Industry’s first visually lossless image compression for GPUs

PVRIC4 enables random-access visually lossless image compression, ensuring bandwidth and memory footprint savings of at least 50%, and enabling systems to overcome performance bandwidth constraints.

Imagination provides PVRIC4 as a standalone IP block for SoC manufacturers to integrate into their multimedia pipelines. The block is already used by some of the company's partners, including Chips&Media who have access to PVRIC4 as part of a recent collaboration to deliver an optimum solution for a system leveraging a PowerVR GPU and WAVE5 video codec.

Commenting, Linley Gwennap, principal analyst of The Linley Group, said: “The PVRIC4 is a significant advancement for GPU compression technology. The increasing demands on memory bandwidth and footprint are a real concern for SoC manufacturers, so the ability to combine lossless and visually lossless compression delivers both cost and bandwidth savings.”

PVRIC4 features a dual-pipeline framebuffer compression engine. A new lossy pipeline, used only if the lossless pipeline does not achieve 50% compression, ensures that even difficult to compress ‘noisy’ images are compressed with the highest fidelity. A decision logic block determines which output should be used to guarantee the compression ratio, and due to highly tuned algorithms, the image quality change is imperceptible.

A hybrid solution, PVRIC4 offers SoC manufacturers the best of both approaches, with the highest fidelity ensuring bandwidth and frame buffer allocation savings on graphics and video content. This is all performed in hardware and achieved without any performance overhead.

PVRIC4’s bandwidth savings translate into better battery life for consumers and cost savings for system manufacturers, enabling more RAM and bandwidth to be freed for other uses, such as enabling simultaneous fast 5G downloads while the GPU is in use, or a reduction in the number of DRAM devices used in the system.

Nigel Leeder, executive vice president, PowerVR, Imagination, said: “With the increasing demands introduced by higher resolution 4K and 8K displays as well as the desire to reduce system costs, the need to minimise memory bandwidth is an ongoing priority for our customers. They require a solution that keeps costs and power down. By introducing visually lossless compression into our GPUs, we can now guarantee a reduction in memory bandwidth and usage.”