Academic literature on the topic 'Visual object'

<p>Robustness of object detection against hard samples, especially small objects, has long been a critical and difficult problem that hinders development of convolutional object detectors. To address this issue, we propose Progressive Refinement Network to reduce classification ambiguity for scale robust object detection. In PRN, several orders of residuals for the class prediction are regressed from upper level contexts and the residuals are progressively added to the basic prediction stage by stage, yielding multiple refinements. Supervision signal is imposed at each stage and an integration of all stages is performed to obtain the final score. By supervision retaining through the context aggregation procedure, PRN avoids over dependency on higher-level information and enables sufficient learning on the current scale level. The progressive residuals added for refinements adaptively reduce the ambiguity of the class prediction and the final integration of all stages can further stabilize the predicted distribution. PRN achieves 81.3% mAP on the PASCAL VOC 2007 dataset and 31.7% AP (15.6% APS) on MS COCO dataset, which demonstrates the effectiveness and efficiency of the proposed method and its promising capability on scale robustness.</p> <p>&nbsp;</p>

Previous studies have found that the recognition of familiar objects is dependent on the orientation of the object in the picture plane. Here the time taken to locate rotated objects in the periphery was examined. Eye movements were also recorded. In all experiments, familiar objects were arranged in a clock face display. In experiment 1, subjects were instructed to locate a match to a central, upright object from amongst a set of randomly rotated objects. The target object was rotated in the frontoparallel plane. Search performance was dependent on rotation, yielding the classic ‘M’ function found in recognition tasks. When matching a single object in periphery, match times were dependent on the angular deviations between the central and target objects and showed no advantage for the upright (experiment 2). In experiment 3 the central object was shown in either the upright rotation or rotated by 120° from the upright. The target object was similarly rotated given four different match conditions. Distractor objects were aligned with the target object. Search times were faster when the centre and target object were aligned and also when the centre object was rotated and the target was upright. Search times were slower when matching a central upright object to a rotated target object. These results suggest that in simple tasks matching is based on image characteristics. However, in complex search tasks a contribution from the object's representation is made which gives an advantage to the canonical, upright view in peripheral vision.

Are visual and verbal processing systems functionally independent? Two experiments (one using line drawings of common objects, the other using faces) explored the relationship between the number of syllables in an object's name (one or three) and the visual inspection of that object. The tasks were short-term recognition and visual search. Results indicated more fixations and longer gaze durations on objects having three-syllable names when the task encouraged a verbal encoding of the objects (i.e., recognition). No effects of syllable length on eye movements were found when implicit naming demands were minimal (i.e., visual search). These findings suggest that implicitly naming a pictorial object constrains the oculomotor inspection of that object, and that the visual and verbal encoding of an object are synchronized so that the faster process must wait for the slower to be completed before gaze shifts to another object. Both findings imply a tight coupling between visual and linguistic processing, and highlight the utility of an oculomotor methodology to understand this coupling.

Phenomena associated with ‘central visual persistences’ (CPs) are new to both medical and psychological literature. Five subjects have reported similar CPs: positive afterimages following brief fixation of high-contrast objects or drawings and eye closure. CPs duplicate shapes and colors of single objects, lasting for about 15 s. Unlike retinal afterimages, CPs do not move with the eyes but are stable in extrapersonal space during head or body rotations. CPs may reflect sustained neural activity in neurons of association cortex, which mediate object perception. A remarkable finding is that CPs can be moved in any direction by the (unseen) hand holding the original seen object. Moreover, a CP once formed will ‘jump’ into an extended hand and ‘stick’ in that hand as it moves about. The apparent size of a CP of a single object is determined by the size of the gap between finger and thumb, even when no object is touched. These CPs can be either magnified or minified via the grip of the extended hand. The felt orientation of the hand-held object will also determine the orientation of the CP seen in that hand. Thus, kinesthetic signals from hand and arm movements can determine perceived location, size, and orientation of CPs. A neural model based on physiological studies of premotor, temporal, parietal, and prefrontal cortices is proposed to account for these novel phenomena.

