Design and Implementation of a Personal Computer Authorization System using Color Detection

F. Yucel, O. Oral Department of Informatics, Akdeniz University N. Caglayan Department of Farm Machinery, Faculty of Agriculture, Akdeniz University M. Tecimen, S. Kocak Department of Informatics Technologies, Antalya Serik Vocational High School E. Yuce Department of Electrical&Electronics Engineering, Pamukkale University, Dumlupinar Blv., Antalya, Turkey, phone: +90 242 310 60 37, e-mail: fyucel@akdeniz.edu.tr


Introduction
Today, the computer authorization and to access information is very important problem for schools, institutions, companies and organizations.The central objective of any security system is the ability to prevent undesired access, while still allowing authorized access to information.As computer usage expands into more areas and the number and variety of users increase, we expect to see an increased demand for more complex security provisions [1].
There are different types of user authentication to make personal computers (PCs) secure.Traditionally, verified users have gained the access via passwords, Personal Identification Numbers (PINs), or smart cards [2].Recently, biometrics has been received considerable attentions, which refers the personal biological or behavioral characteristics used for verification or identification.Biometric systems make use of fingerprints, hand geometry, iris, retina, face, hand vein, facial thermograms, signature or voiceprint to verify a person's identity [3].But, these systems cannot provide a practical and costeffective solution for PCs which have more than the number of users and which users' change frequently.For example, an easily-updatable security system can be created to use each of PCs by different students in information technologies (IT) classrooms.
Color sensing has a variety of applications including detection of environmental, biological, and chemical parameters [4].In this study, to ensure the authorization of computer usage, a color recognition system has been developed by applying a color sensor (TCS230).For this purpose, color coded cards are prepared and defined for each computer.A color code is printed by using one or more color tone on the card.The color codes on the card detected by a color sensor.The color sensor generates the output signal in square waveform which frequency varied directly with the hue of color in RGB (red, green, blue) color system [5,6].The decoders which recognize the signal frequencies obtained from the sensor are located inside of the computer cases.Each decoder can recognize different color coded cards.If computer user puts the color coded card into the color decoder correctly, the decoder allows switch on the power supply of computer.Otherwise, the decoder does not allow to work of computer and it warns the user by providing both voice and visual message.This study shows that it can also be used color recognition for authorization problems as different from other usage fields of it.Proposed method can also be used cost-efficiently and to be preferable for PCs which users are often changed.

Color theory
There are many standard color systems used nowadays in various applications, but most standards generally hold some common idea, that is, the color representation in 3-dimension space.For instance, in RGB color system; there are three color axes for Red, Green, and Blue.RGB HSV (Hue Saturation Value) is a popular color system [6].
Also other recent studies have established that there are three different types of cones in the human retina and their spectral responses can be represented as S 1 (λ), S 2 (λ) and S 3 (λ) where, λ min = 380 nm and λ max = 780 nm.Light is a type of energy, which makes up a small portion of the electromagnetic spectrum.Visible light could be expressed as a frequency, but the magnitude is so large people The CIE measurements source.In the mixing relativ green (Y), and x(λ), y(λ), and needed to ma constant-width spectrum.The the perceived calculated dir 

Fig
Fig. 1.System b Hardware-ba detection met Designed high resolutio decoder and a 1).Previously cards with col on these cards code database coordinate on (TCS230) con sent to RGB c from the sens Fig. Fig.