Table of Contents

Class CVFaceDetectBlock

Namespace
VisioForge.Core.MediaBlocks.OpenCV
Assembly
VisioForge.Core.dll

OpenCV face detection block for identifying and tracking human faces in video streams. This block uses advanced computer vision algorithms including Haar cascades, LBP (Local Binary Patterns), and deep learning models to detect faces in real-time. Provides configurable detection parameters, face tracking capabilities, and event notifications when faces are found. Essential for security systems, attendance tracking, emotion recognition, and interactive applications. Supports multiple face detection simultaneously with bounding box coordinates and confidence scores. Implements the VisioForge.Core.MediaBlocks.MediaBlock. Implements the VisioForge.Core.MediaBlocks.IMediaBlockInternals. Implements the IDisposable.

public class CVFaceDetectBlock : MediaBlock, IMediaBlock, IDisposable, IMediaBlockInternals

Inheritance

Implements

Inherited Members

Extension Methods

Constructors

CVFaceDetectBlock(CVFaceDetectSettings)

Initializes a new instance of the VisioForge.Core.MediaBlocks.OpenCV.CVFaceDetectBlock class with the specified face detection settings.

public CVFaceDetectBlock(CVFaceDetectSettings settings)

Parameters

settings CVFaceDetectSettings

The face detection configuration settings containing algorithm parameters.

Properties

Input

Gets the input pad for connecting video sources to be processed.

public override MediaBlockPad Input { get; }

Property Value

MediaBlockPad

Inputs

Gets all input pads for this face detection block.

public override MediaBlockPad[] Inputs { get; }

Property Value

MediaBlockPad[]

Output

Gets the output pad for connecting to downstream processing blocks.

public override MediaBlockPad Output { get; }

Property Value

MediaBlockPad

Outputs

Gets all output pads for this face detection block.

public override MediaBlockPad[] Outputs { get; }

Property Value

MediaBlockPad[]

Settings

Gets or sets the face detection configuration settings. Defines detection algorithms, sensitivity parameters, and output options.

public CVFaceDetectSettings Settings { get; set; }

Property Value

CVFaceDetectSettings

Type

Gets the media block type identifier.

public override MediaBlockType Type { get; }

Property Value

MediaBlockType

Methods

Build()

Constructs and initializes the OpenCV face detection element within the pipeline. This method creates the face detection filter with the specified algorithm settings, establishes input and output pads, and prepares the block for computer vision processing.

public override bool Build()

Returns

bool

true if the face detection element was successfully built and configured; false if initialization failed.

CleanUp()

Releases all resources and performs cleanup operations for this OpenCV face detection block. This method disposes of the face detection element, unsubscribes from events, and resets the build state.

public void CleanUp()

Dispose(bool)

Releases unmanaged and - optionally - managed resources.

protected override void Dispose(bool disposing)

Parameters

disposing bool

true to release both managed and unmanaged resources; false to release only unmanaged resources.

GetCore()

Gets the core BaseElement wrapper that provides additional functionality around the OpenCV face detection element.

public BaseElement GetCore()

Returns

BaseElement

The BaseElement wrapper instance that encapsulates the face detection functionality.

GetElement()

Gets the underlying GStreamer element that performs the face detection operation.

public Element GetElement()

Returns

Element

The GStreamer Element instance representing the OpenCV face detection filter.

IsAvailable()

Determines whether this media block is available. Correct NuGet SDK redist should be included into your project. Checks for OpenCV library availability and face detection algorithm support.

public static bool IsAvailable()

Returns

bool

true if OpenCV face detection functionality is available; otherwise, false.

ProcessBusMessage(Structure)

Processes GStreamer bus messages for face detection events and notifications. This method handles internal communication and triggers face detection events.

public void ProcessBusMessage(Structure data)

Parameters

data Structure

The GStreamer message data containing detection information.

IMediaBlockInternals.SetContext(MediaBlocksPipeline)

Associates this OpenCV face detection block with a pipeline and initializes its internal context. This method is called internally when the block is added to a pipeline.

void IMediaBlockInternals.SetContext(MediaBlocksPipeline pipeline)

Parameters

pipeline MediaBlocksPipeline

The MediaBlocksPipeline instance that will manage this block.

FaceDetected

Event raised when faces are detected in the video stream. Provides face coordinates, confidence scores, and detection metadata.

public event EventHandler<CVFaceDetectedEventArgs> FaceDetected

Event Type

EventHandler<CVFaceDetectedEventArgs>

See Also