Standard TV Camera Research Articles

Automatic Detection of Anomalous Events for Advanced Real-Time Video Surveillance

This paper introduces the architecture and the implementation details of an automatic real-time video surveillance system, capable of autonomously detecting anomalous events. Nowadays, video surveillance systems are not flexible in adapting to different operative scenarios (they only work well in known and structured environments) and generally need human assistance to recognize and tag specific visual events. The proposed system can automatically adapt to different scenarios without human intervention (but the placement of the TV sensors), and automatically leans the “typical” targets behavior in each specific operative environment by means of robust self-learning techniques. The learned knowledge is used by the system to give alerts in an automatic way by analyzing the trajectories of visual targets in the controlled scene. Robustness is obtained through an improved version of the Altruistic Vector Quantization algorithm (AVQ). The modified AVQ autonomously establishes the number of trajectory prototypes, and improves the representativeness of the prototypes themselves. Anomalies are detected if visual trajectories deviate from the “typical” learned prototypes. Standard PCs and TV cameras have been used for the actual implementation, that has been tested in many real indoor and outdoor environments. Currently real time performance has been obtained (15 fps for each camera). A preliminary learning period (about 20 minutes to grant a suitable time interval to learn all the “typical” visual trajectories) is necessary. After that period the system gives automatic alerts about events that do not conform to typical behaviors. The field view can be changed (by panning the TV camera, for example), then the system relearns the new scenario without any human intervention (no thresholds or other settings) and accurately detects anomalous events.

A human face profile identification system using 1-D real Fourier descriptors

Over the last twenty years, researchers in the field of human face recognition have tried to answer the question, how can a face be formally described? Each new face recognition system provides a different answer. In this paper, the face profile is represented using a real Fourier descriptor. Outlines of face profiles are extracted from back-lit images captured using a CCIR standard TV camera and frame-grabber. Points on the nose tip and chin are extracted and used to standardise the orientation and scale of the profile. The face curve is sampled uniformly in the vertical direction and transformed from a 2-D to a 1-D representation. After Fourier transformation, a small number of the resulting coefficients are used as a feature vector. This descriptor is insensitive to translation, scale and orientation of the original face profile. Applications to face recognition and reconstruction are illustrated and discussed in the paper.

Capillary characteristics of high temperature melts measured by sessile-drop method using computer-aided TV system

An automated TV system with a computer for measuring the capillary constant, surface tension, density, and wetting angles of melts by the sessile-drop method is described. Hardware and software support issues have been treated. Surface tension and density of a number of high temperature melts, including copper, CaF2, and alloys Pb+0.34 at %S, 5Cu+0.5Ge+94.5Sn (at%) were measured. The surface tension-concentration isotherm (1100 °C) obtained for the Cu-alloy Ga-Ge (1∶1) system was found to have a smooth run and show a sharp decrease of surface tension σlg on adding of Ga-Ge alloy to copper. The obtained results are in good agreement with the manual measurements data. The use of a standard TV camera (625 lines) as a data acquisition device with the subsequent statistical processing of data was found to provide the accuracy of surface tension determination within the range of 1% and an appreciable measurement time reduction.

Three-dimensional reconstruction of Paramecium primaurelia oral apparatus through confocal laser scanning optical microscopy

The oral apparatus of the ciliate protozoan Paramecium primaurelia, a single-celled eukaryotic organism, is a highly organized structure whose arrangement is of important taxonomic, phylogenetic and developmental significance. This paper analyses oral structures by means of a confocal laser scanning optical microscope (CLSM), which allows their three-dimensional visualization and measurement. The extraction of the intrinsic three-dimensional information related to the biological objects under investigation can in turn be related to their functional state, according to the classical paradigms of structure to function relationship identification. In our experiments, we acquired different data sets. These are optical slices of the biological sample under investigation, acquired in a confocal situation, through epi-illumination, in reflection. For comparison with conventional microscopy, two-dimensional images were acquired via a standard TV camera coupled to the microscope itself. The volumes obtained by piling up the slices were rendered through different techniques, some of them directly implemented on the workstation controlling the CLSM system, some of them on a SUN SPARCstation 1, where the original data were transferred via an Ethernet link. In this last instance, original software has been developed for the visualization and animation of the three-dimensional structures, under UNIX and X-Window, according to a ray-tracing algorithm.

