logo EDITE Marco CALEMME
Identité
Marco CALEMME
État académique
Thèse soutenue le 2016-09-20
Sujet: Codage de carte de profondeur par déformation de courbes élastiques
Direction de thèse:
Laboratoire:
Voisinage
Ellipse bleue: doctorant, ellipse jaune: docteur, rectangle vert: permanent, rectangle jaune: HDR. Trait vert: encadrant de thèse, trait bleu: directeur de thèse, pointillé: jury d'évaluation à mi-parcours ou jury de thèse.
Productions scientifiques
oai:hal.archives-ouvertes.fr:hal-01108222
Lossless contour coding using elastic curves in multiview video plus depth
International audience

Multi-view video plus depth is emerging as the most flexible format for 3D video representation, as witnessed by the current standardization efforts by ISO and ITU. In particular, in depth representation, arguably the most important information lies in object contours. As a consequence, an interesting approach consists in performing a lossless coding of object contours, possibly followed by a lossy coding of per-object depth values.

In this context, we propose a new technique for lossless coding of object contours, based on the elastic deformation of curves. Using the square-root velocity representation for the elements of the space of curves, we can model a continuous evolution of elastic deformations between two reference contour curves. An elastically deformed version of the reference contours can be sent to the decoder with a reduced coding cost and used as side information to improve the lossless coding of the actual contour.

Experimental results on several multiview video sequences show remarkable gains with respect to the reference techniques and to the state of the art.


EISSN: 2048-7703 APSIPA Transactions on Signal and Information Processing https://hal-institut-mines-telecom.archives-ouvertes.fr/hal-01108222 APSIPA Transactions on Signal and Information Processing, Cambridge University Press, 2014, pp.1-10. <10.1017/ATSIP.2014.20>ARRAY(0x7f0400b15a28) ARRAY(0x7f0400b16e10)
oai:hal.archives-ouvertes.fr:hal-01423653
Depth coding and perceived quality for 3D video
International audience
Multi-view video plus depth is emerging as the most flexible format for 3D video representation, as witnessed by the current standardization efforts by ISO and ITU. The depth information allows synthesizing virtual view points, and for its compression various techniques have been proposed. We make a preliminary investigation of the effects on the synthesized views of two different approaches: object-based and block-based, from a perceptual point of view.
Quality of Multimedia Experience (QoMEX), 2015 Seventh International Workshop on QoMEX 2015 https://hal.archives-ouvertes.fr/hal-01423653 QoMEX 2015, May 2015, Costa Navarino, Greece. Quality of Multimedia Experience (QoMEX), 2015 Seventh International Workshop on, pp.1 - 2, 2016, <10.1109/QoMEX.2015.7148116>ARRAY(0x7f03ffd2b7f8) 2015-05-26
oai:hal.archives-ouvertes.fr:hal-01423657
Depth map coding with elastic contours and 3D surface prediction
International audience
Depth maps are typically made of smooth regions separated by sharp edges. Following this rationale, this paper presents a novel coding scheme where the depth data is represented by a set of contours defining the various regions together with a compact representation of the values inside each region. A novel coding scheme based on elastic curves allows to compactly represent the contours exploiting also the temporal consistency in different frames. A 3D surface prediction algorithm is then exploited in order to obtain an accurate estimation of the depth field from the contours and a subsampled version of the data. Finally, an ad-hoc coding strategy for the low resolution data and the prediction residuals is presented. Experimental results prove how the proposed approach is able to obtain a very high coding efficiency outperforming the HEVC coder at medium-low bitrates.
Image Processing (ICIP), 2016 IEEE International Conference on ICIP 2016 https://hal.archives-ouvertes.fr/hal-01423657 ICIP 2016, Sep 2016, Phoenix, United States. Image Processing (ICIP), 2016 IEEE International Conference on, pp.1106 - 1110, 2016, <10.1109/ICIP.2016.7532529>ARRAY(0x7f040022ece8) 2016-09-25
oai:hal.archives-ouvertes.fr:hal-01423655
Contour-Based Depth Coding: A Subjective Quality Assessment Study
International audience
Multi-view video plus depth is emerging as the most flexible format for 3D video representation, as witnessed by the current standardization efforts by ISO and ITU. The depth information allows synthesizing virtual view points, and for its compression various techniques have been proposed. It is generally recognized that a high quality view rendering at the receiver side is possible only by preserving the contour information since distortions on edges during the encoding step would cause a sensible degradation on the synthesized view and on the 3D perception. As a consequence recent approaches include contour-based coding of depths. However, the impact of contour-preserving depth-coding on the perceived quality of synthesized images has not been conveniently studied. Therefore in this paper we make an investigation by means of a subjective study to better understand the limits and the potentialities of the different techniques. Our results show that the contour information is indeed relevant in the synthesis step: preserving the contours and coding coarsely the rest typically leads to images that users cannot tell apart from the reference ones, even at low bit rate. Moreover, our results show that objective metrics that are commonly used to evaluate synthesized images may have a low correlation coefficient with MOS rates and are in general not consistent across several techniques and contents.
Multimedia (ISM), 2015 IEEE International Symposium on IEEE International Symposium on multimedia (ISM 2015) https://hal.archives-ouvertes.fr/hal-01423655 IEEE International Symposium on multimedia (ISM 2015), Dec 2015, Miami, FL, United States. Multimedia (ISM), 2015 IEEE International Symposium on, pp.295 - 300, 2015, <10.1109/ISM.2015.34>ARRAY(0x7f0400b1b560) 2015-12-14
Soutenance
Thèse: "Codage de carte de profondeur par déformation de courbes élastiques"
Soutenance: 2016-09-20