Parallax-Based View Synthesis From Uncalibrated Images

In this paper we present an image-based system for novel view synthesis from multiple model views. Our method works by segmenting images of a static scene in background and foreground, basing on motion parallax. From this segmentation we are able to recover the relative affine structure. Finally, we synthesize novel views with an original method based on step-wise replication of the epipolar geometry acquired from few model or "seed" views. The method is uncalibrated, for it does not need the rigid displacements in the Euclidean frame (which is unknown), and it is automatic, for it does not require the user to manually specify viewing parameters.

View Synthesis from Uncalibrated Images Using Parallax

This work deals with the view synthesis problem, i.e., how to generate snapshots of a scene taken from a "virtual " viewpoint different from all the viewpoints of the real views. Starting from uncalibrated reference images, the geometry of the scene is recovered by means of the relative affine structure. This information is used to extrapolate novel views using planar warping plus parallax correction. The contributions of this paper are twofold. First we introduce an automatic method for specifying the virtual viewpoint based on the replication of the epipolar geometry linking two reference views. Second, we presents a method for generating synthetic views of a soccer ground starting from a single uncalibrated image. Experimental results using real images are shown

Mutations of Cystic Fibrosis Transmembrane Conductance Regulator Gene Cause a Monocyte-Selective Adhesion Deficiency

Rationale: Cystic fibrosis (CF) is a common genetic disease caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Persistent lung inflammation, characterized by increasing polymorphonuclear leukocyte recruitment, is a major cause of the decline in respiratory function in patients with CF and is a leading cause of morbidity and mortality. CFTR is expressed in various cell types, including leukocytes, but its involvement in the regulation of leukocyte recruitment is unknown. Objectives: We evaluated whether CF leukocytes might present with alterations in cell adhesion and migration, a key process governing innate and acquired immune responses. Methods: We used ex vivo adhesion and chemotaxis assays, flow cytometry, immunofluorescence, and GTPase activity assays in this study. Measurements and Main Results: We found that chemoattractant-induced activation of β1 and β2 integrins and of chemotaxis is defective in mononuclear cells isolated from patients with CF. In contrast, polymorphonuclear leukocyte adhesion and chemotaxis were normal. The functionality of β1 and β2 integrins was restored by treatment of CF monocytes with the CFTR-correcting drugs VRT325 and VX809. Moreover, treatment of healthy monocytes with the CFTR inhibitor CFTR(inh)-172 blocked integrin activation by chemoattractants. In a murine model of lung inflammation, we found that integrin-independent migration of CF monocytes into the lung parenchyma was normal, whereas, in contrast, integrin-dependent transmigration into the alveolar space was impaired. Finally, signal transduction analysis showed that, in CF monocytes, chemoattractant-triggered activation of RhoA and CDC42 Rho small GTPases (controlling integrin activation and chemotaxis, respectively) was strongly deficient. Conclusions: Altogether, these data highlight the critical regulatory role of CFTR in integrin activation by chemoattractants in monocytes and identify CF as a new, cell type–selective leukocyte adhesion deficiency disease, providing new insights into CF pathogenesis