فهرست مطالب

Majlesi Journal of Multimedia Processing
Volume:4 Issue: 4, Dec 2015

  • تاریخ انتشار: 1394/10/10
  • تعداد عناوین: 4
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  • Hooman A. Kashanian, Hamidreza B. Ghaffary, Nasrin C. Bagherzadeh, Sadaf D. Roostaie*, Haniyeh E. Alidoost Page 1
    Terahertz imaging is a safe and inexpensive imaging technique with medical applications. However, presently there is no consensus on the methods which can be used to analyze the data resulted from this technique. This can constrain further developments in this technique. In this study, database of terahertz images, prepared from gastric cancer, is analyzed. There are 17 parameters for analyzing terahertz images. In this study, initially decision trees and principal component analysis (PCA) are used to identify important parameters, and then Support Vector Machines and Artificial Neural Networks are employed to classify terahertz data in order to find both healthy and unhealthy samples. Eventually, regarding the optimal results of this study, we can suggest new methods in terahertz reflective imaging for cancerous samples.
    Keywords: Terahertz, Decision Tree, Gastric Cancer, Neural Networks, Support Vector Machines
  • Shadi. Saneie, Alireza. Naghsh* Page 9
    With rapid development of digital technology, protecting information such as copyright, content ownership confirmation has become more important. In image watermarking, information of the image is inserted such that the visual quality of the image is not reduced and the receiver is able to get the required information. Some attacks such as image cropping and salt & pepper noise, destroy the watermark’s information. In this article, a new watermarking scheme is proposed which is robust against salt & pepper noise and tough cropping. A Sudoku table comprises 9 regions, each row and column of the table contains different numbers from 1 to 9. In the proposed scheme, Sudoku table and both watermarking approaches based on spatial domain and transform domain are used. Robustness of watermarking against cropping attack is 86% and its robustness against salt and pepper noise is about 75%, which shows good and effective performance of the proposed scheme.
    Keywords: Digital Image Watermarking, Sudoku, Spatial domain, Transform domain, Cropping, Salt, Pepper Noise
  • Iraj Hadinejad, Asghar Fatemi Page 16
    Input of a Multiple Target Tracking (MTT) system is sensor''s detection data include of true and noise observations in tracking space. In MTT an important stage is data association which assigns true observations to the existed tracks. Multiple targets with heavy noise observations can increase the computational complexity and decrease the data association accuracy. Joint Probabilistic Data Association (JPDA) is a conventional algorithm for solving the association problems in the MTT. The JPDA method generates all the possible hypotheses of observation to track associations and their probabilities. Unfortunately, increase in the noise observations and track coalescence lead to the many generations of association hypotheses, complexity computations, low accuracy, slowing or even stopping the JPDA tracking process. In order to resolve this problem, a new method is proposed to improve the JPDA with eliminating the hypothesis’s generation step. The proposed method calculates the data association probabilities using parsing the hypothesis probability, instead of hypothesis generation. Simulation results show that the proposed method has good performance, accurate and fast for MTT in the presence of heavy noise observations.
    Keywords: Multiple Target Tracking, Probabilistic Data Association, Noise Observations, Tracking Precision
  • Farbayan Khordadpour Deylamani, Saeed Ghazi-Maghrebi Page 23
    Due to increasing demand of better performance in wireless communication systems, significance of using more robust transmission techniques against multipath and time variable channel distortion is increased. Although using multicarrier transmission schemes is not limited to recent years, the idea of utilizing Wavelet Packet Transform (WPT) as an alternative for Fast Fourier Transform (FFT) as the core of the multicarrier system is introduced in recent years. In this paper two different schemes of Orthogonal Frequency Division Multiplexing (OFDM) including FFT-based OFDM and WPT-based OFDM are introduced and their structures in different aspects and their performance over AWGN channel with different modulation mappings are investigated. Obtained results show better performance in WPT-OFDM systems.
    Keywords: Orthogonal Frequency Division Multiplexing scheme, WPT, based OFDM, FFT, based OFDM