Exercises / Laboratory work may also be assisted by Dr. Marco Dalai (marco.dalai@unibs.it)
EXTENDED PROGRAM
Introduction: Differences between a classical communication system and a multimedia communication system. Signal conversion/ Interlaced and Progressive Video. Digital (color) image formats. Digital Video formats. Digital audio formats: music/speech.
Multimedia information coding and representation principles: redundancy versus irrelevancy reductions (end-user, final device). Rate versus distortion.
Perceptual aspects: physiology of human visual system, psychovision, color perception and color representation. Auditory system.
Multidimensional spectrum: Multidimensional Fourier transform definition. Examples: Spectrum of a 2D sinusoid. Dirac wall. Multidimensional Fourier transform properties. Spectral transformation due to a reference system transformation. Shear reference system change; quincunx reference system change; scaling; hexagonal reference system change; rotation of the reference system. Graph Fourier Transform.
Sampling of multidimensional signals: Multidimensional Dirac train. Sampling on a cartesian grid: Sampled signal spectrum; no aliasing condition. Sampling of multidimensional signals on non cartesian grids: no aliasing condition. Sampling of images on a quincunx, hexagonal and shear grid. Sampling of progressive and interlaced video signals; shear sampling occurring in moving object tracking...
Multidimensional discrete space filtering: FIR/IIR filtering. Multidimensional transfer function. Multidimensional Z transform: Definition, Region of convergence, Properties. Stability conditions for an IIR multidimensional filter.
Predictive methods: First order AR models. Autocorrelation and power spectral density of an AR process. Mono- and multidimensional models. AR models of high horderl linear prediction; optima predication, Wiener-Hopf (Separable and non separable cases). Motion-compensated prediction.
Transform coding: Linear block transforms: 1-D and multidimensional case. Karhunen-Loeve transform. DCT transform. Quantization and entropy coding. Zig-zag scanning.
Subband coding: LOT transform. Decimation/Interpolation formulas (time/frequency interpretations). 2-channel decomposition. Perfect reconstruction filterbank. 1-D versus multidimensional subband decompositions. Discrete wavelet transform representation. Subband coding principles. Zerotree and SPIHT coding approaches.
Vector quantization: Coding and decoding principle. Llyod Max Quantizer. TVQ and LVQ quantizers.
Fractal coding of signals. Contractive transform. Iterated Function Systems. Mosaic Theorem.
Model-based approaches: Contour-texture coding. Head and shoulder models. Facial animation coding. SNHC.
ISO/JPEG, ISO/MPEG and H.26x families.
Visual information description: Descriptors and Description schemes. SIFT features.