14,813 research outputs found

    Particle detection and tracking in fluorescence time-lapse imaging: a contrario approach

    Full text link
    This paper proposes a probabilistic approach for the detection and the tracking of particles in fluorescent time-lapse imaging. In the presence of a very noised and poor-quality data, particles and trajectories can be characterized by an a contrario model, that estimates the probability of observing the structures of interest in random data. This approach, first introduced in the modeling of human visual perception and then successfully applied in many image processing tasks, leads to algorithms that neither require a previous learning stage, nor a tedious parameter tuning and are very robust to noise. Comparative evaluations against a well-established baseline show that the proposed approach outperforms the state of the art.Comment: Published in Journal of Machine Vision and Application

    Data hiding using integer lifting wavelet transform and DNA computing

    Get PDF
    DNA computing widely used in encryption or hiding the data. Many researchers have proposed many developments of encryption and hiding algorithms based on DNA sequence to provide new algorithms. In this paper data hiding using integer lifting wavelet transform based on DNA computing is presented. The transform is applied on blue channel of the cover image. The DNA encoding used to encode the two most significant bits of LL sub-band. The produced DNA sequence used for two purpose, firstly, it use to construct the key for encryption the secret data and secondly to select the pixels in HL, LH, HH sub-bands for hiding in them. Many measurement parameters used to evaluate the performance of the proposed method such PSNR, MSE, and SSIM. The experimental results show high performance with respect to different embedding rate

    Improved methods and system for watermarking halftone images

    Get PDF
    Watermarking is becoming increasingly important for content control and authentication. Watermarking seamlessly embeds data in media that provide additional information about that media. Unfortunately, watermarking schemes that have been developed for continuous tone images cannot be directly applied to halftone images. Many of the existing watermarking methods require characteristics that are implicit in continuous tone images, but are absent from halftone images. With this in mind, it seems reasonable to develop watermarking techniques specific to halftones that are equipped to work in the binary image domain. In this thesis, existing techniques for halftone watermarking are reviewed and improvements are developed to increase performance and overcome their limitations. Post-halftone watermarking methods work on existing halftones. Data Hiding Cell Parity (DHCP) embeds data in the parity domain instead of individual pixels. Data Hiding Mask Toggling (DHMT) works by encoding two bits in the 2x2 neighborhood of a pseudorandom location. Dispersed Pseudorandom Generator (DPRG), on the other hand, is a preprocessing step that takes place before image halftoning. DPRG disperses the watermark embedding locations to achieve better visual results. Using the Modified Peak Signal-to-Noise Ratio (MPSNR) metric, the proposed techniques outperform existing methods by up to 5-20%, depending on the image type and method considered. Field programmable gate arrays (FPGAs) are ideal for solutions that require the flexibility of software, while retaining the performance of hardware. Using VHDL, an FPGA based halftone watermarking engine was designed and implemented for the Xilinx Virtex XCV300. This system was designed for watermarking pre-existing halftones and halftones obtained from grayscale images. This design utilizes 99% of the available FPGA resources and runs at 33 MHz. Such a design could be applied to a scanner or printer at the hardware level without adversely affecting performance

    Information Security Using DNA Sequences

    Get PDF
       يعد أمن المعلومات من المواضيع المهمة، ويرجع ذلك أساسًا إلى النمو الهائل في استخدام الإنترنت على مدى السنوات القليلة الماضية. نتيجة لهذا النمو، كانت هناك حالات وصول غير مصرح به، والتي تم تقليلها بفضل "استخدام مجموعة من بروتوكولات الاتصال الآمن، مثل التشفير وإخفاء البيانات". باستخدام القدرات الجزيئية الحيوية للحمض النووي، ازداد استخدام الحمض النووي كناقل للتشفير وإخفاء البيانات في السنوات الأخيرة. أثار إدراك أن الحمض النووي قد يعمل كوسيط نقل أثار هذه الحركة. في هذه الدراسة، نفحص أولاً ونلخص بإيجاز تطور نظام ترميز الحمض النووي الحالي. بعد ذلك، يتم تصنيف الطرق العديدة التي تم بها استخدام الحمض النووي لتحسين تقنيات التشفير. تمت مناقشة مزايا وعيوب هذه الخوارزميات وأحدث التطورات في تقنيات التشفير القائم على الحمض النووي. أخيرًا، نقدم أفكارنا حول المستقبل المحتمل لخوارزميات التشفير القائمة على الحمض النووي.Information security is a significant cause for concern, mainly because of the explosive growth in internet usage over the last few years. Due to this growth, there have been occurrences of unauthorized access, which have been reduced thanks to “using a range of secure communication protocols, such as encryption and data concealment”. Using DNA's bio-molecular capabilities, the usage of DNA as a carrier for encryption and data concealing has increased in recent years. The realization that DNA may function as a transport medium sparked this movement. In this study, we first examine and briefly outline the evolution of the present DNA coding system. After that, the several ways DNA has been used to enhance encryption techniques are categorized. The benefits and drawbacks of these algorithms and the most recent advancements in DNA-based encryption techniques are discussed. Finally, we provide our thoughts on the potential future of DNA-based encryption algorithms. &nbsp