Visual prosthesis applying electrical stimulation to restore visual function for the blind has promising prospects. However, due to the low resolution, limited visual field, and the low dynamic range of the visual perception, huge loss of information occurred when presenting daily scenes. The ability of object recognition in real-life scenarios is severely restricted for prosthetic users. To overcome the limitations, optimizing the visual information in the simulated prosthetic vision has been the focus of research. This paper proposes two image processing strategies based on a salient object detection technique. The two processing strategies enable the prosthetic implants to focus on the object of interest and suppress the background clutter. Psychophysical experiments show that techniques such as foreground zooming with background clutter removal and foreground edge detection with background reduction have positive impacts on the task of object recognition in simulated prosthetic vision. By using edge detection and zooming technique, the two processing strategies significantly improve the recognition accuracy of objects. We can conclude that the visual prosthesis using our proposed strategy can assist the blind to improve their ability to recognize objects. The results will provide effective solutions for the further development of visual prosthesis.

Per als humans, el reconeixement d’objectes és un procés gairebé instantani, precís i extremadament adaptable. A més, tenim la capacitat innata d’aprendre classes d’objectes nous a partir d’uns pocs exemples. El cervell humà redueix la complexitat de les dades entrants filtrant part de la informació i processant només aquelles coses que ens capturen l’atenció. Això, barrejat amb la nostra predisposició biològica per respondre a determinades formes o colors, ens permet reconèixer en un simple cop d’ull les regions més importants o destacades d’una imatge. Aquest mecanisme es pot observar analitzant sobre quines parts de les imatges hi posa l’atenció; on es fixen els ulls quan se’ls mostra una imatge. La forma més precisa de registrar aquest comportament és fer un seguiment dels moviments oculars mentre es mostren imatges. L’estimació computacional de la salubritat té com a objectiu identificar fins a quin punt les regions o els objectes destaquen respecte als seus entorns per als observadors humans. Els mapes Saliency es poden utilitzar en una àmplia gamma d’aplicacions, inclosa la detecció d’objectes, la compressió d’imatges i vídeos i el seguiment visual. La majoria de les investigacions en aquest camp s’han centrat en estimar automàticament els mapes de salubritat donats una imatge d’entrada. En el seu lloc, en aquesta tesi, ens proposem incorporar mapes de salubritat en una canalització de reconeixement d’objectes: volem investigar si els mapes de salubritat poden millorar els resultats del reconeixement d’objectes.En aquesta tesi, identifiquem diversos problemes relacionats amb l’estimació de la salubritat visual. En primer lloc, fins a quin punt es pot aprofitar l’estimació de la salubritat per millorar la formació d’un model de reconeixement d’objectes quan es disposa de dades d’entrenament escasses. Per solucionar aquest problema, dissenyem una xarxa de classificació d’imatges que incorpori informació d’informació salarial com a entrada. Aquesta xarxa processa el mapa de saliència a través d’una branca de xarxa dedicada i utilitza les característiques resultants per modular les característiques visuals estàndard de baix a dalt de l’entrada d’imatge original. Ens referirem a aquesta tècnica com a classificació d’imatges modulades en salinitat (SMIC). En amplis experiments sobre conjunts de dades de referència estàndard per al reconeixement d’objectes de gra fi, demostrem que la nostra arquitectura proposada pot millorar significativament el rendiment, especialment en el conjunt de dades amb dades de formació escasses.A continuació, abordem l’inconvenient principal de la canonada anterior: SMIC requereix un algorisme de saliència explícit que s’ha de formar en un conjunt de dades de saliència. Per solucionar-ho, implementem un mecanisme d’al·lucinació que ens permet incorporar la branca d’estimació de la salubritat en una arquitectura de xarxa neuronal entrenada de punta a punta que només necessita la imatge RGB com a entrada. Un efecte secundari d’aquesta arquitectura és l’estimació de mapes de salubritat. En experiments, demostrem que aquesta arquitectura pot obtenir resultats similars en reconeixement d’objectes com SMIC, però sense el requisit de mapes de salubritat de la veritat del terreny per entrenar el sistema. Finalment, hem avaluat la precisió dels mapes de salubritat que es produeixen com a efecte secundari del reconeixement d’objectes. Amb aquest propòsit, fem servir un conjunt de conjunts de dades de referència per a l’avaluació de la validesa basats en experiments de seguiment dels ulls. Sorprenentment, els mapes de salubritat estimats són molt similars als mapes que es calculen a partir d’experiments de rastreig d’ulls humans. Els nostres resultats mostren que aquests mapes de salubritat poden obtenir resultats competitius en els mapes de salubritat de referència. En un conjunt de dades de saliència sintètica, aquest mètode fins i tot obté l’estat de l’art sense la necessitat d’haver vist mai una imatge de saliència real.
El reconocimiento de objetos para los seres humanos es un proceso instantáneo, preciso y extremadamente adaptable. Además, tenemos la capacidad innata de aprender nuevas categorias de objetos a partir de unos pocos ejemplos. El cerebro humano reduce la complejidad de los datos entrantes filtrando parte de la información y procesando las cosas que captan nuestra atención. Esto, combinado con nuestra predisposición biológica a responder a determinadas formas o colores, nos permite reconocer en una simple mirada las regiones más importantes o destacadas de una imagen. Este mecanismo se puede observar analizando en qué partes de las imágenes los sujetos ponen su atención; por ejemplo donde fijan sus ojos cuando se les muestra una imagen. La forma más precisa de registrar este comportamiento es rastrear los movimientos de los ojos mientras se muestran imágenes. La estimación computacional del ‘saliency’, tiene como objetivo diseñar algoritmos que, dada una imagen de entrada, estimen mapas de ‘saliency’. Estos mapas se pueden utilizar