Yazar "Yalman, Y." seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim Yok
    Öğe
    A high-capacity reversible data hiding method: HCRHide
    (Taylor & Francis Ltd, 2014) Yalman, Y.; Akar, F.
    Reversible data hiding methods have drawn considerable attention in the last decade, which allow full recovery of the original image used for embedding secret data as well as avert the third parties who should not realise the existence of hidden data. In this paper, we propose a highcapacity reversible data hiding method called HCRHide based on the Neighbour Mean Interpolation (NMI) method and the R-weighted Coding Method (RCM). Throughout a joint imperceptibility and data hiding capacity evaluation, results have approved high performance of the proposed method over the existing reversible data hiding methods.
  • Küçük Resim Yok
    Öğe
    A New DCT Based Watermarking Method Using Luminance Component
    (Kaunas Univ Technology, 2013) Yesilyurt, M.; Yalman, Y.; Ozcerit, A. T.
    The main purpose of the digital watermarking is to provide information security and copyright protection. From this point of view, a robust blind watermarking method based on Discrete Cosine Transform for colour images is proposed in this paper. The proposed method provides hiding a binary watermark in a compressed Digital Colour Image. First, the Digital Color Image is transformed into YCbCr from RGB color space and then the Discrete Cosine Transform middle band of the luminance (Y) component is used for watermarking processes. Each bit of the binary watermark is embedded in a different Discrete Cosine Transform block. Thus, deterioration on the image is minimized achieving high invisibility. The situation is checked whether the watermark is lost after the image saved. If the watermark is lost in any block, the average of some neighbouring Discrete Cosine Transform coefficients is used for embedding the watermark bit. The experimental results show that the proposed method can be safely used when point of interest is binary watermarks. Moreover, extraction processes do not need the cover image and the watermark is recovered completely. Statistical and perceptual quality evaluations show that the proposed method is better than its counterparts.
  • Küçük Resim Yok
    Öğe
    A web-based digital analysis interface for image quality assessment
    (Taylor & Francis Ltd, 2014) Yalman, Y.; Akar, F.; Bayilmis, C.
    Image processing and transmission systems may introduce some amount of distortion or artefacts in a digital image. This fact usually leads to a visual or statistical image quality assessment (IQA) required in many applications and research studies in order to analyse a product image in terms of deteriorations as well as effects of the processing. There are numerous IQA criteria presented in the literature separately that makes it really difficult both for use in comparative analyses and for educational purposes. In this presented work, a user friendly webbased digital educational interface for full-reference or no-reference image quality assessment using MATLAB builder NE has been developed. In addition to this, developed system performs user-defined optional deteriorations (median noise, Gaussian blur, motion blur, high-pass filter and jpeg compression) on the image and assesses deterioration of the image. It is an extremely easy, fast and economical way of analysing digital images, especially designed for researchers, graduate and postgraduate students who work on digital image processing. Using this webbased tool well contributes to teaching all of the IQA methods and quality effects of systematic distortions on the image as well as establishes a scientific benchmark for researchers.