Broadcast Engineering - April 2008 - (Page 19)

TECHNOLOGY IN ACTION BEYOND THE HEADLINES ﬁelds do not give coherent information. However, this improvement is at the core of nearly all motion adaptive deinterlacing procedures used by the television industry. Motion compensated deinterlacing Motion adaptive techniques are not sophisticated enough when sharp image structures move. The industry and image processing research community largely viewed motion compensation as the next-generation technology. The idea is to ﬁrst compute the motion of each pixel and then, for missing pixels, to perform the interpolation in time in a direction that follows the time displacements. The interpolation is thus performed in a time direction that compensates for the motion. Developing a robust motion compensation deinterlacing technology has been the Holy Grail of the video conversion industry during the last 10 years. Yet after all this time and effort, it could be argued that no motion compensation algorithm product is available that meets the expected performance and cost levels, particularly when compared with motion adaptive techniques. Motion compensation is based on the assumptions that a single motion can be associated to each image pixel, and that this motion, also called optical ﬂow, can be computed reliably. Optical ﬂow research has shown that these unicity and robustness assumptions are incorrect. First, one cannot always associate a single motion to a pixel (transparencies). Second, optical ﬂow estimation is intrinsically unreliable and is known as an ill-posed problem. It does not mean that motion can never be measured accurately, but rather that it cannot always be measured accurately. As a consequence, motion compensation algorithms measure the reliability of their motion calculation and when not sufﬁciently reliable, a spatial interpolation is performed. Obtaining robust results requires being conservative and hence performing many spatial interpolations. It thus often leads to the same type of artifacts as motion adaptive algorithms, with many more operations and associated high cost. Super-Resolution Bandlet Technology with total variation Motion adaptive algorithms have a limited performance because a missing pixel is computed from a small set of available pixels. Motion compensated algorithms have the advantage of using information in a full threedimensional space-time neighbourhood but are less robust because of Your timeline is just a keystroke away Improve your HD post production workflow with new bi-directional transfer capabilities from EVS and Avid. Live feeds streaming and clip transfer between EVS’ reliable XT[2] production server and Avid’s stateof-the-art post production tools are now just a keystroke away. Thanks to the XT[2]’s native support of the SMPTE VC-3 compliant codec and Avid DNxHD®, no transcoding is required, giving you instant access to media and metadata. EVS brings your timeline closer to live Instantly. B visit us at N A Booth C4911 Instant Tapeless Production www.evs.tv Post Production Instant tapeless technology BELGIUM l CHINA l FRANCE l HONG KONG l ITALY l SPAIN l UAE l UNITED KINGDOM l USA EVS Broadcast Equipment / Sales & Marketing Phone : +32 4 361 7000 - Fax : +32 4 361 7099 - E-mail : sales@evs.tv April 2008 | broadcastengineeringworld.com 19 http://www.evs.tv http://www.evs.tv http://www.broadcastengineeringworld.com

Table of Contents Feed for the Digital Edition of Broadcast Engineering - April 2008

Broadcast Engineering - April 2008 Contents Editorial HD Newsrooms Wavelet Compression Mobile TV Audio Processing for HDTV, Part 1 QoE for IPTV End Users NAB Update Asset Management Advertisers Index

Broadcast Engineering - April 2008

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