Geovanni Martinez

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For coding of videophone sequences at very low bit rates, model-based coding is investigated. In a model-based coder, the human face in the videophone sequence is described by a three-dimensional (3D) face model. At the beginning of the videophone sequence, the model has to be adapted automatically to the size, position and orientation of the real face(More)
For coding of videophone sequences at very low bit rates, model-based coding is investigated. In a model-based coder, the human face in the videophone sequence is described by a three-dimensional (3D) face model. At the beginning of the videophone sequence, the model has to be adapted automatically to the shape, position and orientation of the real face(More)
An algorithm for motion estimation of articulated 3D objects for object–based analysis–synthesis coding (OBASC) is presented. For motion estimation an articulated object is first decomposed automatically into flexibly connected object– components. Each rigid 3D object–component is assumed to be connected to the object by spherical joints. Then, the 3D(More)
An object–based analysis–synthesis coder for coding moving images at low data rates is investigated. The coder is based on the source model of articulated three–dimensional objects. This model describes the real objects by means of model objects defined by shape, motion and color parameters. The model objects may be articulated, i.e. they consist of several(More)
Three Maximum-Likelihood thresholding algorithms based on population mixture models are investigated and a criterion is introduced for automatic selection of the most suitable Maximum-Likelihood thresholding algorithm for extracting object from their background in an arbitrary still image. The most suitable algorithm is that whose population mixture model(More)