G. Calvagno

University of Padua

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Simone Milani

University of Padua

R. Rinaldo

University of Udine

G.A. Mian

University of Padua

Stefano Andriani

Arri (Germany)

Daniele Menon

University of Padua

Piergiorgio Sartor

Sony (Taiwan)

Oliver Erdler

Sony (Taiwan)

Francesco Michielin

University of Padua

A. Zenoni

University of Brescia

M. Benettoni

Istituto Nazionale di Fisica Nucleare, Sezione di Padova

Cooperative Institutions

University of Padua

Istituto Nazionale di Fisica Nucleare, Sezione di Padova

STMicroelectronics (Italy)

University of Brescia

Istituto Nazionale di Fisica Nucleare

STMicroelectronics (Switzerland)

Politecnico di Milano

Istituto Nazionale di Fisica Nucleare, Sezione di Pavia

Brescia University

University of Trento

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Object oriented coding using 3D motion estimation

European Signal Processing Conference (1998)

G. Calvagno Vinicius Nakad Orsatti R. Rinaldo Luciano Sbaiz

In this work, we apply 3D motion estimation to the problem of motion compensation for video coding. We model the video sequence as the perspective projection of a collection of rigid bodies which undergo a roto-translational motion. Motion compensation of the sequence frames can be performed once the shape of the objects and the motion parameters are determined. The motion equations of a rigid body can be formulated as a non linear dynamic system whose state is represented by the motion parameters and by the scaled depths of the object feature points. An extended Kalman filter is then used to estimate both the motion and the object shape parameters simultaneously. We found that the inclusion of the shape parameters in the estimation procedure is essential for reliable motion estimation. Our experiments show that the proposed approach gives the following advantages: the filter gives more reliable estimates in the presence of measurement noise in comparison with other motion estimators that separately compute motion and structure; the filter can effectively track abrupt motion changes; the structure imposed by the model implies that the reconstructed motion is very natural as opposed to more common block-based schemes; the parametrization of the model allows for a very efficient coding of motion information.

Quarter-pixel motion

Motion field

Structure from Motion

Linear motion

10.5281/zenodo.36749

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Citations (0)

An image coding scheme using block prediction of the pyramid subband decomposition

R. Rinaldo G. Calvagno

In this work, we propose a hybrid vector quantization scheme for general images that aims at exploiting similarities among detail signals in a multiresolution decomposition of the image. In a multiresolution decomposition, the image is decomposed into a set of subbands which are localized in scale, orientation and space. Our coding scheme consists of dividing each subimage of the multiresolution decomposition into square range blocks. The range blocks are matched against domain blocks chosen in the lower resolution subimage with the same orientation, and coded through a description of the map transforming the domain block into the range block. The pool of of domain blocks acts as a codebook for the range block, as in vector quantization, with the difference that the codebook is built from blocks inside the multiresolution decomposition. If the prediction procedure is not satisfactory with respect to a target quality, the block is coded using a geometric vector quantizer for Laplacian random variables.< >

Pyramid (geometry)

Multiresolution analysis

10.1109/icip.1994.413481

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Citations (8)

A multiresolution approach to spike detection in EEG

G. Calvagno Mario Ermani R. Rinaldo Flavio Sartoretto

A technique is proposed for the automatic detection of spikes in electroencephalograms (EEG). A multiresolution approach and a non-linear energy operator are exploited. The signal on each EEG channel is decomposed into three subbands using a non-decimated wavelet transform. Each subband is analyzed by using a non-linear energy operator, in order to detect peaks. A decision rule detects the presence of spikes in the EEG, relying upon the energy of the three subbands. The effectiveness of the proposed technique was confirmed by analyzing both test signals and EEG layouts.

Energy operator

SIGNAL (programming language)

Multiresolution analysis

Operator (biology)

10.1109/icassp.2000.860176

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Citations (36)

Luminance driven sparse representation based demosaicking

2022 IEEE International Conference on Image Processing (ICIP) (2014)

M. Rossi G. Calvagno

Typical consumer cameras sense at each pixel only one out of the three color components the representation of a color image requires. Then the missing components are estimated via a procedure referred to as demosaicking. The recent spread of sparse regularization approaches for signal reconstruction purposes has extended to demosaicking algorithms too. In this paper, starting from a sparse representation based demosaicking algorithm recently appeared in the literature, a new one is devised. The proposed algorithm effectively estimates the original luminance component from the acquired data and then uses it to guide the sparsity based reconstruction of the full-resolution image. This hybrid approach to demosaicking allows the new algorithm to outperform the past one and to compete with leading demosaicking algorithms, both in terms of PSNR measure and visual quality.