en una variada gama de aplicaciones, incluida la detección de objetos, la compresión de imágenes y videos y el seguimiento visual. La mayoría de la investigación en este campo se ha centrado en estimar automáticamente estos mapas de ‘saliency’, dada una imagen de entrada. En cambio, en esta tesis, nos propusimos incorporar la estimación de ‘saliency’ en un procedimiento de reconocimiento de objeto, puesto que, queremos investigar si los mapas de ‘saliency’ pueden mejorar los resultados de la tarea de reconocimiento de objetos. En esta tesis, identificamos varios problemas relacionados con la estimación del ‘saliency’ visual. Primero, pudimos determinar en qué medida se puede aprovechar la estimación del ‘saliency’ para mejorar el entrenamiento de un modelo de reconocimiento de objetos cuando se cuenta con escasos datos de entrenamiento. Para resolver este problema, diseñamos una red de clasificación de imágenes que incorpora información de ‘saliency’ como entrada. Esta red procesa el mapa de ‘saliency’ a través de una rama de red dedicada y utiliza las características resultantes para modular las características visuales estándar ascendentes de la entrada de la imagen original. Nos referiremos a esta técnica como clasificación de imágenes moduladas por prominencia (SMIC en inglés). En numerosos experimentos realizando sobre en conjuntos de datos de referencia estándar para el reconocimiento de objetos ‘fine-grained’, mostramos que nuestra arquitectura propuesta puede mejorar significativamente el rendimiento, especialmente en conjuntos de datos con datos con escasos datos de entrenamiento. Luego, abordamos el principal inconveniente del problema anterior: es decir, SMIC requiere explícitamente un algoritmo de ‘saliency’, el cual debe entrenarse en un conjunto de datos de ‘saliency’. Para resolver esto, implementamos un mecanismo de alucinación que nos permite incorporar la rama de estimación de ‘saliency’ en una arquitectura de red neuronal entrenada de extremo a extremo que solo necesita la imagen RGB como entrada. Un efecto secundario de esta arquitectura es la estimación de mapas de ‘saliency’. En varios experimentos, demostramos que esta arquitectura puede obtener resultados similares en el reconocimiento de objetos como SMIC pero sin el requisito de mapas de ‘saliency’ para entrenar el sistema. Finalmente, evaluamos la precisión de los mapas de ‘saliency’ que ocurren como efecto secundario del reconocimiento de objetos. Para ello, utilizamos un de conjuntos de datos de referencia para la evaluación de la prominencia basada en experimentos de seguimiento ocular. Sorprendentemente, los mapas de ‘saliency’ estimados son muy similares a los mapas que se calculan a partir de experimentos de seguimiento ocular humano. Nuestros resultados muestran que estos mapas de ‘saliency’ pueden obtener resultados competitivos en mapas de ‘saliency’ de referencia.
For humans, the recognition of objects is an almost instantaneous, precise and extremely adaptable process. Furthermore, we have the innate capability to learn new object classes from only few examples. The human brain lowers the complexity of the incoming data by filtering out part of the information and only processing those things that capture our attention. This, mixed with our biological predisposition to respond to certain shapes or colors, allows us to recognize in a simple glance the most important or salient regions from an image. This mechanism can be observed by analyzing on which parts of images subjects place attention; where they fix their eyes when an image is shown to them. The most accurate way to record this behavior is to track eye movements while displaying images. Computational saliency estimation aims to identify to what extent regions or objects stand out with respect to their surroundings to human observers. Saliency maps can be used in a wide range of applications including object detection, image and video compression, and visual tracking. The majority of research in the field has focused on automatically estimating saliency maps given an input image. Instead, in this thesis, we set out to incorporate saliency maps in an object recognition pipeline: we want to investigate whether saliency maps can improve object recognition results. In this thesis, we identify several problems related to visual saliency estimation. First, to what extent the estimation of saliency can be exploited to improve the training of an object recognition model when scarce training data is available. To solve this problem, we design an image classification network that incorporates saliency information as input. This network processes the saliency map through a dedicated network branch and uses the resulting characteristics to modulate the standard bottom-up visual characteristics of the original image input. We will refer to this technique as saliency-modulated image classification (SMIC). In extensive experiments on standard benchmark datasets for fine-grained object recognition, we show that our proposed architecture can significantly improve performance, especially on dataset with scarce training data. Next, we address the main drawback of the above pipeline: SMIC requires an explicit saliency algorithm that must be trained on a saliency dataset. To solve this, we implement a hallucination mechanism that allows us to incorporate the saliency estimation branch in an end-to-end trained neural network architecture that only needs the RGB image as an input. A side-effect of this architecture is the estimation of saliency maps. In experiments, we show that this architecture can obtain similar results on object recognition as SMIC but without the requirement of ground truth saliency maps to train the system. Finally, we evaluated the accuracy of the saliency maps that occur as a side-effect of object recognition. For this purpose, we use a set of benchmark datasets for saliency evaluation based on eye-tracking experiments. Surprisingly, the estimated saliency maps are very similar to the maps that are computed from human eye-tracking experiments. Our results show that these saliency maps can obtain competitive results on benchmark saliency maps. On one synthetic saliency dataset this method even obtains the state-of-the-art without the need of ever having seen an actual saliency image for training.
Universitat Autònoma de Barcelona. Programa de Doctorat en Informàtica