    Spread spectrum-based video watermarking algorithms for copyright protection

    Get PDF
    Merged with duplicate record 10026.1/2263 on 14.03.2017 by CS (TIS)Digital technologies know an unprecedented expansion in the last years. The consumer can now benefit from hardware and software which was considered state-of-the-art several years ago. The advantages offered by the digital technologies are major but the same digital technology opens the door for unlimited piracy. Copying an analogue VCR tape was certainly possible and relatively easy, in spite of various forms of protection, but due to the analogue environment, the subsequent copies had an inherent loss in quality. This was a natural way of limiting the multiple copying of a video material. With digital technology, this barrier disappears, being possible to make as many copies as desired, without any loss in quality whatsoever. Digital watermarking is one of the best available tools for fighting this threat. The aim of the present work was to develop a digital watermarking system compliant with the recommendations drawn by the EBU, for video broadcast monitoring. Since the watermark can be inserted in either spatial domain or transform domain, this aspect was investigated and led to the conclusion that wavelet transform is one of the best solutions available. Since watermarking is not an easy task, especially considering the robustness under various attacks several techniques were employed in order to increase the capacity/robustness of the system: spread-spectrum and modulation techniques to cast the watermark, powerful error correction to protect the mark, human visual models to insert a robust mark and to ensure its invisibility. The combination of these methods led to a major improvement, but yet the system wasn't robust to several important geometrical attacks. In order to achieve this last milestone, the system uses two distinct watermarks: a spatial domain reference watermark and the main watermark embedded in the wavelet domain. By using this reference watermark and techniques specific to image registration, the system is able to determine the parameters of the attack and revert it. Once the attack was reverted, the main watermark is recovered. The final result is a high capacity, blind DWr-based video watermarking system, robust to a wide range of attacks.BBC Research & Developmen

    Information Hiding Based on DNA Sequences

    Get PDF
    يعد أمن المعلومات مصدر قلق رئيسي، خاصة في ضوء التوسع السريع في استخدام الإنترنت في السنوات الأخيرة. نتيجة لهذا التوسع، كانت هناك حالات وصول غير قانوني، والتي تم تخفيفها من خلال اعتماد مجموعة متنوعة من بروتوكولات الاتصال الآمن، بما في ذلك التشفير وإخفاء البيانات. في السنوات الأخيرة، كانت هناك زيادة في استخدام الحمض النووي للتشفير وإخفاء البيانات كناقل، مع الاستفادة من قدراته الجزيئية الحيوية. في إخفاء البيانات. نتيجة لذلك، في نهج إخفاء البيانات، يتم استخدام قواعد الحمض النووي كناقل للمعلومات لتعزيز الأمن. يندمج علم إخفاء المعلومات والتشفير المستند إلى الحمض النووي بين السمات البيولوجية والتقنيات التقليدية من أجل تحقيق خوارزمية مؤمنة جيدًا تستغلها. لذلك، توفر تسلسلات الحمض النووي قدرة عالية على البيانات بما في ذلك الحفاظ على الخصائص الكيميائية والبيولوجية لتسلسل الحمض النووي.Information security is a major source of worry, especially in light of the rapid expansion of internet use in recent years. As a result of this expansion, there have been incidences of illegal access, which have been mitigated by the adoption of a variety of secure communication protocols, including encryption and data concealment. DNA's bio-molecular properties have seen an uptick in popularity as a carrier for cryptography and data hiding in recent years. when information needs to be hidden. Therefore, DNA bases are utilized as information carriers in the data concealing strategy to increase safety. DNA-based steganography and cryptography combine a biological property with conventional methods to provide an algorithm with increased security. Because of their ability to maintain their chemical and biological characteristics, DNA sequences also have a high data capacity

    A Direct Construction of 2D-CCC with Arbitrary Array Size and Flexible Set Size Using Multivariable Function

    Full text link
    Recently, two-dimensional (2D) array codes have been found to have applications in wireless communication.In this paper, we propose direct construction of 2D complete complementary codes (2D-CCCs) with arbitrary array size and flexible set size using multivariable functions (MVF). The Peak-to-mean envelope power ratio (PMEPR) properties of row and column sequences of the constructed 2D-CCC arrays are investigated. The proposed construction generalizes many of the existing state-of-the-art such as Golay complementary pair (GCP), one-dimensional (1D)-CCC, 2D Golay complementary array set (2D-GCAS), and 2D-CCC with better parameters compared to the existing work
    corecore