ELITE: A goal oriented vision system for moving objects detection

SUMMARYA specially designed system for movement monitoring is here presented. The system has a two level architecture. At the first level, a hardware processor analyses in real-time the images provided by a set of standard TV cameras and, using a technique based on the convolution operator, recognizes in each frame objects that have a specific shape. The coordinates of these objects are fed to a computer, the second level of the system, that analyses the movement of these objects with the aid of a set of rules representing the knowledge of the context. The system was extensively tested on the field and the main results are reported.The whole system can work as a controlling device in robotics or as a general real-time image processor as well as an automatic movement analyser in biomechanics, orthopedic and neurological medicine.

Determining reflectance properties of an object using range and brightness images

The authors discuss a method of recovering reflectance properties of a surface from a range image given by a range finder and a brightness image given by a standard TV camera. The Torrance-Sparrow model is used for the reflectance model. The model consists of the Lambertian and specular components: its reflectance properties consist of the relative strength between the Lambertian and specular components and specular sharpness as well as light source direction. An iterative least square fitting method is used to obtain these parameters based on the range and brightness images. An input image is segmented into four different parts using the parameters: Lambertian reflection, specular reflection, interreflection, and shadow part. The authors also reconstruct ideal images that consist of only Lambertian or specular reflection. >

An algorithm for 3-D automatic movement detection by means of standard TV cameras

An algorithm for the computation of 3-D coordinates (space intersection) of marked points on a moving subject surveyed by a couple of TV cameras is presented herein. It has been designed in order to meet the requirements of routinary analysis in biomechanic laboratories. 3-D geometrical arrangement of the TV cameras (space resection) is obtained by means of a method which is based on an iterative least-squares estimation and requires little time for calibration operations; 3-D coordinates are computed by means of a fast geometrical intersection algorithm. The whole algorithm has been extensively used in different laboratories and results on its reliability and accuracy are reported.

Tandem scanning confocal light microscopy as compared with x-ray diffraction for characterizing the behavior of clays in fluid-saturated petroleum reservoir rock

Many techniques of imaging used to characterize petroleum reservoir rocks are applied to dehydrated specimens. In order to directly study behavior of fines in reservoir rock at conditions similar to those found in-situ these materials need to be characterized in a fluid saturated state.Standard light microscopy can be used on wet specimens but depth of field and focus cannot be obtained; by using the Tandem Scanning Confocal Microscope (TSM) images can be produced from thin focused layers with high contrast and resolution. Optical sectioning and extended focus images are then produced with the microscope. The TSM uses reflected light, bulk specimens, and wet samples as opposed to thin section analysis used in standard light microscopy. The TSM also has additional advantages: the high scan speed, the ability to use a variety of light sources to produce real color images, and the simple, small size scanning system. The TSM has frame rates in excess of normal TV rates with many more lines of resolution. This is accomplished by incorporating a method of parallel image scanning and detection. The parallel scanning in the TSM is accomplished by means of multiple apertures in a disk which is positioned in the intermediate image plane of the objective lens. Thousands of apertures are distributed in an annulus, so that as the disk is spun, the specimen is illuminated simultaneously by a large number of scanning beams with uniform illumination. The high frame speeds greatly simplify the task of image recording since any of the normally used devices such as photographic cameras, normal or low light TV cameras, VCR or optical disks can be used without modification. Any frame store device compatible with a standard TV camera may be used to digitize TSM images.