Demosaicing

Representation

10.1109/icip.2014.7025358

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Citations (3)

A distributed video coder based on the H.264/AVC standard

European Signal Processing Conference (2007)

Simone Milani G. Calvagno

One of the latest innovations in the world of multimedia technologies is the application of Distributed Source Coding (DSC) theory to the robust transmission of video sequences. However, these DSC-based video encoders are usually characterized by a lower compression gain with respect to their hybrid counterparts. In this work, we investigate achieving H.264-like high compression efficiency with a DSC-based approach without constraints on encoding complexity. In this way, highly non-stationary video data are modelled through coarse low-cost Motion Estimation, and this allows us to obtain a good compression efficiency together with a certain robustness to channel errors and losses. Experimental results show that in presence of losses the presented algorithm permits a better quality with respect to H.264/AVC.

Distributed source coding

Robustness

Scalable Video Coding

Context-adaptive variable-length coding

10.5281/zenodo.40341

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Citations (9)

Synthesis Filter Bank Optimization in 1D and 2D Separable Subband Coding

Springer eBooks (1999)

G. Calvagno M. Cantagallo G.A. Mian R. Rinaldo

Filter bank

Sub-band coding

10.1007/978-1-4471-0859-7_2

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A cognitive approach for effective coding and transmission of 3D video

Proceedings of the 30th ACM International Conference on Multimedia (2010)

Simone Milani G. Calvagno

Reliable delivery of 3D video contents to a wide set of users is expected to be the next big revolution in multimedia applications provided that it is possible to grant a certain level of Quality-of-Experience (QoE) to the end user.

10.1145/1873951.1874009

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Citations (13)

A regularization approach to demosaicking

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2007)

Daniele Menon G. Calvagno

Demosaicking is the process of reconstructing a full resolution color image from the sampled data acquired by a digital camera that apply a color filter array to a single sensor. In this paper, we propose a regularization approach to demosaicking, making use of some prior knowledge about natural color images, such as smoothness of each single color component and correlation between the different color channels. Initially, a quadratic strategy is considered and a general approach is reported. Then, an adaptive technique is analyzed, in order to improve the reconstruction near the edges and the discontinuities of the image. This is performed using a novel strategy that avoids computational demanding iterations. The proposed approach provides good performances and candidates itself for many applications.

Demosaicing

Regularization

Color filter array

10.1117/12.765446

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Citations (2)

A low-complexity packet classification algorithm for multiple description video streaming over IEEE802.11E networks

Simone Milani G. Calvagno Riccardo Bernardini R. Rinaldo

The robust transmission of video sequences over wireless LANs presents several challenging problems concerning the presence of packet losses, delays, and bandwidth limitations. Their effect on the visual quality of the sequence reconstructed by the end user can be mitigated by adopting a wireless architecture that is able to support different levels of quality-of-service (QoS), like the IEEE 802.11e standard, and by compressing the video sequence to be transmitted using a robust source coder, like a multiple description coding (MDC) scheme. This paper presents a MDC-based video streaming architecture that tries to adaptively optimize the performance of both solutions by assigning the RTP video packets produced by the MDC encoder to the different QoS classes of IEEE 802.11e. Simulation results show that the performance is significantly improved with respect to a non-adaptive solution.

Multiple description coding

10.1109/icip.2008.4712444

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Citations (7)

Multiple Description Distributed Video Coding Using Redundant Slices and Lossy Syndromes

IEEE Signal Processing Letters (2009)

Simone Milani G. Calvagno

During the last years, video coding designers have proposed robust coding approaches that combine Multiple Description Coding (MDC) schemes with Distributed Video Coding (DVC) principles. In this way, it is possible to obtain a better error resilience since the distortion drifting through the sequence is significantly mitigated by the DVC coding unit. The paper presents a Multiple Description Distributed Video Coder (MDDVC) that codes the input video signal generating a set of "lossy" syndromes for each pixel block and creates different descriptions multiplexing primary and redundant video packets. Experimental results show that at high loss probabilities the proposed solution improves the results of the original MDC approach.

Lossy compression

Multiple description coding

10.1109/lsp.2009.2031748

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Citations (17)