75 research outputs found
Real-Time Implementation and Performance Optimization of Local Derivative Pattern Algorithm on GPUs
Pattern based texture descriptors are widely used in Content Based Image Retrieval (CBIR) for efficient retrieval of matching images. Local Derivative Pattern (LDP), a higher order local pattern operator, originally proposed for face recognition, encodes the distinctive spatial relationships contained in a local region of an image as the feature vector. LDP efficiently extracts finer details and provides efficient retrieval however, it was proposed for images of limited resolution. Over the period of time the development in the digital image sensors had paid way for capturing images at a very high resolution. LDP algorithm though very efficient in content-based image retrieval did not scale well when capturing features from such high-resolution images as it becomes computationally very expensive. This paper proposes how to efficiently extract parallelism from the LDP algorithm and strategies for optimally implementing it by exploiting some inherent General-Purpose Graphics Processing Unit (GPGPU) characteristics. By optimally configuring the GPGPU kernels, image retrieval was performed at a much faster rate. The LDP algorithm was ported on to Compute Unified Device Architecture (CUDA) supported GPGPU and a maximum speed up of around 240x was achieved as compared to its sequential counterpart
Post Event Investigation of Multi-stream Video Data Utilizing Hadoop Cluster
Rapid advancement in technology and in-expensive camera has raised the necessity of monitoring systems for surveillance applications. As a result data acquired from numerous cameras deployed for surveillance is tremendous. When an event is triggered then, manually investigating such a massive data is a complex task. Thus it is essential to explore an approach that, can store massive multi-stream video data as well as, process them to find useful information. To address the challenge of storing and processing multi-stream video data, we have used Hadoop, which has grown into a leading computing model for data intensive applications. In this paper we propose a novel technique for performing post event investigation on stored surveillance video data. Our algorithm stores video data in HDFS in such a way that it efficiently identifies the location of data from HDFS based on the time of occurrence of event and perform further processing. To prove efficiency of our proposed work, we have performed event detection in the video based on the time period provided by the user. In order to estimate the performance of our approach, we evaluated the storage and processing of video data by varying (i) pixel resolution of video frame (ii) size of video data (iii) number of reducers (workers) executing the task (iv) the number of nodes in the cluster. The proposed framework efficiently achieve speed up of 5.9 for large files of 1024X1024 pixel resolution video frames thus makes it appropriate for the feasible practical deployment in any applications
Motion Detection in Low Resolution Grayscale Videos Using Fast Normalized Cross Correrelation on GP-GPU
Motion estimation (ME) has been widely used in many computer vision applications, such as object tracking, object detection, pattern recognition and video compression. The most popular block based similarity measures are the sum of absolute differences (SAD), the sum of squared differences (SSD) and the normalized cross correlation (NCC). Similarity measure obtained using NCC is more robust under varying illumination changes as compared to SAD and SSD. However NCC is computationally expensive and application of NCC using full or exhaustive search method further increases required computational time. Relatively efficient way of calculating the NCC is to pre-compute sum-tables to perform the normalization referred to as fast NCC (FCC). In this paper we propose real time implementation of full search FCC algorithm applied to gray scale videos using NVIDIA’s Compute Unified Device Architecture (CUDA). We present fine-grained optimization techniques for fully exploiting computational capacity of CUDA. Novel parallelization strategies adopted for extracting data parallelism substantially reduce computational time of exhaustive FCC. We show that by efficient utilization of global, shared and texture memories available on CUDA, we can obtain the speedup of the order of 10x as compared to the sequential implementation of FCC
Efficient Storage and Processing of Video Data for Moving Object Detection Using Hadoop/MapReduce
Scalable Semi-Supervised Clustering for Face Recognition with Insufficient Labelled Samples
Hadoop, MapReduce and HDFS: A Developers Perspective
AbstractThe applications running on Hadoop clusters are increasing day by day. This is due to the fact that organizations have found a simple and efficient model that works well in distributed environment. The model is built to work efficiently on thousands of machines and massive data sets using commodity hardware. HDFS and MapReduce is a scalable and fault-tolerant model that hides all the complexities for Big Data analytics. Since Hadoop is becoming increasingly popular, understanding technical details becomes essential. This fact inspired us to explore Hadoop and its components in-depth. The process of analysing, examining and processing huge amount of unstructured data to extract required information has been a challenge. In this paper we discuss Hadoop and its components in detail which comprise of MapReduce and Hadoop Distributed File System (HDFS). MapReduce engine uses JobTracker and TaskTracker that handle monitoring and execution of job. HDFS a distributed file-system which comprise of NameNode, DataNode and Secondary NameNode for efficient handling of distributed storage purpose. The details provided can be used for developing large scale distributed applications that can exploit computational power of multiple nodes for data and compute intensive applications
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