Imperial College London
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ProfessorPier LuigiDragotti

Faculty of Engineering, Department of Electrical and Electronic Engineering

Professor of Signal Processing
 
 
 
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Contact

 

+44 (0)20 7594 6192p.dragotti

 
 
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Location

 

814Electrical EngineeringSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
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255 results found

Zhang Y, 2014, The modulated E-spline with multiple subbands and its application to sampling wavelet-sparse signals

Conference paper

Wei X, Dragotti PL, 2014, UNIVERSAL SAMPLING OF SIGNALS WITH FINITE RATE OF INNOVATION, 2014 IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

Recently it has been shown that specific classes of nonbandlimited signals known as signals with finite rate of innovation (FRI) can be perfectly reconstructed by using appropriate sampling kernels and reconstruction schemes. This exact FRI framework was later extended to an approximate FRI framework that works with any kernel.Reconstruction is achieved by recovering all the parameters in the parametric model of the incoming signal, hence it is essential to know the model order (the rate of innovation) to ensure recovery. In view of this, we devise an algorithm for identifying the rate of innovation in order to extend the current sampling scheme to a universal one which enables sampling signals with arbitrary FRI using any acquisition device. Our proposed algorithm can effectively identify the rate of innovation prior to the signal reconstruction using arbitrary kernels and in different noise levels where we also show that it achieves the performance predicted by the Cramer-Rao bounds.

Conference paper

Scholefield A, Dragotti PL, 2014, Quadtree Structured Image Approximation for Denoising and Interpolation, IEEE TRANSACTIONS ON IMAGE PROCESSING, Vol: 23, Pages: 1226-1239, ISSN: 1057-7149

Journal article

Gilliam C, Dragotti P-L, Brookes M, 2014, On the Spectrum of the Plenoptic Function, IEEE TRANSACTIONS ON IMAGE PROCESSING, Vol: 23, Pages: 502-516, ISSN: 1057-7149

Journal article

Pan H, Blu T, Dragotti PL, 2014, Sampling curves with finite rate of innovation, IEEE Transactions on Signal Processing, Vol: 62, Pages: 458-471, ISSN: 1053-587X

In this paper, we extend the theory of sampling signals with finite rate of innovation (FRI) to a specific class of two-dimensional curves, which are defined implicitly as the zeros of a mask function. Here the mask function has a parametric representation as a weighted summation of a finite number of complex exponentials, and therefore, has finite rate of innovation . An associated edge image, which is discontinuous on the predefined parametric curve, is proved to satisfy a set of linear annihilation equations. We show that it is possible to reconstruct the parameters of the curve (i.e., to detect the exact edge positions in the continuous domain) based on the annihilation equations. Robust reconstruction algorithms are also developed to cope with scenarios with model mismatch. Moreover, the annihilation equations that characterize the curve are linear constraints that can be easily exploited in optimization problems for further image processing (e.g., image up-sampling). We demonstrate one potential application of the annihilation algorithm with examples in edge-preserving interpolation. Experimental results with both synthetic curves as well as edges of natural images clearly show the effectiveness of the annihilation constraint in preserving sharp edges, and improving SNRs.

Journal article

Nativia JO, Lu YM, Dragotti PL, 2014, FINITE DIMENSIONAL FRI, IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Publisher: IEEE, ISSN: 1520-6149

Conference paper

Jones Z, Brookes M, Dragotti PL, Benton Det al., 2014, WIDE-BASELINE IMAGE CHANGE DETECTION, IEEE International Conference on Image Processing (ICIP), Publisher: IEEE, Pages: 1589-1593, ISSN: 1522-4880

Conference paper

Pearson J, Visentini-Scarzanella M, Brookes M, Dragotti PLet al., 2014, TILTED LAYER-BASED MODELING FOR ENHANCED LIGHT-FIELD PROCESSING AND IMAGE BASED RENDERING, IEEE International Conference on Image Processing (ICIP), Publisher: IEEE, Pages: 1917-1921, ISSN: 1522-4880