Object recognition is a skill we as humans often take for granted. Due to our formidable object learning, recognition and generalisation skills, it is sometimes hard to see the multitude of obstacles that need to be overcome in order to replicate this skill in an artificial system. Object recognition is also one of the classical areas of computer vision, and many ways of approaching the problem have been proposed. Recently, visually capable robots and autonomous vehicles have increased the focus on embodied recognition systems and active visual search. These applications demand that systems can learn and adapt to their surroundings, and arrive at decisions in a reasonable amount of time, while maintaining high object recognition performance. This is especially challenging due to the high dimensionality of image data. In cases where end-to-end learning from pixels to output is needed, mechanisms designed to make inputs tractable are often necessary for less computationally capable embodied systems.Active visual search also means that mechanisms for attention and gaze control are integral to the object recognition procedure. Therefore, the way in which attention mechanisms should be introduced into feature extraction and estimation algorithms must be carefully considered when constructing a recognition system.This thesis describes work done on the components necessary for creating an embodied recognition system, specifically in the areas of decision uncertainty estimation, object segmentation from multiple cues, adaptation of stereo vision to a specific platform and setting, problem-specific feature selection, efficient estimator training and attentional modulation in convolutional neural networks. Contributions include the evaluation of methods and measures for predicting the potential uncertainty reduction that can be obtained from additional views of an object, allowing for adaptive target observations. Also, in order to separate a specific object from other parts of a scene, it is often necessary to combine multiple cues such as colour and depth in order to obtain satisfactory results. Therefore, a method for combining these using channel coding has been evaluated. In order to make use of three-dimensional spatial structure in recognition, a novel stereo vision algorithm extension along with a framework for automatic stereo tuning have also been investigated. Feature selection and efficient discriminant sampling for decision tree-based estimators have also been implemented. Finally, attentional multi-layer modulation of convolutional neural networks for recognition in cluttered scenes has been evaluated. Several of these components have been tested and evaluated on a purpose-built embodied recognition platform known as Eddie the Embodied.
Embodied Visual Object Recognition
FaceTrack

This thesis presents there important results in visual object recognition based on shape. (1) A new algorithm (RAST; Recognition by Adaptive Sudivisions of Tranformation space) is presented that has lower average-case complexity than any known recognition algorithm. (2) It is shown, both theoretically and empirically, that representing 3D objects as collections of 2D views (the "View-Based Approximation") is feasible and affects the reliability of 3D recognition systems no more than other commonly made approximations. (3) The problem of recognition in cluttered scenes is considered from a Bayesian perspective; the commonly-used "bounded-error errorsmeasure" is demonstrated to correspond to an independence assumption. It is shown that by modeling the statistical properties of real-scenes better, objects can be recognized more reliably.

