '\\');
#endif
  virtualBackgroundSource.source = filePath;

  var segproperty = new SegmentationProperty();
  RtcEngine.EnableVirtualBackground(true, virtualBackgroundSource, segproperty, MEDIA_SOURCE_TYPE.PRIMARY_CAMERA_SOURCE);
}

Reset the background

Resets the virtual background, disabling any applied effects and reverting to the original video state.

private void DisableVirtualBackground()
{
  VirtualBackgroundSource virtualBackgroundSource = new VirtualBackgroundSource();
  var segproperty = new SegmentationProperty();
  RtcEngine.EnableVirtualBackground(false, virtualBackgroundSource, segproperty, MEDIA_SOURCE_TYPE.PRIMARY_CAMERA_SOURCE);
}

Reference

This section contains content that completes the information in this page, or points you to documentation that explains other aspects to this product.

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