Perspective (geometry)

About: Perspective (geometry) is a research topic. Over the lifetime, 277 publications have been published within this topic receiving 5795 citations. The topic is also known as: perspective (geometry).

The (non)-projective properties of the Japanese counter-expectational intensifier yoppodo

Abstract: This paper investigates the projective and non-projective properties of the Japanese counter-expectational intensifier yoppodo . Yoppodo has some unique semantic and pragmatic characteristics that ordinary intensifiers do not. In adjectival environments, yoppodo must co-occur with an inferential evidential marker (modal) and infers a high degree via the evidence. It also conventionally implicates that the high degree is above a speaker's expectation. The interesting feature of yoppodo is that its relationship with an evidential marker is tied up in the issue of projectability. If yoppodo is embedded under an attitude predicate and there is an evidential modal in the embedded clause, then yoppodo's counter-expectational meaning is subject-oriented. However, if yoppodo is embedded under an attitude predicate and there is an evidential modal in the main clause, then yoppodo 's counter-expectational meaning is speaker-oriented. I argue that the projective property of yoppodo is different from both typical conventional implicatures (e.g., expressives, appositives; see Potts 2005, 2015; Tonhauser et al. 2013) and typical presuppositions, and I claim that it belongs to a new type of projective content, a "dependent projective content". This paper provides a new perspective for the theories and classification of projective content.

Perspective-three-point (p3p) by determining the support plane

Abstract: This paper presents a new approach to solve the classic perspective-three-point (P3P) problem. The basic conception behind is to determine the support plane, which is defined by the three control points. Computation of the plane normal is formulated as searching for the maximum likelihood on the Gaussian hemisphere by exploiting the geometric constraints of three known angles and length ratios from the control points. The distances of the control points are then computed from the normal and the calibration matrix by homography decomposition. The proposed algorithm has been tested with real image data. The computation errors for the plane normal and the distances are less than 0.35 degrees, and 0.8cm, respectively, within 1~2m camera-to-plane distances. The multiple solutions to P3P problem are also illustrated.

A novel algorithm for occlusions and perspective effects using a 3D object process

Abstract: In this paper, we introduce a novel probabilistic approach to handle occlusions and perspective effects. The proposed method is an object based method embedded in a marked point process framework. We apply it for the size estimation of a penguin colony, where we model a penguin colony as an unknown number of 3D objects. The main idea of the proposed approach is to sample some candidate configurations consisting of 3D objects lying in the real plane. A Gibbs energy is define on the configuration space. These configurations are projected onto the image plane to define the data term, to which some prior information is added. The configurations are modified until convergence using the multiple birth and death optimization algorithm and by measuring the similarity between the projected image of the configuration and the real image. During optimization, the proposed configuration is modeled by a mixed graph which represents all dependencies between the objects, including interaction between neighbor objects and parent-child dependency for occluded objects. We tested our model on synthetic image, and real images.

Comparison of geometric figures

Abstract: Although the geometric equality of figures has already been studied thoroughly, little work has been done about the comparison of unequal figures. We are used to compare only similar figures but would it be meaningful to compare non similar ones? In this paper we attempt to build a context where it is possible to compare even non similar figures. Adopting Klein's view for the Euclidean Geometry, we defined a relation "<=" as: S<=T whenever there is a rigid motion f so that f(S) is a subset of T. This relation is not an order because there are figures (subsets of the plane) so that S<=T, T<=S and S, T not geometrically equal. Our goal is to avoid this paradox and to track down non-trivial classes of figures where the relation "<=" becomes, at least, a partial order. Such a class will be called a good class of figures. A reasonable question is whether the figures forming a good class have certain properties and whether the algebra of these figures is also a good class. Therefore we classified the figures into those that cause the paradox mentioned above and those that never cause it. The last ones are called good figures. Although simple, the definition of the good figure was difficult to handle, therefore we introduced a more technical, but intrinsic and handy definition, that of the strongly good figure. With these tools we constructed a new context, where we expanded our perspective about the geometric comparison not only in the Euclidean but also in the Hyperbolic and in the Elliptic Geometry. Eventually, there are still some open and quite challenging issues, which we present them at the last part of the paper.