A robot must recognize objects in its environment in order to complete numerous tasks. Significant progress has been made in modeling visual appearance for image recognition, but the performance of current state-of-the-art approaches still falls short of that required by applications. This thesis describes visual recognition methods that leverage the spatial information sources available on-board mobile robots, such as the position of the platform in the world and the range data from its sensors, in order to significantly improve performance. Our research includes: a physical robotic platform that is capable of state-of-the-art recognition performance; a re-usable data set that facilitates study of the robotic recognition problem by the scientific community; and a three dimensional object model that demonstrates improved robustness to clutter. Based on our 3D model, we describe algorithms that integrate information across viewpoints, relate objects to auxiliary 3D sensor information, plan paths to next-best-views, explicitly model object occlusions and reason about the sub-parts of objects in 3D. Our approaches have been proven experimentally on-board the Curious George robot platform, which placed first in an international object recognition challenge for mobile robots for several years. We have also collected a large set of visual experiences from a robot, annotated the true objects in this data and made it public to the research community for use in performance evaluation. A path planning system derived from our model has been shown to hasten confident recognition by allowing informative viewpoints to be observed quickly. In each case studied, our system demonstrates significant improvements in recognition rate, in particular on realistic cluttered scenes, which promises more successful task execution for robotic platforms in the future.

This thesis is dedicated to the active research topic of generic Visual Object Categorization(VOC), which can be widely used in many applications such as videoindexation and retrieval, video monitoring, security access control, automobile drivingsupport etc. Due to many realistic difficulties, it is still considered to be one ofthe most challenging problems in computer vision and pattern recognition. In thiscontext, we have proposed in this thesis our contributions, especially concerning thetwo main components of the methods addressing VOC problems, namely featureselection and image representation.Firstly, an Embedded Sequential Forward feature Selection algorithm (ESFS)has been proposed for VOC. Its aim is to select the most discriminant features forobtaining a good performance for the categorization. It is mainly based on thecommonly used sub-optimal search method Sequential Forward Selection (SFS),which relies on the simple principle to add incrementally most relevant features.However, ESFS not only adds incrementally most relevant features in each stepbut also merges them in an embedded way thanks to the concept of combinedmass functions from the evidence theory which also offers the benefit of obtaining acomputational cost much lower than the one of original SFS.Secondly, we have proposed novel image representations to model the visualcontent of an image, namely Polynomial Modeling and Statistical Measures basedImage Representation, called PMIR and SMIR respectively. They allow to overcomethe main drawback of the popular "bag of features" method which is the difficultyto fix the optimal size of the visual vocabulary. They have been tested along withour proposed region based features and SIFT. Two different fusion strategies, earlyand late, have also been considered to merge information from different "channels"represented by the different types of features.Thirdly, we have proposed two approaches for VOC relying on sparse representation,including a reconstructive method (R_SROC) as well as a reconstructiveand discriminative one (RD_SROC). Indeed, sparse representation model has beenoriginally used in signal processing as a powerful tool for acquiring, representingand compressing the high-dimensional signals. Thus, we have proposed to adaptthese interesting principles to the VOC problem. R_SROC relies on the intuitiveassumption that an image can be represented by a linear combination of trainingimages from the same category. Therefore, the sparse representations of images arefirst computed through solving the ℓ1 norm minimization problem and then usedas new feature vectors for images to be classified by traditional classifiers such asSVM. To improve the discrimination ability of the sparse representation to betterfit the classification problem, we have also proposed RD_SROC which includes adiscrimination term, such as Fisher discrimination measure or the output of a SVMclassifier, to the standard sparse representation objective function in order to learna reconstructive and discriminative dictionary. Moreover, we have also proposedChapter 0. Abstractto combine the reconstructive and discriminative dictionary and the adapted purereconstructive dictionary for a given category so that the discrimination power canfurther be increased.The efficiency of all the methods proposed in this thesis has been evaluated onpopular image datasets including SIMPLIcity, Caltech101 and Pascal2007.

