Live Demonstration: On the distance estimation of moving targets with a Stereo-Vision AER system

Distance calculation is always one of the most important goals in a digital stereoscopic vision system. In an AER system this goal is very important too, but it cannot be calculated as accurately as we would like. This demonstration shows a first approximation in this field, using a disparity algorithm between both retinas. The system can make a distance approach about a moving object, more specifically, a qualitative estimation. Taking into account the stereo vision system features, the previous retina positioning and the very important Hold&Fire building block, we are able to make a correlation between the spike rate of the disparity and the distance.Ministerio de Ciencia e Innovación TEC2009-10639-C04-0

Building Blocks for Spikes Signals Processing

Neuromorphic engineers study models and implementations of systems that mimic neurons behavior in the brain. Neuro-inspired systems commonly use spikes to represent information. This representation has several advantages: its robustness to noise thanks to repetition, its continuous and analog information representation using digital pulses, its capacity of pre-processing during transmission time, ... , Furthermore, spikes is an efficient way, found by nature, to codify, transmit and process information. In this paper we propose, design, and analyze neuro-inspired building blocks that can perform spike-based analog filters used in signal processing. We present a VHDL implementation for FPGA. Presented building blocks take advantages of the spike rate coded representation to perform a massively parallel processing without complex hardware units, like floating point arithmetic units, or a large memory. Those low requirements of hardware allow the integration of a high number of blocks inside a FPGA, allowing to process fully in parallel several spikes coded signals.Junta de Andalucía P06-TIC-O1417Ministerio de Ciencia e Innovación TEC2009-10639-C04-02Ministerio de Ciencia e Innovación TEC2006-11730-C03-0

Self-Organization in a Parametrically Coupled Logistic Map Network: A Model for Information Processing in the Visual Cortex

In this paper, a new model seeking to emulate the way the visual cortex processes information and interacts with subcortical areas to produce higher level brain functions is described. We developed a macroscopic approach that incorporates salient attributes of the cortex based on combining tools of nonlinear dynamics, information theory, and the known organizational and anatomical features of cortex. Justifications for this approach and demonstration of its effectiveness are presented. We also demonstrate certain capabilities of this model in producing efficient sparse representations and providing the cortical computational maps

Estimación de distancias mediante un sistema de estéreo-visión basado en retinas DVS

La estimación de distancias es uno de los objetivos más importantes en todo sistema de visión artificial. Para poder llevarse a cabo, es necesaria la presencia de más de un sensor de visión para poder enfocar los objetos desde más de un punto de vista y poder aplicar la geometría de la escena con tal fin. El uso de sensores DVS supone una diferencia notable, puesto que la información recibida hace referencia únicamente a los objetos que se encuentren en movimiento dentro de la escena. Este aspecto y la codificación de la información utilizada hace necesario el uso de un sistema de procesamiento especializado que, en busca de la autonomía y la paralelización, se integra en una FGPA. Esta demostración integra un escenario fijo, donde un objeto móvil realiza un movimiento continuo acercándose y alejándose del sistema de visión estéreo; tras el procesamiento de esta información, se aporta una estimación cualitativa de la posición del objeto.Image processing in digital computer systems usually considers the visual information as a sequence of frames. Digital video processing has to process each frame in order to obtain a result or detect a feature. In stereo vision, existing algorithms used for distance estimation use frames from two digital cameras and process them pixel by pixel to obtain similarities and differences from both frames; after that, it is calculated an estimation about the distance of the different objects of the scene. Spike-based processing implements the processing by manipulating spikes one by one at the time they are transmitted, like human brain. The mammal nervous system is able to solve much more complex problems, such as visual recognition by manipulating neuron’s spikes. The spike-based philosophy for visual information processing based on the neuro-inspired Address-Event- Representation (AER) is achieving nowadays very high performances. In this work, it is proposed a two-DVS-retina connected to a Virtex5 FPGA framework, which allows us to obtain a distance approach of the moving objects in a close environment. It is also proposed a Multi Hold&Fire algorithm in VHDL that obtains the differences between the two retina output streams of spikes; and a VHDL distance estimator.Plan Propio de la Universidad de Sevilla Proyecto: 2017/00000962Ministerio de Industria, Competitividad e Innovación (España) COFNET TEC2016-77785-

