Stefan Oprea

Digital image processing applied in drugs industry for detection of broken aspirin tablets

Interest in digital image processing methods stems from two principal areas: improvement of pictorial information for human interpretation and processing of image data for storage, transmission, and representation for autonomous machine perception. Today, there is no area of technical endeavor that is not impacted in same way by digital image processing. A major area of imaging is in automated visual inspection of manufactured goods. A typical image processing task with products like this is to inspect them for missing or wrong parts. Detecting some anomalies is a major theme of industrial inspection that includes a large area of products. The proposed paper presents an application for detection of broken aspirin tablets using image processing techniques. The application was implemented in an object oriented image processing software. The processing scheme can be adapted for other practical applications from other domains.

Image processing techniques used for dental x-ray image analysis

Classification of dental caries is important for the diagnosis and treatment planning of the dental disease, which has been affecting a very large population throughout the globe. It is also helpful for conducting detailed study and investigations about the nature of the dental disease. Classification of dental diseases is decided on the basis of certain criteria, such as based on whether the lesion is within the enamel, dentin or whether it touches the pulp. Dental caries are, clearly visible in the X-ray changes and it can be detected from the caries lesion present in the radiographs. In this paper we propose to show how image processing techniques will help check the X-ray and examine the extent to which the caries lesion is present and then classify the type of caries present in the dental radiograph.

Microcontroller based tester for semiconductor devices

The system presented in this paper represents an enhanced tester for active devices. It ensure the identification of the transistor type (PNP, NPN, JFET, n-MOS, p-MOS) connected to the test terminals, can detect the disposing of the components terminals in the package and also can measure the gain factor of the bipolar transistors. In addition, the proposed module can measure the channel resistance of field effect transistors (FET) and threshold voltage for metal-oxide transistors (MOS). The measurement results for the tested device are presented on an LCD display. The system is based on PIC16F872 microcontroller which manage the voltages applied to the three test terminals where is connected the semiconductor device. The system is battery operated. By using the microcontroller technology and very few external components, it is obtained a portable and versatile apparatus that allows quick and accurate measurements on active electronic components.

Determination of Misplaced Drill Holes on a PCB

The paper presents an application for determination of misplaced drills on printed circuit board. The algorithm proposed in this paper uses image processing techniques for automated optical inspection and does not requires the original image of the PCB (original mask). The software application was developed in Imagproc as well as in Matlab and can be adapted for another type of PCB verification or for automated optical verification in other domains.

Digital image processing applied in determination of misplaced components on a PCB, marked with colour code

The paper presents an application for automatic determination of misplaced components or missing components mounted on a PCB. The determination is realized by image processing techniques using frame processing methods. The advantage of using this inspection method is that of automation facilities and quickly determination of misplaced components marked with colour code. The proposed algorithm can be implemented in different programs as Matlab, Imagproc, so on....

Remote measurements in educational laboratories using LabVIEW and DAQ cards

This paper presents an application used in educational laboratory for multiple waveform measurement and display, for analysing of the operation of electronically circuits. It was implemented as virtual instrument in LabVIEW and uses a data acquisition card for electrical signals acquisition. The application can be used in educational laboratory for multiple signals measurement, record and time correlated displaying to help students to better understand the operation of the complex electronic circuits. Using the facilities offered by LabVIEW, this application was implemented to be accessed remotely for online measurement.

Simulation of signals in digital television using LabVIEW

This paper presents an application for generating of all the signals in case of digital televisions corresponding to standard colour bar patterns, from primary RGB signals to YCbCr colour space digital signals. It was implemented in LabVIEW and can represents D1 and D2 format for DTV signals on 8 and 10 bits resolution. The application can be used for DTV signals teaching and analysing in case of different image patterns.

GSM based remote control for distributed systems

In this paper are presented the results regarding the implementation and testing of a novel type of remote control based on the data transmission facilities offered by the GSM network infrastructure and the processing power achieved by new generation of microcontrollers. The system is intended to be used in the development of complex distributed control applications that are specific to various automated industrial processes, including the manufacturing of printed circuit boards and electronic modules. The proposed control system was designed using a prototype board equipped with Atmega 328 microcontroller. For implementation of data communication between the remote modules that compose the distributed control system a Quectel M10 quad-band GSM/GPRS radio modem was used. The quality of the proposed design was evaluated through extended performances analysis focused on the delay time, maximum transfer rate, failure tolerance and reliability. The system allows versatile configuration of commands structure and can operate with an extended set of commands for the remote modules. Also, compared with other implementation solutions the proposed design can be used almost in any location due to the large availability of the GSM infrastructure.

Reconfigurable signal generator and simulator for testing the digital transmission circuits

In this article is presented the implementation of a new type of reconfigurable signal generator and simulator used for testing digital transmission circuits that requires complex modulated waveforms. In our experiments we choose as an example the quadrature amplitude modulation or quadrature phase shift keying (QAM/QPSK) signals. The proposed solution is based on a high-speed NI-USB-6251Mdata acquisition board connected to a computer running a LabVIEWapplication. The analog outputs of the board are used for applying the predefined test signals to the circuits that are under test. The response of the tested circuit is monitored using the inputs of the data acquisition board. The novelty of the proposed system is given by the association between a very flexible and user friendly graphical programming environment such as LabVIEW and a general purpose data acquisition board which lead to an attractive implementation solution for a virtual instrument capable to simulate, generate, and also test a multitude of circuits using various signals. Compared with the classical approaches, the system presented in this paper represents a versatile platform, with large spectrum of applications because, with proper configuration of the software application, can be generated a broad range of modulated signals, including arbitrary waveforms, the only limitation being the speed of the data acquisition/generation module.

Wireless technologies for distributed sensor networks used in measurement and automation systems

In this paper we present the modern wireless technologies for realization of distributed measurement and automation systems. The new radio transmission technologies and protocols like Wi-Fi, ZigBee, Bluetooth offer facile way for connections between sensors and devices from a complex measurement system. The first part of the paper contains a general overview of these techniques, making a comparatively analysis of their performances and facilities, useful in the design and implementation of measurement systems. In the last part of the paper we present an application for temperature measurement and monitoring with ZigBee communication. The measurement system was implemented with MegaAVR development board.