Cluster-Wise Ratio Tests for Fast Camera Localization

Feature point matching for camera localization suffers from scalability problems. Even when feature descriptors associated with 3D scene points are locally unique, as coverage grows, similar or repeated features become increasingly common. As a result, the standard distance ratio-test used to identify reliable image feature points is overly restrictive and rejects many good candidate matches. We propose a simple coarse-to-fine strategy that uses conservative approximations to robust local ratio-tests that can be computed efficiently using global approximate k-nearest neighbor search. We treat these forward matches as votes in camera pose space and use them to prioritize back-matching within candidate camera pose clusters, exploiting feature co-visibility captured by clustering the 3D model camera pose graph. This approach achieves state-of-the-art camera localization results on a variety of popular benchmarks, outperforming several methods that use more complicated data structures and that make more restrictive assumptions on camera pose. We also carry out diagnostic analyses on a difficult test dataset containing globally repetitive structure that suggest our approach successfully adapts to the challenges of large-scale image localization

Aplicaciones de los métodos criptográficos

Peer Reviewe

Televisión y Redes Sociales: nuevo paradigma en la promoción de contenidos televisivos

Una de las aplicaciones donde la industria televisiva encuentra un fructífero e inesperado punto de confluencia con Internet es en las redes sociales. Posibilitan la promoción de cualquier contenido, generando una vía de comunicación con gran capacidad de retroalimentación. Además se constituye como una herramienta de gran eficacia para establecer audiencias dinámicas interesadas en participar en sus contenidos televisivos. A través de las redes sociales, las cadenas pueden acceder a sus audiencias fuera del medio televisivo y, por tanto, permite superar gran parte de sus debilidades, como la fugacidad de sus mensajes o la imposibilidad de interactuación.One of the applications in which the television industry found a productive and unexpected point of convergence with the Internet is on the social media. Television uses the social networks as an information channel and especially to promote any type of media content, generating a very active channel of communication and with the capacity of obtaining feedback that serves as a window for all sorts of news. Through social networks, television channels can access their audiences outside of the television media and because of this, it allows to exceed a great part of their weaknesses, such as the fleetingness of their messages or impossibility of their interactions

El apolillado reino de la fantasía absoluta

La flor de lilolá. Luis Fernando Macias. Editorial del propio bolsillo, Medellín, 1986, 74 págs

Lifting GIS Maps into Strong Geometric Context for Scene Understanding

Contextual information can have a substantial impact on the performance of visual tasks such as semantic segmentation, object detection, and geometric estimation. Data stored in Geographic Information Systems (GIS) offers a rich source of contextual information that has been largely untapped by computer vision. We propose to leverage such information for scene understanding by combining GIS resources with large sets of unorganized photographs using Structure from Motion (SfM) techniques. We present a pipeline to quickly generate strong 3D geometric priors from 2D GIS data using SfM models aligned with minimal user input. Given an image resectioned against this model, we generate robust predictions of depth, surface normals, and semantic labels. We show that the precision of the predicted geometry is substantially more accurate other single-image depth estimation methods. We then demonstrate the utility of these contextual constraints for re-scoring pedestrian detections, and use these GIS contextual features alongside object detection score maps to improve a CRF-based semantic segmentation framework, boosting accuracy over baseline models

Aplicaciones de los métodos criptográficos

Peer Reviewe

(Ir)retroactividad de las modificaciones a la norma complementaria de una Ley Penal en Blanco

26 P.El autor, a partir del nullum crimen nulla poena sine lege, expone los alcances del principio de legalidad en las leyes penales en blanco, indicando que aquellas deben contener el verbo rector de la conducta y su faz subjetiva, permitiendo su complemento por las normas reglamentarias.Reconociendo a la seguridad jurídica como fundamento de la irretroactividad de la ley penal, y a la proporcionalidad y necesidad de la pena como justificación de la retroactividad de la ley penal más benigna, expone los problemas de aplicación retroactiva que pueden aparecer con la modificación de la norma complementaria. Palabras clave: Tipo penal en blanco, retroactividad,irretroactividad, norma complementaria, seguridad jurídica, proporcionalidad y necesidad de pena./ABSTRACT:The author, starting from the nullum crimen nulla poena sine lege principle, explains the scope of the legality principle for criminal laws in blank, stating that they must contain the main verb of the conduct and its subjective aspect, thus allowing their completion through statutory norms.Recognizing legal certainty as the basis for irretroactivity of criminal laws, and proportionality and necessity of punishment as a justification for more benign criminal law retroactivity, shows the underlying retroactive application problems of amending the statutory norm. Key words: In blank criminal type, retroactivity, irretroactivity, statutory norms, legal certainty, proportionality and necessity of punishmen

The invisibility of the Haitian Revolution and its possible decolonial resistances from the negritude

El presente artículo pretende analizar el silenciamiento de la Revolución de Haití por parte de las narrativas eurocéntricas y occidentales de la historia universal. En este sentido, es de vital importancia señalar que esta invisibilización es producto de una inferiorización epistémica y racial por parte del locus de enunciación eurocentrista, el cual ha tenido el privilegio de categorizar los acontecimientos históricos según su cercanía con el modelo presupuesto ideal de humanidad occidental. Por otro lado, se expone el concepto de negritud de Aimé Césaire y Franz Fanon, dos intelectuales que constituyen el pensamiento anticolonial de mediados del siglo XX. A partir de esta visión, se plantea que la negritud, como categoría política y epistémica, permite el germen discursivo y práctico para las resistencias decoloniales en el Caribe, emergiendo el robo de la palabra y la construcción de su propio derecho a la enunciación. Desde esta óptica, se indaga en los dispositivos de poder que actúan en la geopolítica del conocimiento en torno a la Revolución de Haití, pero proponiendo finalmente una inversión de ésta desde el hecho político de la heterodefinicionThis article seeks to analyze the silencing of the Haitian Revolution on the part of the eurocentric and western narratives in universal history. In this regard, it is of vital importance to note that this invisibility is the product of a traditional epistemic and racial inferior status on the part of the eurocentric locus of enunciation, which has had the privilege to categorize the historical events according to their closeness to the pre-course western ideal model of humanity. On the other hand, it exposes the concept of negritude of Aimé Césaire and Franz Fanon, two intellectuals that constitute the anti-colonial thinking of the mid-twentieth century. From this vision, it is suggested that negritude, as both political and epistemic category, allows the discursive and practical germ for the decolonial resistances in the Caribbean, emerging the theft of the word and the construction of your own right to the enunciation. From this perspective, it explores the power devices operating in the geopolitics of knowledge about the Haitian Revolution, but finally proposing a reversal of this from the political fact of the heterodefinicio