Applying Improve Differential Evolution Algorithm for Solving Gait Generation Problem of Humanoid Robots

This chapter addresses an approach to generate 3D gait for humanoid robots. The proposed method considers gait generation matter as optimization problem with constraints. Firstly, trigonometric function is used to produce trial gait data for conducting simulation. By collecting the result, we build an approximation model to predict final status of the robot in locomotion, and construct optimization problem with constraints. In next step, we apply an improve differential evolution algorithm with Gauss distribution for solving optimization problem and achieve better gait data for the robot. This approach is validated using Kondo robot in a simulated dynamic environment. The 3D gait of the robot is compared to human in walk

Features selection for human activity recognition with iPhone inertial sensors

The recognition of human activities through sensors embedded in smart-phone devices, such as iPhone, is attracting researchers due to its relevance. The advances of this kind of technology are making possible the widespread and pervasiveness of sensing technology to take advantage of multiple sources of sensing to enrich users experience or to achieve proactive, context-aware applications and services. Human activity recognition and monitoring involves a continuing analysis of large amounts of data so, any increase or decrease in accuracy results in a wide variation in the number of activities correctly classied and incorrectly classied, so it is very important to increase the rate of correct classication. We have researched on a vector with 159 different features and on the vector subsets in order to improve the human activities recognition. We extracted features from the Magnitude of the Signal, the raw signal data, the vertical acceleration, the Horizontal acceleration, and the ltered Raw data. In the evaluation process we used the classiers: Naive Bayes, K-Nearest Neighbor and Random Forest. The features wereextracted using the java programming language and the evaluation was done with WEKA. The maximum accuracy was obtained, as expected, with Random Forest using all the 159 features. The best subset found has twelve features: the Pearson correlation between vertical acceleration and horizontal acceleration, the Pearson correlation between x and y, the Pearson correlation between x and z, the STD of acceleration z,the STD of digital compass y, the STD of digital compass z, the STD of digital compass x, the mean between axis, the energy of digital compass x, the mean of acceleration x, the mean of acceleration z, the median of acceleration z

People detection, tracking and biometric data extraction using a single camera for retail usage

Tato práce se zabývá návrhem frameworku, který slouží k analýze video sekvencí z RGB kamery. Framework využívá technik sledování osob a následné extrakce biometrických dat. Biometrická data jsou sbírána za účelem využití v malobochodním prostředí. Navržený framework lze rozdělit do třech menších komponent, tj. detektor osob, sledovač osob a extraktor biometrických dat. Navržený detektor osob využívá různé architektury sítí hlubokého učení k určení polohy osob. Řešení pro sledování osob se řídí známým postupem \uv{online tracking-by-detection} a je navrženo tak, aby bylo robustní vůči zalidněným scénám. Toho je dosaženo začleněním dvou metrik týkající se vzhledu a stavu objektu v asociační fázi. Kromě výpočtu těchto deskriptorů, jsme schopni získat další informace o jednotlivcích jako je věk, pohlaví, emoce, výška a trajektorie. Návržené řešení je ověřeno na datasetu, který je vytvořen speciálně pro tuto úlohu.This thesis proposes a framework that analyzes video sequences from a single RGB camera by extracting useful soft-biometric data about tracked people. The aim is to focus on data that could be utilized in a retail environment. The designed framework can be broken down into the smaller components, i.e., people detector, people tracker, and soft-biometrics extractor. The people detector employs various deep learning architectures that estimate bounding boxes of individuals. The tracking solution follows the well-known online tracking-by-detection approach, while the proposed solution is built to be robust regarding the crowded scenes by incorporating appearance and state features in the matching phase. Apart from calculating appearance descriptors only for matching, we extract additional information of each person in the form of age, gender, emotion, height, and trajectory when possible. The whole framework is validated against the dataset which was created for this propose