As robotic systems move from well-controlled settings to increasingly unstructured environments, they are required to operate in highly dynamic and cluttered scenarios. Finding an object, estimating its pose, and tracking its pose over time within such scenarios are challenging problems. Although various approaches have been developed to tackle these problems, the scope of objects addressed and the robustness of solutions remain limited. In this thesis, we target a robust object perception using visual sensory information, which spans from the traditional monocular camera to the more recently emerged RGB-D sensor, in unstructured environments. Toward this goal, we address four critical challenges to robust 6-DOF object pose estimation and tracking that current state-of-the-art approaches have, as yet, failed to solve. The first challenge is how to increase the scope of objects by allowing visual perception to handle both textured and textureless objects. A large number of 3D object models are widely available in online object model databases, and these object models provide significant prior information including geometric shapes and photometric appearances. We note that using both geometric and photometric attributes available from these models enables us to handle both textured and textureless objects. This thesis presents our efforts to broaden the spectrum of objects to be handled by combining geometric and photometric features. The second challenge is how to dependably estimate and track the pose of an object despite the clutter in backgrounds. Difficulties in object perception rise with the degree of clutter. Background clutter is likely to lead to false measurements, and false measurements tend to result in inaccurate pose estimates. To tackle significant clutter in backgrounds, we present two multiple pose hypotheses frameworks: a particle filtering framework for tracking and a voting framework for pose estimation. Handling of object discontinuities during tracking, such as severe occlusions, disappearances, and blurring, presents another important challenge. In an ideal scenario, a tracked object is visible throughout the entirety of tracking. However, when an object happens to be occluded by other objects or disappears due to the motions of the object or the camera, difficulties ensue. Because the continuous tracking of an object is critical to robotic manipulation, we propose to devise a method to measure tracking quality and to re-initialize tracking as necessary. The final challenge we address is performing these tasks within real-time constraints. Our particle filtering and voting frameworks, while time-consuming, are composed of repetitive, simple and independent computations. Inspired by that observation, we propose to run massively parallelized frameworks on a GPU for those robotic perception tasks which must operate within strict time constraints.

This investigation deals with the issue of visual perception of the designed object, which is relevant in the context of product differentiation particularly in the case where incremental style changes are made to the external shape design of the product. Such cases present a problem regarding the effectiveness of product differentiation, which this research claims is a matter of visual perception. The problem is that in order for product differentiation to be effective, the design changes must be perceptible. Perceptible differentiation is explained as a function of the physical change, i.e. the Oreal¹ difference, and also of the relevance for the observer of that change, i.e. Operceived¹ difference. This study therefore focuses on the comparison between these two aspects of the designed object: the physical design and the perceived design. Literature from both material culture and the so-called indirect account of perception suggest that visual perception is an interpretation of the artefacts that we see. This visual perception is a function of the physical aspect of that object and of the individual cultural background of the observer. However, it was found that between these two accounts there are theoretical incompatibilities which this study claims could be resolved through scholarly investigation of visual perception of the designed object. The thesis takes these two accounts into consideration and proposes a more comprehensive model of visual perception of the designed object that details and extends the material culture understanding of what constitutes the perceptual experience with the designed object and the role of form in that experience. Theory building was conducted across the disciplines of psychology of perception and design. A revised model was proposed for the area of designed object studies, which was informed by Gregory¹s theoretical framework and incorporated empirical explorations into the model development process. The study therefore contributes knowledge to the research area of design, more specifically to cross-disciplinary methods for theory building on visual perception of the designed object.

We aim for mobile robots to function in a variety of common human environments, which requires them to efficiently search previously unseen target objects. We can exploit background knowledge about common spatial relations between landmark objects and target objects to narrow down search space. In this paper, we propose an active visual object search strategy method through our introduction of the Semantic Linking Maps (SLiM) model. SLiM simultaneously maintains the belief over a target object's location as well as landmark objects' locations, while accounting for probabilistic inter-object spatial relations. Based on SLiM, we describe a hybrid search strategy that selects the next best view pose for searching for the target object based on the maintained belief. We demonstrate the efficiency of our SLiM-based search strategy through comparative experiments in simulated environments. We further demonstrate the real-world applicability of SLiM-based search in scenarios with a Fetch mobile manipulation robot.

While recent deep neural networks have achieved a promising performance on object recognition, they rely implicitly on the visual contents of the whole image. In this paper, we train deep neural networks on the foreground (object) and background (context) regions of images respectively. Considering human recognition in the same situations, networks trained on the pure background without objects achieves highly reasonable recognition performance that beats humans by a large margin if only given context. However, humans still outperform networks with pure object available, which indicates networks and human beings have different mechanisms in understanding an image. Furthermore, we straightforwardly combine multiple trained networks to explore different visual cues learned by different networks. Experiments show that useful visual hints can be explicitly learned separately and then combined to achieve higher performance, which verifies the advantages of the proposed framework.