1,720,989 research outputs found
Geometric texture transfer via local geometric descriptors
Get PDFGeometric Texture Transfer, aimed to add fine grained details to surfaces, can be seen as a realistic advanced geometry modelling technique. At this aim, we investigate and advocate the use of local geometric descriptors as alternative descriptors to the vertex coordinates for surface representation. In particular, we consider the Laplacian coordinates, the normal-controlled coordinates and the mean value encoding, which are well prone to facilitate the transfer of source geometric texture details onto a target surface while preserving the underlying global shape of the target surface. These representations, in general, encode the underlying geometry by describing relative position of a vertex with respect to its local neighborhood, with different levels of invariance to rigid transformations and uniform scaling. We formulate the geometric texture transfer task as a constrained variational nonlinear optimization model that combines an energy term on the shape-from-operator inverse model with constraints aimed to preserve the original underlying surface shape. In contrast to other existing methods, which rely on the strong assumptions of bijectivity, equivalency in local connectivity, and require massive tesselations, we simply map the geometric texture on the base surface, under the only assumption of boundary matching. The proposed geometric texture transfer optimization model is then efficiently solved by nonlinear least squares numerical methods. Experimental results show how the nonlinear texture transfer variational approach based on mean value coordinates overcomes the performance of other alternative descriptors
Linear PDE Osmotic Flow for 3D Surfaces
No full textWe present a proof-of-concept study demonstrating the application
of the linear osmotic flow to unstructured domains in R3, such
as irregular meshes. This study aims to extend the osmotic filter to surfaces,
thereby simplifying some geometry processing tasks, such as surface
inpainting and completion (cloning), that typically require costly
and complex algorithms. This will include two new challenges: the numerical
solution of the drift-diffusion osmotic model on meshes, and the
use of surface geometric descriptors, which play the role of reference
function for the osmotic flow
Fast and stable schemes for non-linear osmosis filtering
No full textWe consider a non-linear variant of the transport-diffusion osmosis model for solving a variety of imaging problems such as shadow/soft-light removal and compact data representation. The non-linear behaviour is encoded in terms of a general scalar diffusivity function with suitable properties, which allows to balance the diffusion intensity over different regions of the image while preventing smoothing artefacts. For the proposed model, conservation properties (average intensity and non-negativity) are proved and a variational interpretation is showed for specific choices of the diffusivity function. Upon suitable spatial discretisation, both an explicit and a semi-implicit iterative schemes are considered, for which convergence conditions and unconditional stability results are proved, respectively. To validate the proposed modelling and the computational speed of the numerical schemes considered, we report several results and comparisons with state-of-the-art methods, showing that artefact-free and computationally efficient results are obtained in comparison to standard linear and anisotropic osmosis models
Sviluppo vegetativo, produttività e qualità dei frutti di clementine ‘SRA 92’ e arancio ‘Washington navel’ allevati su diversi portinnesti
No full text
Evaluation of alternative splicing in the Citrus sinensis glutathione S transferase gene family
No full textIdentification of differentially expressed genes in the flesh of blood and common oranges
No full textThe objective of this research was the identification
of genes differentially expressed in blood oranges
compared to common oranges and the identification of
anthocyanin pathway genes that are up-regulated in flesh of
blood oranges. A subtracted complementary DNA library
of 1,248 clones was constructed using RNA from the flesh
of a nucellar line (58-8D-1) of Moro (a blood orange) as
tester and from Cadenera (a common orange) as driver.
After screening by reverse Northern, a total of 230 clones
were found to be up-regulated in blood orange, while 30
were up-regulated in the common blond one. Sequence
analysis identified genes involved in the anthocyanin
pathway including genes encoding biosynthetic enzymes
like phenylalanine ammonialyase, chalcone synthase, dihydroflavonol-
4-reductase, anthocyanidin synthase, UDP:
glucose flavonoid 3-O-glucosyltransferase, glutathione
S-transferase, and a regulatory gene encoding a basic Helix-
Loop-Helix protein, while others were related to primary
metabolism, flavor biosynthesis, signal transduction mechanisms,
and defense. Some sequences were classified as
unknown and unnamed and some others were unclassified.
Semiquantitative reverse transcription-polymerase chain
reaction (PCR) and quantitative real-time PCR were used
to confirm the differential expression patterns of selected
candidate genes of different functional classes. Correlations
between the expression of some genes and the processes
involved in the ripening of blood oranges were identified
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