Now showing items 1-20 of 33

    • Cepstrum based feature extraction method for fungus detection 

      Yorulmaz, Onur; Pearson, T.C.; Çetin, A. Enis (SPIE, 2011)
      In this paper, a method for detection of popcorn kernels infected by a fungus is developed using image processing. The method is based on two dimensional (2D) mel and Mellin-cepstrum computation from popcorn kernel images. ...
    • Compression of images in CFA format 

      Cüce, Halil İbrahim; Çetin, Ahmet Enis; Davey, M. K. (IEEE, 2006)
      In this paper, images in Color Filter Array (CFA) format are compressed without converting them to full-RGB color images. Green pixels are extracted from the CFA image data and placed in a rectangular array, and compressed ...
    • Current research activities on holographic video displays 

      Onural, L.; Yaraş, F.; Kang, H. (S P I E - International Society for Optical Engineering, 2010)
      "True 3D" display technologies target replication of physical volume light distributions. Holography is a promising true 3D technique. Widespread utilization of holographic 3D video displays is hindered by current technological ...
    • Degrees of freedom of optical systems and signals with applications to sampling and system simulation 

      Oktem F.S.; Özaktaş, Haldun M. (Optical Society of America, 2013)
      We study the degrees of freedom of optical systems and signals based on space-frequency (phase space) analysis. At the heart of this study is the relationship of the linear canonical transform domains to the space-frequency ...
    • Detection of microcalcifications in mammograms using nonlinear subband decomposition and outlier labeling 

      Gürcan, M. Nafi; Yardımcı, Yasemin C.; Çetin, A. Enis; Ansari, R. (SPIE, 1997-02)
      Computer-aided diagnosis will be an important feature of the next generation picture archiving and communication systems. In this paper, computer-aided detection of microcalcifications in mammograms using a nonlinear subband ...
    • Enhancement of images corrupted with signal dependent noise: Application to ultrasonic imaging 

      Kutay, M. Alper; Karaman, Mustafa; Bozdağı, Gözde (1993-11)
      An adaptive filter for smoothing images corrupted by signal dependent noise is presented. The filter is mainly developed for speckle suppression in medical B-scan ultrasonic imaging. The filter is based on mean filtering ...
    • Fast and accurate algorithms for quadratic phase integrals in optics and signal processing 

      Koç, A.; Özaktaş, Haldun M.; Hesselink L. (SPIE, 2011)
      The class of two-dimensional non-separable linear canonical transforms is the most general family of linear canonical transforms, which are important in both signal/image processing and optics. Application areas include ...
    • Feature issue of digital holography and 3D imaging (DH) introduction 

      Hayasaki, Y.; Zhou, C.; Popescu, G.; Onural, Levent (Optical Society of America (OSA), 2014-07)
      The OSA Topical Meeting "Digital Holography and 3D Imaging (DH)," was held in Seattle, Washington, July 13-17, 2014. Feature issues based on the DH meeting series have been released by Applied Optics (AO) since 2007. This ...
    • Fractional free space, fractional lenses, and fractional imaging systems 

      Sümbül, U.; Ozaktas, H. M. (OSA - The Optical Society, 2003)
      Continuum extensions of common dual pairs of operators are presented and consolidated, based on the fractional Fourier transform. In particular, the fractional chirp multiplication, fractional chirp convolution, and ...
    • Holographic 3DTV research within the European 3DTV project 

      Onural, Levent (Optical Society of America, 2008)
      A European project on 3DTV has been functional since September 2004. Holographic displays for 3DTV and signal processing issues associated with diffraction and holography are among research interests. The research has ...
    • Human face detection in video using edge projections 

      Türkan, M.; Dülek, B.; Onaran I.; Çetin, A.E. (2006)
      In this paper, a human face detection method in images and video is presented. After determining possible face candidate regions using color information, each region is filtered by a high-pass filter of a wavelet transform. ...
    • Integral imaging using phase-only LCoS spatial light modulators as Fresnel lenslet arrays 

      Ÿontem, A. O.; Onural, L. (Optical Society of Amercia, 2011-10-27)
      We present a digital integral imaging system. A Fresnel lenslet array pattern is written on a phase-only LCoS spatial light modulator device (SLM) to replace the regular analog lenslet array in a conventional integral ...
    • Kadastral haritalarin görüntü işleme teknikleri kullanilarak vektörizasyonu 

      Balkoca, A.; Yergök, Ahsen İkbal; Yücekaya, S. (IEEE, 2011-04)
      This study aims vectorizing cadastral maps by using image processing techniques. Firstly, landing marks on cadastral maps are found by Moore Neighbor Tracing method then the connections are extracted and connecting lines ...
    • Key frame selection from MPEG video data 

      Gerek, Ömer. N.; Altunbaşak, Y. (SPIE, 1997-02)
      This paper describes a method for selecting key frames by using a number of parameters extracted from the MPEG video stream. The parameters are directly extracted from the compressed video stream without decompression. A ...
    • Man-made object classification in SAR images using 2-D cepstrum 

      Eryildirim, A.; Çetin, A. Enis (IEEE, 2009-05)
      In this paper, a novel descriptive feature parameter extraction method from Synthetic Aperture Radar (SAR) images is proposed. The new method is based on the two-dimensional (2-D) real cepstrum. This novel 2-D cepstrum ...
    • Mel-cepstral methods for image feature extraction 

      Çakır, Serdar; Çetin, A. Enis (IEEE, 2010)
      A feature extraction method based on two-dimensional (2D) mel-cepstrum is introduced. The concept of one-dimensional (1D) mel-cepstrum which is widely used in speech recognition is extended to 2D in this article. Feature ...
    • Microwave imaging of three-dimensional conducting objects using the newton minimization approach 

      Etminan, A.; Gürel, L. (IEEE, 2013)
      In this work, we present a framework to detect the shape of unknown perfect electric conducting objects by using inverse scattering and microwave imaging. The initialguess object, which evolves to achieve the target, is ...
    • Object rigidity and reflectivity identification based on motion analysis 

      Zang, D.; Schrater P.R.; Doerschner, Katja (IEEE, 2010)
      Rigidity and reflectivity are important properties of objects, identifying these properties is a fundamental problem for many computer vision applications like motion and tracking. In this paper, we extend our previous ...
    • An overview of research in 3DTV 

      Onural, Levent (IEEE, 2007)
      3DTV is regarded by the experts and the general public as the next major step in video technologies. The ghost-like images of remote persons or objects are already depicted in many futuristic movies; both entertainment ...
    • Processing of optically-captured digital holograms for three-dimensional display 

      Naughton, T.J.; Kreis, T.; Onural, Levent; Ferraro, P.; Depeursinge, C.; Emery, Y.; Hennelly, B. M.; Kujawiñska, M. (2009-04)
      In digital holography, holograms are usually optically captured and then two-dimensional slices of the reconstruction volume are reconstructed by computer and displayed on a two-dimensional display. When the recording is ...