Table of Contents

Class ImageOverlayVideoEffect

Namespace
VisioForge.Core.Types.X.VideoEffects
Assembly
VisioForge.Core.dll

Represents an image overlay effect that composites static images (watermarks, logos) onto video frames.

public class ImageOverlayVideoEffect : BaseVideoEffect, IBaseVideoEffect, IVideoEditXVideoEffect

Inheritance

Implements

Inherited Members

Remarks

SDK Availability: VideoCaptureCoreX, MediaPlayerCoreX, VideoEditCoreX, Media Blocks SDK

Platform Support: Windows, Linux, macOS, Android, iOS

The image overlay effect provides simple image compositing capabilities for adding watermarks, logos, or other static graphics to video. Supports common image formats (PNG, JPG, GIF) with alpha channel transparency for PNG images. Position and size can be controlled with pixel precision.

Supported Image Formats:

  • PNG: With alpha channel transparency support
  • JPEG: Opaque images
  • GIF: Static and animated
  • BMP: Basic bitmap format

Key Features:

  • Alpha Blending: Adjustable transparency (0.0-1.0)
  • Positioning: Pixel-perfect X/Y coordinate placement
  • Sizing: Custom width and height (auto-detected from image by default)
  • Time Control: Optional start/stop time for VideoEditCoreX

For Classic SDK equivalent, see VideoEffectImageLogo (Windows only). For more advanced overlay capabilities with animations and multiple layers, consider using the OverlayManager system.

Performance Note: Image decoding happens at initialization. Runtime performance is efficient for static overlays. For multiple overlays or animated effects, use OverlayManager for better performance.

Constructors

ImageOverlayVideoEffect(string, string)

Initializes a new instance of the VisioForge.Core.Types.X.VideoEffects.ImageOverlayVideoEffect class.

public ImageOverlayVideoEffect(string filename, string name = "image-overlay")

Parameters

filename string

The filename.

name string

The name.

Fields

DefaultName

The default name.

public static string DefaultName

Field Value

string

Properties

Alpha

Gets or sets the alpha transparency value for the overlay.

public double Alpha { get; set; }

Property Value

double

Remarks

This alpha value is combined with the image's own alpha channel (for PNG images). For example, an Alpha value of 0.5 on a PNG with 50% alpha will result in 25% overall opacity.

Filename

Gets or sets the path to the image file to overlay.

public string Filename { get; set; }

Property Value

string

Remarks

When changing the filename at runtime, the image will be reloaded. For best performance, use PNG format with pre-multiplied alpha channel.

Height

Gets or sets the height.

public int Height { get; set; }

Property Value

int

StartTime

Gets or sets the start time.

public TimeSpan StartTime { get; set; }

Property Value

TimeSpan

StopTime

Gets or sets the stop time.

public TimeSpan StopTime { get; set; }

Property Value

TimeSpan

Width

Gets or sets the width.

public int Width { get; set; }

Property Value

int

X

Gets or sets the X coordinate.

public int X { get; set; }

Property Value

int

Y

Gets or sets the Y coordinate.

public int Y { get; set; }

Property Value

int

Methods

GenerateDescription()

Generates the description.

public string GenerateDescription()

Returns

string

A string containing the GStreamer element description for the gdkpixbufoverlay effect.