Significant enhancements in quality and efficiency for world’s most widely deployed texture compression technology for mobile and embedded platforms
March 6, 2012 -- Game Developers Conference, San Francisco: Imagination Technologies, a leading multimedia and communications technologies company, announces the release of PVRTC2, the latest generation of its PVRTC texture compression technology, for all PowerVR Series5XT and Series6 GPU IP cores.
The highly acclaimed PVRTC texture compression (TC) format is one of the most widely used texture compression formats in the mobile industry today, implemented in more than 600m devices. It is fully accelerated in hardware on all PowerVR Series4 (MBX), Series 5/5T (SGX) and Series6 (Rogue) GPU cores. PVRTC2 is the first major upgrade of this technology in almost a decade and builds on the many strengths of PVRTC, adding a wide range of new features including:
- Improved image quality, especially for textures with high contrast, large areas of significant colour discontinuity, or boundaries of non-tiling textures
- Better support for pre-multiplied textures.
- Support for arbitrary sized NPOT (Non Power Of Two) textures
Full on-chip hardware-accelerated support for PVRTC2 as well as all previous versions of PVRTC will be available on all PowerVR Series5XT and Series6 GPU cores, and will be fully supported in future releases of all PowerVR reference drivers, and software tools including the PowerVR Insider SDK v2.10 being released at GDC 2012 (7-9th March 2012, stand 618).
Says Tony King-Smith, Vice President marketing for Imagination: “Increasingly in software downloads the total file size is dominated by texture data – indeed up to 70% or more of a top game title may be textures. This has a massive impact on everything from app store download and update times through to device main memory usage. Our PVRTC format has for many years led the way for mobile and embedded devices. Indeed the PVRTC 2bpp (bits per pixel) format is widely acknowledged as the most advanced TC format in mainstream use today, enabling compression of textures stored within an application by up to 16x compared to their uncompressed form.
“PVRTC2 raises the bar yet again for mobile and embedded TC. The addition of sub-texturing, together with significant improvements in quality and NPOT support all further strengthen PowerVR PVRTC – and now PVRTC2 - as the leading TC format of choice for cross-platform, cross-OS textures in leading mobile and embedded platforms, and embedded in the industry’s leading applications.”
Industry support for all standards continues to expand
PowerVR graphics has always supported every major texture compression format on the relevant APIs/platforms, including future formats currently in discussion in Khronos and other groups. Imagination has always been a staunch supporter of open standards, especially the Khronos family of APIs such as OpenGL ES 1 and 2 and the forthcoming ‘Halti’ next generation OpenGL ES API. PowerVR GPUs have always provided full hardware and software driver support for all these formats for all our partners to deliver maximum performance.
Imagination will continue to support any new industry TC formats in both hardware and software as they emerge from Khronos and other sources, however Imagination will always provide support for PVRTC, PVRTC2, and future versions of PVRTC, as a ‘native’ TC format with all its PowerVR GPUs, enabling developers to benefit from the highly optimised relationship between PVRTC and the overall PowerVR GPU architecture.
Maturity over thousands of applications is key
Texture compression is a fundamental tool used by rasterised 3D graphics applications. It performs a very different job to well-known image or video compression standards such as JPEG, PNG or MPEG. When a video or still image is compressed with a standard technique, the main purpose is to achieve the highest possible compression to minimise data storage.
Graphics applications typically access a large set of different textures during execution, with data within any of those textures being potentially requested at random, and such access is not feasible with traditional image compression. Because of these random access requirements, all texture compression techniques introduce some artefacts, such as loss of colour fidelity or visible blocks.
The important issue is that, for a given target bitrate, those artefacts, are as small as possible. This is why it takes many years and thousands of applications to prove any texture compression format performs well under all operating environments.
PVRTC2 delivers the best possible image quality at any given bitrate with much less noticeable artefacts than other solutions.
Major savings in system memory and GPU processing overhead
Not only does texture compression reduce application file size and download times; it also dramatically improves runtime performance and power consumption on mobile platforms such as smartphones and tablets. A good hardware TC decompression implementation minimizes bandwidth needed between the GPU and main memory, by enabling the graphics pipeline to maintain the texture in compressed form at all times. Being able to keep the texture compressed at all times in this way means the cache in the chip effectively becomes several times more effective. In the PowerVR architecture, texture data is only decompressed when needed in the final rendering process, resulting in significant reductions in on-chip bandwidth and processing power. This is one of many reasons why PowerVR PVRTC has been, and continues to be, a key part of every generation of PowerVR graphics architecture, including the forthcoming Series6.
PVRTC2 has both 4bpp and 2bpp variants which have sometimes been abbreviated by users to PVRTC4 and PVRTC2 online as a shorthand. PVRTC2 in this press release refers to the second generation of PVRTC technology. The recommended shorthand for the variants is PVRTC 2bpp, PVRTC 4bpp, PVRTC2 2bpp and PVRTC2 4bpp.
PVRTC Reference Documents
Fenney, S. (2003) 'Texture Compression Using Low-Frequency Signal Modulation'. In HWWS ’03: Proceedings of the ACM SIGGRAPH/EUROGRAPHICS conference on Graphics hardware, pages 84–91, 2003.
About Imagination Technologies
Imagination Technologies Group plc (LSE:IMG) – a global leader in multimedia and communication technologies – creates and licenses market-leading multimedia IP cores for graphics, video, and display processing, multi-threaded embedded processing/DSP cores and multi-standard communications and connectivity processors. These silicon intellectual property (IP) solutions for systems-on-chip (SoC) are complemented by platform level IP and services, a strong array of software tools and drivers and extensive developer and middleware ecosystems. Target markets includemobile phone, handheld multimedia, home consumer entertainment, mobile and low-power computing, and in-car electronics.Its licensees include many of the leading semiconductor and consumer electronics companies. Imagination has corporate headquarters in the United Kingdom, with sales and R&D offices worldwide. See: www.imgtec.com.