Research On Technologies Of Content Description Creation For Program Producing And Scheduling In DTV Front-Ends

Now with the development of information technology, digital technologies are being used by broadcast and television step by step in our country, digital audio and video(AV) are replacing analog AV as well. Besides the macroscopical description information of program is used in the program producing and scheduling, the creation and usage of AV's content description information are taking more important place in the research of digital television(DTV).There are two parts, which are difference in the granularity of information description. First is design and implementation of DTV Program Producing and Scheduling System Front-ends(PSSF) based on the macroscopical description information of video program. PSSF is constituted by three modules: program producing, scheduling and broadcast control. Second is the creation of video content description information based on the microcosmic description, it includes shot segmentation and key frame extraction.About the first part, the description, obtaining and storage of videos' macroscopical information are explained firstly, then a program combination method is presented for simplifying program making, channel categorizing and organizing rules are proposed for arranging programs more conveniently, and moreover an online program update method for pure data channels is introduced.The sencond part, since the segmentation method based on color histogram will take camera's or objects'move as gradual change, the decrease of image entropy is made out, it is because of the shot blend which makes the frames out of focus at the shot dissolve, and the entropy changing rules of the objects'or camera's move are summed up. Dissolve and move can be distinguished with the changing difference of image entropy. The test result with TRECVID test videos indicates the improved method can raise the exactness rate or reduce the inaccuracy rate or both.A cluster algorithm of automatic key frame extraction based on adaptive threshold is employed and mended for extracting shot's key frames. The global and semi-global edge histograms generated directly from the mpeg-7 EHD is used in ISODATA, and this makes the key frames got by above method represent the shot better. To resolve the problem of picking up too much key frames for the long shot using the former cluster algorithm, the adaptive parameters are used in cluster algorithm.