Hardware implementation of a spiking neural network for fast synchronization

In this master thesis, we present two different hardware implementations of the Oscillatory Dynamic Link Matcher (ODLM). The ODLM is an algorithm which uses the synchronization in a network of spiking neurons to realize different signal processing tasks. The main objective of this work is to identify the key design choices leading to the efficient implementation of an embedded version of the ODLM. The resulting systems have been tested with image segmentation and image matching tasks. The first system is bit-slice and time-driven. The state of the whole network is updated at regular time intervals. The system uses a bit-slice architecture with a large number of processing elements. Each processing element, or slice, implements one neuron of the network and takes the form of a column on the hardware. The columns are placed side by side and they are locally connected to their 2 neighbors. This local hardware connection scheme makes the system scalable, which means that columns can be easily added to increase the capacity of the system. Each column consists of a weight vector, a synapse model unit and a membrane model unit. The system can implement any network topology, making it very flexible. The function governing the time evolution of the neurons' membrane potential is approximated by a piece-wise linear function to reduce the amount of logical resources required. With this system, a fully-connected network of 648 neurons can be implemented on a Virtex-5 Xilinx XC5VSX5OT FPGA clocked at 100 MHz. The system is designed to process simultaneous spikes in parallel, reaching a maximum processing speed of 6 Mspikes/s. It can segment a 23×23 pixel image in 2 seconds and match two pre-segmented 90×30 pixel images in 550 ms. The second system is event-driven. A single processing element sequentially processes the spikes. This processing element is a 5-stage pipeline which can process an average of 1 synapse per 7 clock cycles. The synaptic weights are not stored in memory in this system, they are computed on-the-fly as spikes are processed. The topology of the network is also resolved during operation, and the system supports various regular topologies like 8-neighbor and fully-connected. The membrane potential time evolution function is computed with high precision using a look-up table. On the Virtex-5 FPGA, a network of 65 536 neurons can be implemented and a 406×158 pixel image can be segmented in 200 ms. The FPGA can be clocked at 100 MHz. Most of the design choices made for the second system are well adapted to the hardware implementation of the ODLM. In the original ODLM, the weight values do not change over time and usually depend on a single variable. It is therefore beneficial to compute the weights on the fly rather than saving them in a huge memory bank. The event-driven approach is a very efficient strategy. It reduces the amount of computations required to run the network and the amount of data moved in and out of memory. Finally, the precise computation of the neurons' membrane potential increases the convergence speed of the network

COMPOSITE KERNEL FEATURE ANALYSIS FOR CANCER CLASSIFICATION

Computed tomographic (CT) colonography, or virtual colonoscopy, is a promising technique for screening colorectal cancers by use of CT scans of the colon. Current CT technology allows a single image set of the colon to be acquired in 10-20 seconds, which translates into an easier, more comfortable examination than is available with other screening tests. Currently, however, interpretation of an entire CT colonography examination is time-consuming, and the reader performance for polyp detection varies substantially. To overcome these difficulties while providing a high detection performance of polyps, researchers are developing computer-aided detection (CAD) schemes that automatically detect suspicious lesions in CT colonography images. The overall goal of this study is to achieve a high performance in the detection of polyps on CT colonographic images by effectively incorporating an appearance-based object recognition approaches into a model-based CAD scheme. Our studies are focused in developing a fast kernel feature analysis that can efficiently differentiate polyps from false positives and thus improve the detection performance of polyps. We have developed a novel method of selecting kernel functions that are appropriate for the given data set and then use their linear combination in the construction of Kernel Gram matrix which can then used for efficient reconstruction of feature space. The main contribution of this work lies in providing a Composite kernel Matrix that involves appearance-based approach to improve kernel feature analysis for the classification of texture-based features. We evaluated our proposed kernel feature analysis on texture-based features that were extracted from the polyp candidates generated by our shape-based CAD scheme