Conference paper

Thongkamwitoon T, Muammar H, Dragotti PL, 2014, ROBUST IMAGE RECAPTURE DETECTION USING A K-SVD LEARNING APPROACH TO TRAIN DICTIONARIES OF EDGE PROFILES, IEEE International Conference on Image Processing (ICIP), Publisher: IEEE, Pages: 5317-5321, ISSN: 1522-4880

Conference paper

Kotzagiannidis MS, Dragotti PL, 2014, SPARSE GRAPH SIGNAL RECONSTRUCTION AND IMAGE PROCESSING ON CIRCULANT GRAPHS, IEEE Global Conference on Signal and Information Processing (GlobalSIP), Publisher: IEEE, Pages: 923-927

Conference paper

Murray-Bruce J, Dragotti PL, 2014, SPATIO-TEMPORAL SAMPLING AND RECONSTRUCTION OF DIFFUSION FIELDS INDUCED BY POINT SOURCES, IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Publisher: IEEE, ISSN: 1520-6149

Conference paper

Urigueen JA, Blu T, Dragotti PL, 2013, FRI Sampling With Arbitrary Kernels, IEEE TRANSACTIONS ON SIGNAL PROCESSING, Vol: 61, Pages: 5310-5323, ISSN: 1053-587X

Journal article

Pearson J, Brookes M, Dragotti P-L, 2013, Plenoptic layer-based modelling for image based rendering, IEEE Transactions on Image Processing, Vol: 22, Pages: 3405-3419, ISSN: 1057-7149

Journal article

Oñativia J, Schultz S, Dragotti PL, 2013, A finite rate of innovation algorithm for fast and accurate spike detection from two-photon calcium imaging, Journal of Neural Engineering, Vol: 10

Journal article

Dragotti PL, Onativia J, Urigueen JA, Blu Tet al., 2013, Approximate Strang-Fix: Sampling Infinite Streams of Diracs with any Kernel, Conference on Wavelets and Sparsity XV, Publisher: SPIE-INT SOC OPTICAL ENGINEERING, ISSN: 0277-786X

Conference paper

Visentini-Scarzanella M, Tagliasacchi M, Dragotti PL, 2013, Quantisation Invariants for Transform Parameter Estimation in Coding Chains, Data Compression Conference (DCC), Publisher: IEEE, Pages: 281-290, ISSN: 1068-0314

Conference paper

Thongkamwitoon T, Muammar H, Dragotti PL, 2013, REVERSE ENGINEERING OF SIGNAL ACQUISITION CHAINS USING THE THEORY OF SAMPLING SIGNALS WITH FINITE RATE OF INNOVATION, IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP), Publisher: IEEE, Pages: 5910-5914, ISSN: 1520-6149

Conference paper

Onativia J, Urigueen JA, Dragotti PL, 2013, SEQUENTIAL LOCAL FRI SAMPLING OF INFINITE STREAMS OF DIRACS, IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP), Publisher: IEEE, Pages: 5440-5444, ISSN: 1520-6149

Conference paper

Muammar H, Dragotti PL, 2013, AN INVESTIGATION INTO ALIASING IN IMAGES RECAPTURED FROM AN LCD MONITOR USING A DIGITAL CAMERA, IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP), Publisher: IEEE, Pages: 2242-2246, ISSN: 1520-6149

Conference paper

Bestagini P, Visentini-Scarzanella M, Tagliasacchi M, Dragotti PL, Tubaro Set al., 2013, VIDEO RECAPTURE DETECTION BASED ON GHOSTING ARTIFACT ANALYSIS, 20th IEEE International Conference on Image Processing (ICIP), Publisher: IEEE, Pages: 4457-4461, ISSN: 1522-4880

