Date: 27/01/2009

Whitepaper on improving HDTV picture quality by preserving chroma integrity

Fujitsu Computer Products of America has published a whitepaper entitled “The Cure for Concatenation: Preserving 4:2:0 Chroma Integrity in Concatenated Operations.” The paper examines the impact of 4:2:0 chroma dedgradation on high-definition (HD) picture quality within concatenated broadcasting infrastructures, and outlines how Fujitsu’s innovative Perfect Reconstruction Filter technology—to be integrated into the Fujitsu IP-9500e MPEG-4 AVC encoder this year—helps HDTV broadcasters preserve chroma integrity. The whitepaper is available for download at http://www.fujitsu.com/us/services/computing/peripherals/video/support/whitepapers.html

“The IP-9500 continues to set the industry standard when it comes to HD picture quality and low latency, and Fujitsu is constantly investigating new challenges facing the industry so we can improve the IP-9500’s rich feature set to provide our customers with a distinct competitive advantage,” said Vic Herring, senior director, video solutions group, Fujitsu Computer Products of America, Inc. “For example, our Perfect Reconstruction Filter process effectively migitages the inherrent degradation of chroma components caused by concatenation in the multiple encode-decode process, enabling HDTV broadcasters to cost-effectively deliver a picture quality that simply cannot be achived without this breakthrough technology.”

The whitepaper illustrates the advantages of encoding content using 4:2:0 chroma sampling instead of 4:2:2, including how it requires about 20 percent less bandwidth while yielding the same picture quality. The paper also examines how the chroma component will suffer loss of resolution during each concatenated operation within conventional encoder and decoder design. The up-sampling and down-sampling of the 4:2:0 stream—required at each digital turn-around of the signal delivery process—can result in visual blurring of the color image, severely compromising the quality and integrity of the feed that is required for HD compression.

The Fujitsu Perfect Reconstruction Filter, developed by Dr. Akira Nakagawa and a team of engineers at Fujitsu Laboratories in Japan, addresses these challenges and enables broadcasters to utilize 4:2:0 chroma sampling without concerns of degradation. In field tests, up to 16 encode/decode concatenations were performed to compare results of the Fujitsu filter technology with conventional MPEG-4 encoders and decoders. As highlighted in the whitepaper, the results of this and other tests demonstrate that feeds using the Perfect Reconstruction Filter set at each concatenation maintained their integrity and picture quality as compared with signals sent over an infrastructure that did not include the Fujitsu technology.