OpenVG at a Glance

OpenVG is an application programming interface (API) for hardware accelerated two-dimensional vector and raster graphics. It provides a device independent and vendor-neutral interface for sophisticated 2D graphical applications, while allowing device manufacturers to provide hardware acceleration on a wide range of devices.

OpenVG 1.1 added a Glyph API and multi-sampled anti-aliasing to the OpenVG 1.0 specification. The OpenVG specification is accompanied by an open source sample implementation and a full suite of conformance tests implemented by the Khronos Group.

The Benefits of an Accelerated Vector Graphics API for Small Screen Devices

Vector graphics are used on a wide diversity of devices that have an urgent need for the smooth and fluidly scalable 2D that high-quality vector graphics provide to create high-quality user interfaces and ultra-readable text on small displays devices. Existing solutions have significant limitations. OpenVG addresses these limitations and provides additional tangible benefits:

Low Power Consumption - An efficient 3D hardware accelerator reduces power consumption by up to 90% compared to a software engine

- An efficient 3D hardware accelerator reduces power consumption by up to 90% compared to a software engine Seamless Transition from Software to Hardware - Enables a seamless transition from efficient software rendering to hardware-accelerated high-quality 2D

- Enables a seamless transition from efficient software rendering to hardware-accelerated high-quality 2D Scalability - Vector graphics provides easy scalability with high-quality rendering, including anti-aliasing, to different screen sizes without multiple bitmaps

- Vector graphics provides easy scalability with high-quality rendering, including anti-aliasing, to different screen sizes without multiple bitmaps Accelerates Existing Formats - Designed to accelerate existing formats (e.g. SVG, PDF, Postscript, Vector fonts, etc.)

- Designed to accelerate existing formats (e.g. SVG, PDF, Postscript, Vector fonts, etc.) Games, Screensavers, Mapping, User Interfaces - Fast scalable anti-aliased vector graphics enables advanced user interfaces, mapping applications, games and screensavers

- Fast scalable anti-aliased vector graphics enables advanced user interfaces, mapping applications, games and screensavers Portable Content - Scalable vector graphics makes it easier to port content across devices and platforms

- Scalable vector graphics makes it easier to port content across devices and platforms Royalty Free - A royalty-free, cross platform API facilitate rapid developer adoption and content creation

Target Applications

SVG Viewers

OpenVG must provide the drawing functionality required for a high performance SVG document viewer that is conformant with version 1.2 of the SVG Tiny profile. It does not need to provide a one-to-one mapping between SVG syntactic features and API calls, but it must provide efficient ways of implementing all SVG Tiny features.

OpenVG must provide the drawing functionality required for a high performance SVG document viewer that is conformant with version 1.2 of the SVG Tiny profile. It does not need to provide a one-to-one mapping between SVG syntactic features and API calls, but it must provide efficient ways of implementing all SVG Tiny features. Portable Mapping Applications

OpenVG can provide dynamic features for map display that would be difficult or impossible to do with an SVG viewer alone, such as dynamic placement and sizing of street names and markers, and efficient viewport culling.

OpenVG can provide dynamic features for map display that would be difficult or impossible to do with an SVG viewer alone, such as dynamic placement and sizing of street names and markers, and efficient viewport culling. E-book Readers

The OpenVG API must provide fast rendering of readable text in Western, Asian, and other scripts. It does not need to provide advanced text layout features.

The OpenVG API must provide fast rendering of readable text in Western, Asian, and other scripts. It does not need to provide advanced text layout features. Games

The OpenVG API must be useful for defining sprites, backgrounds, and textures for use in both 2D and 3D games. It must be able to provide two dimensional overlays (e.g., for maps or scores) on top of 3D content.

The OpenVG API must be useful for defining sprites, backgrounds, and textures for use in both 2D and 3D games. It must be able to provide two dimensional overlays (e.g., for maps or scores) on top of 3D content. Scalable User Interfaces

OpenVG may be used to render scalable user interfaces, particularly for applications that wish to present users with a unique look and feel that is consistent across different screen resolutions.

OpenVG may be used to render scalable user interfaces, particularly for applications that wish to present users with a unique look and feel that is consistent across different screen resolutions. Low-Level Graphics Device Interface

OpenVG may be used as a low-level graphics device interface. Other graphical toolkits, such as windowing systems, may be implemented above OpenVG.

OpenVG API Design Philosophy

Hardware Acceleration Abstraction Layer

that accelerates Bezier curves and texturing can be flexibly implemented. This will allow accelerated performance on a variety of application platforms.

that accelerates Bezier curves and texturing can be flexibly implemented. This will allow accelerated performance on a variety of application platforms. Simplicity

means that functions that are not expected to be accelerated in hardware in the near future were either not included or included as part of the optional VGU utility library.

means that functions that are not expected to be accelerated in hardware in the near future were either not included or included as part of the optional VGU utility library. OpenGL-style syntax

is used where possible, in order to make learning OpenVG as easy as possible for OpenGL developers.

is used where possible, in order to make learning OpenVG as easy as possible for OpenGL developers. Extensibility

makes it possible to add new state variables in order to add new features to the pipeline without needing to add new functions.

makes it possible to add new state variables in order to add new features to the pipeline without needing to add new functions. Focus on Embedded Devices

like mobile phone, game console, DVR, DVD, car navigation, etc.

OpenVG Features

Core API

Coordinate Systems and Transformations (Image drawing uses a 3x3 perspective transformation matrix)

Viewport Clipping, Scissoring and Alpha Masking

Paths

Images

Image Filters

Paint (gradient and pattern)

Blending

The VGU Utility Library

Higher-level Geometric Primitives

Image Warping

OpenVG Rendering Pipeline

The OpenVG pipeline mechanism by which primitives are rendered. Implementations are not required to match the ideal pipeline stage-for-stage; they may take any approach to rendering so long as the final results match the results of the ideal pipeline within the tolerances defined by the conformance testing process.

Stage 1: Path, Transformation, Stroke, and Paint

Stage 2: Stroked Path Generation

Stage 3: Transformation

Stage 4: Rasterization

Stage 5: Clipping and Masking

Stage 6: Paint Generation

Stage 7: Image Interpolation

Stage 8: Blending and Antialiasing

OpenVG Implementations

The following companies have submitted successful conformance tests, demonstrating that their tested products conform to the OpenVG standard. See the Conformant Products List for specific products.