MARCH 1--Amphion Semiconductor Ltd. (San Jose, CA; www.amphion.com) claims to have developed the first entirely hardware-accelerated wavelet-transform-based JPEG2000 encoder core for advanced still and motion image-compression applications, such as 'dual-mode' still/movie-clip multimegapixel digital cameras, medical imaging, and surveillance. The Amphion CS6510 JPEG2000 hardware-accelerator core interfaces with any embedded host processor to construct a complete JPEG2000 encoding system on a single chip.
The CS6510 core is fully compliant with the ISO/IEC 15444-1 standard JPEG2000 image-coding system and carries out computationally intensive tasks such as wavelet transform, entropy coding, quantization, and data scheduling. It allows the system processor to handle simple tasks such as managing the user interface and output data formatting. When implemented in 180-nm CMOS process technology, the CS6510 delivers data encoding rates up to 60 MS/s on 8-bit samples with real-time `lossy' image-compression ratios up to 50:1. The core also handles arbitrary image sizes, standard `lossless' compression, flexible image input formats, and a variety of grayscale and color-imaging formats such as RGB, YUV, YCrCb, and CMYK.
Amphion can configure the performance and power consumption of the reference CS6510 JPEG2000 core to cover a variety of applications. For example, for medical-imaging applications where real-time high-resolution images are vital, the performance can be boosted to 480 Mbits/s.
"The CS6510 off-loads computationally intensive JPEG2000 algorithms from the embedded system processor," explains John McCanny, Amphion chief technology officer. "In dual-mode digital cameras, for instance, that enables the processor to take on other value-add functionality in the system. Hardware-accelerated compression is also necessary to take full advantage of the new high-color resolution, 16-Mpixel CMOS image sensors entering the market."
The reference Amphion JPEG2000 encoder core balances between high-quality compression and low-power consumption with sustained data rates greater than 100 Mbits/s, enabling the compression of full-motion, full-color video images at frame sizes in excess of standard-definition TV (720 x 480 pixels). This makes the CS6510 a candidate for dual-mode still/video digital cameras and for surveillance systems.
"Amphion's encoder core has successfully overcome the memory management issue in wavelet-transform blocks. That's one of the main challenges in JPEG2000 implementation," remarks Stephen Farson, Amphion vice president of engineering. "Most of the power consumption occurs in memory management of wavelet-transform data. Amphion's line-based implementation performs complex wavelet-transform algorithms using 5/3 and 9/7 filters for real-time lossy and lossless compression of JPEG2000 Profile-0 with minimal memory usage. The result is an overall decrease in power consumption."
JPEG2000 is the new wavelet-based, digital imaging-compression standard and is the successor to the widely used JPEG standard. It's a flexible and elegant coding system that permits users to store more images in less memory. JPEG can only best support compression ratios up to 25:1. JPEG2000 also enables users to control image quality without reprocessing. For example, digital images can be downloaded with low quality first, and then the quality and resolution of a selected image can improve progressively without reprocessing.
The JPEG2000 standard offers enhanced compression and features superior to the original JPEG standard, such as improved compression performance, improved image quality, especially at compression ratios above 25:1; higher resolution without noise and blocking artifacts, even at high compression; resolution and quality scalability to deliver compressed images at a variety of resolution and quality levels from lossy to lossless in the same file; real-time lossy and lossless compression--vital in applications such as medical imaging--JPEG cannot support both at the same time; superior rate control to supply higher image quality for a prespecified file size; and error resilience--essential for transmission of images in noisy environments.
For more information about the JPEG2000 and JPEG standards, visit www.jpeg.org.