Conference paper

Tagliasacchi M, Visentini-Scarzanella M, Dragotti PL, Tubaro Set al., 2013, TRANSFORM CODER IDENTIFICATION WITH DOUBLE QUANTIZED DATA, 20th IEEE International Conference on Image Processing (ICIP), Publisher: IEEE, Pages: 1660-1664, ISSN: 1522-4880

Conference paper

Visentini-Scarzanella M, Dragotti PL, 2013, Modelling Radial Distortion Chains for Video Recapture Detection, 15th IEEE International Workshop on Multimedia Signal Processing (MMSP), Publisher: IEEE, Pages: 412-417, ISSN: 2163-3517

Conference paper

Tagliasacchi M, Visentini-Scarzanella M, Dragotti PL, Tubaro Set al., 2013, TRANSFORM CODER IDENTIFICATION, IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP), Publisher: IEEE, Pages: 5785-5789, ISSN: 1520-6149

Conference paper

Gelman A, Berent J, Dragotti PL, 2012, Layer-based sparse representation of multiview images, EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING, Pages: 1-15, ISSN: 1687-6180

This article presents a novel method to obtain a sparse representation of multiview images. The method is based on the fact that multiview data is composed of epipolar-plane image lines which are highly redundant. We extend this principle to obtain the layer-based representation, which partitions a multiview image dataset into redundant regions (which we call layers) each related to a constant depth in the observed scene. The layers are extracted using a general segmentation framework which takes into account the camera setup and occlusion constraints. To obtain a sparse representation, the extracted layers are further decomposed using a multidimensional discrete wavelet transform (DWT), first across the view domain followed by a two-dimensional (2D) DWT applied to the image dimensions. We modify the viewpoint DWT to take into account occlusions and scene depth variations. Simulation results based on nonlinear approximation show that the sparsity of our representation is superior to the multi-dimensional DWT without disparity compensation. In addition we demonstrate that the constant depth model of the representation can be used to synthesise novel viewpoints for immersive viewing applications and also de-noise multiview images.

Journal article

Thongkamwitoon T, Muammar H, Dragotti PL, 2012, IDENTIFICATION OF IMAGE ACQUISITION CHAINS USING A DICTIONARY OF EDGE PROFILES, 20th European Signal Processing Conference (EUSIPCO), Publisher: IEEE COMPUTER SOC, Pages: 1757-1761, ISSN: 2076-1465

Conference paper

Hirabayashi A, Dragotti P-L, 2012, LINE-EDGE EXTRACTION BASED ON E-SPLINE ACQUISITION MODEL AND A FAST OPTIMIZATION ALGORITHM, 19th IEEE International Conference on Image Processing (ICIP), Publisher: IEEE, Pages: 89-92, ISSN: 1522-4880

Conference paper

Gilliam C, Pearson J, Brookes M, Dragotti PLet al., 2012, IMAGE BASED RENDERING WITH DEPTH CAMERAS: HOW MANY ARE NEEDED?, IEEE International Conference on Acoustics, Speech and Signal Processing, Publisher: IEEE, Pages: 5437-5440, ISSN: 1520-6149

Conference paper

Visentini-Scarzanella M, Dragotti PL, 2012, Video Jitter Analysis for Automatic Bootleg Detection, 14th IEEE International Workshop on Multimedia Signal Processing (MMSP), Publisher: IEEE, Pages: 101-106, ISSN: 2163-3517

Conference paper

Caballero J, Urigueen JA, Schultz SR, Dragotti PLet al., 2012, SPIKE SORTING AT SUB-NYQUIST RATES, IEEE International Conference on Acoustics, Speech and Signal Processing, Publisher: IEEE, Pages: 585-588, ISSN: 1520-6149

Conference paper

Gelman A, Dragotti PL, Velisavlievic V, 2012, Multi-view Image Coding using Depth Layersand an Optimized Bit Allocation, IEEE Transactions on Image Processing

Journal article

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