Content-based retrival to image databases by means of MPEG-7

Project Supervisor: Prof. Dr.-Ing. R.-R. Grigat
Coworker: Dipl.-Ing. Natalia Gavrilova
Running time: 04.2001 - 12.2003
Financing: Industry
Publications: here
References: MPEG-7, Contents-Based Retrival, CBIR (Content-Based Image Retrieval), Image Databases

Mpeg-7 is a current standard, which supports a contents-based search in graphic data banks. During the data base production characteristics are extracted from each picture and stored as descriptions as well as the pictures. For the search no more are then used the pictures themselves, but their descriptions. The Mpeg-7 standard specifies the form of such descriptions. In this project a search algorithm is developed, which regains similar pictures in photo and video collections due to the descriptions of picture in the Mpeg-7 format.

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Energy dissipation levers signal processor architectures for MPEG applications

Project Supervisor: Prof. Dr.-Ing. R.-R. Grigat
Coworker: Dipl.-Ing. R. M. Finke
Running time: since 5.1998
Financing: TUHH
Publications: here
References: Processor simulation, achievement models, Mpeg-4

In portable Multimediageraeten - e.g. UMTS Handy, Notebook, personnel DATA Assistant (PDA) - are zukueftig ever more efficient applications to be realized (TV Broadcast, Videotelefonie, etc.). But throughput-strong processors with low
capacity are needed, since the available energy is limited by weight restrictions. In this project methods and tools are investigated for the performance analysis and reduction on algorithmic level. In addition the physically measurable power absorption is abgebildetet on the implemented software (data, instructions and
control signals). Thus the search area for energetically more favorable implementations can be substantially limited.

The project is occupied with the following partial aspects:

  • Redundancy reduction: Arithmetic imbedding
  • Prevarication reduction: Nonlinear quantization (picture)
  • Avoidance of Implementierungsoverhead: Optimization of the memory accesses

 

 

16-fach superelevated difference picture from original and quantized picture. Estimated reduction of the relative dynamic power absorption approx.. 15%

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Error-Concealment for MPEG

Project Supervisor: Prof. Dr.-Ing. R.-R. Grigat
Coworker: Dipl.-Ing. M. L├╝dicke
Running time: 12.1996 - 12.2000
Financing: Industry
Publications: here
References: Error covering, Motion Estimation, Statistic procedures, Interpolation procedure, Mpeg-2, Mpeg-4

Within the range of the consumer electronics the desire for portable Multimediaendgeraeten increases lately steadily. The associated datentransfer over partly strongly rushed and unreliable channels can with approximately redundancy-free data, e.g. a MPEG data stream, despite an error protection by a channel encoding to remaining errors at the entrance of the source decoder leading. The variables length code (VLCs), used in MPEG data streams, cannot be decoded in the event of an error i.d.R. any longer clearly, from which clearly visible errors in the decoded picture sequence result. In the literature become procedures, which cover such errors, when "error designates Concealment Techniques". The decoded MPEG data streams keep a large portion of redundancy both local and temporal. In the context of this research project different procedures error of the Concealment were developed and examined, which are based on Bewegungsestimation, statistic procedures and interpolation procedures.

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Transformation from DV to MPEG -2

Project Supervisor: Prof. Dr.-Ing. R.-R. Grigat
Coworker: Dipl.-Ing. N. Gavrilova
Running time: 1.1999 - 12.1999
Financing: Industry
Publications: here
References: Transcoding, DV, MPEG-2, Artifacts, Image quality, Bit rate,Quantization With a digital video recorder the necessity exists to transcodieren the data streams from data processing to Mpeg-2. Numerous artifacts in the output picture develop, in particular due to a very low desired bit rate with MPEG. These artifacts and their causes are to be studied, so that by a meaningful selection of the MPEG-specific coding parameters as high an output image quality as possible is reached.

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Mpeg-4 demonstrator on the VLIW processor TriMedia

Project Supervisor: Prof. Dr.-Ing. R.-R. Grigat
Coworker: Dipl.-Ing. N. Gavrilova
Running time: 1.2000 - 12.2001
Financing: Industry
Publications: here
References: TriMedia, MPEG-4, TSSA

It acts in this project around the development of a Mpeg-4 of system for the demonstration of error Concealment and error Resilience Tools. The demonstrator system contains a Mpeg-4 Encoder and a decoder and simulates an incorrect channel. The system is implemented on the Multimediaprozessor TriMedia by means of the TSSA (TriMedia Streaming software Architecture), so that the simple reusability of the software modules is guaranteed.

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