A microcomputer-based solid-state nuclear track image analyzer

A microcomputer-based image processing system has been developed to use with solid-state nuclear track detectors for number counting, area measurement, and location identification. The image digitizer is designed to interface with a microcomputer and a standard black and white TV camera for data acquisition. A spatial dependent segmentation algorithm is proposed for track identification under nonuniform illumination and the low track-pixel population conditions. The system has been tested using Lexan samples irradiated by a Cf-252 spontaneous fission source. The counting accuracy is approximately 3% with a long term stability of 5%. Efficiency calibration was performed using samples with track densities up to 104/mm2. Results indicate that the proposed track identification scheme tends to reduce the track overlap effect and the system behaves as a nonparalyzable counting system. For track densities below 3000/mm2, either a paralyzable or a nonparalyzable counter model can be established with an accuracy better than 0.5%. For track densities below 1500/mm2, the track registration efficiency is in good agreement with manual counting results.

Development of a spectroscopically resolved multichannel image camera for a sounding rocket and satellite

An onboard model of a TV camera to detect spectroscopically resolved images has been developed. It has been able to detect several spectral pictures at the same time by using only one camera with no restriction against spectral selection between each picture. The wavelength of each picture has been selected electronically. The number of spectroscopically resolved pictures is dependent only on the memory size of the computer. This camera is equivalent to a standard TV camera in which 117 bandpass filters are installed. The favorable characteristics of this camera are that it does not cause a time difference between each picture and is able to display the physical parameters by numerical calculations and can change the spectral range even after launch. The principal purpose of this model is to assist in investigating the dynamic structure of the aurora and the atmospheric composition of planets.

RAPAC: a high-speed image-processing system

The paper describes the design and operation of a real-time image processing system and outlines one of its application areas. The system consists of a dedicated hardware processor called RAPAC (a reconfigurable attached processor architecture for convolution) and a host computer which is used for algorithm development and RAPAC control. RAPAC uses hardware processor units and multiple image memories, in a software controlled architecture, to process 5 MHz streams of pixel data. This processing rate allows it to process a 256 × 256 pixel image in 20 ms, one field time of a standard TV camera. The result is either a new 256 × 256 pixel image generated from the old image or a reduced data set which describes attributes of features in the image. These attributes are used by the host computer to calculate a decision output concerning the content of the image.

Quantitative autoradiography of central neurotransmitter receptors: methodological and statistical aspects with special reference to computer-assisted image analysis.

In the last few years, quantitative receptor autoradiography has been extensively employed to study the distribution and the functional role of area-specific transmitter receptors in the central nervous system. In the present paper we have developed quantitative methodologies for the analysis of autoradiograms using computerized image analysers coupled with standard TV camera input for the microdensitometrical evaluations. These procedures include the assessment of the film response to radioactivity using appropriate standards calibrated according to brain tissue quenching and non-linear conversion of density measurements in radioactivity values adopting the best mathematical model fitting to give as little variability as possible in the transformations. The reliability of the proposed approach has also been evaluated by means of a computer-assisted Monte Carlo simulation and parallel biochemical determinations.

Submillimeter laser interferometry with pyroelectric image recording

The interferometer with a submillimeter laser and standard pyroelectric TV camera for visualization of interference fringe pattern is described. Problems typical for the development of such interferometer are solved by choosing of a proper arrangement and a mutual spacing of its elements with respect to laser. The interferograms of a teflon wedge and an arcing plasma are presented as an example.

Low light level imaging using a standard TV camera with a videorecorder

Low light level imaging is possible using a standard TV camera with a video recorder, if the integration properties of the vidicon tubes or CCDs are exploited. Only a simple additional electronic circuit is necessary. The field of application is for static or slowly variable images, the integration time being about equal to the sampling period. Analogue image display and computer acquisition is performed off-line using the standard video signal from the video recorder.

Digitizing line drawings using a standard TV camera

Digitizing line drawings using a standard TV camera