Now showing items 1-20 of 28

    • 3D model compression using connectivity-guided adaptive wavelet transform built into 2D SPIHT 

      Köse K.; Çetin, A. E.; Güdükbay U.; Onural, L. (Academic Press, 2010-01)
      Connectivity-Guided Adaptive Wavelet Transform based mesh compression framework is proposed. The transformation uses the connectivity information of the 3D model to exploit the inter-pixel correlations. Orthographic ...
    • Adaptive correction and look-up table based interpolation of quadrature encoder signals 

      Suhre, A.; Kose, K.; Cetin, A. E.; Gurcan, M.N. (2011)
      In this paper, an adaptive color transform for image compression is introduced. In each block of the image, coefficients of the color transform are determined from the previously compressed neighboring blocks using weighted ...
    • Adaptive polyphase subband decomposition structures for image compression 

      Gerek, Ö. N.; Çetin, A. E. (IEEE, 2000)
      Subband decomposition techniques have been extensively used for data coding and analysis. In most filter banks, the goal is to obtain subsampled signals corresponding to different spectral regions of the original data. ...
    • Binary morphological subband decomposition for image coding 

      Gurcan, M. N.; Gerek, O. N.; Cetin, A. E. (IEEE, Piscataway, NJ, United States, 1996)
      In this paper a binary waveform coding method based on morphological subband decomposition coupled with embedded zero-tree and entropy coding is described. This method can be utilized in text compression or bit-plane coding ...
    • Content-adaptive color transform for image compression 

      Suhre, A.; Kose, K.; Cetin, A. E.; Gurcan, M. N. (Institute of Electrical and Electronics Engineers, 2011-05-09)
      In this paper, an adaptive color transform for image compression is introduced. In each block of the image coefficients of the color transform are determined from the previously compressed neighboring blocks using weighted ...
    • DCT coding of nonrectangularly sampled images 

      Gündüzhan, E.; Çetin, A. E.; Tekalp, A. M. (IEEE, 1994)
      Discrete cosine transform (DCT) coding is widely used for compression of rectangularly sampled images. In this letter, we address efficient DCT coding of nonrectangularly sampled images. To this effect, we discuss an ...
    • Estimation of depth fields suitable for video compression based on 3-D structure and motion of objects 

      Alatan, A. A.; Onural, L. (Institute of Electrical and Electronics Engineers, 1998-06)
      Intensity prediction along motion trajectories removes temporal redundancy considerably in video compression algorithms. In three-dimensional (3-D) object-based video coding, both 3-D motion and depth values are required ...
    • An image watermarking algorithm via Zero Assigned Filter Banks 

      Yücel, Z.; Bülent Özgüler, A. (2005)
      In this paper a new method for digital image watermarking based on Zero Assigned Filter Banks and Embedded Zero Tree Wavelet (EZW) algorithm is presented. An image is partitioned into 128 × 128 subblocks and each block is ...
    • Joint estimation and optimum encoding of depth field for 3-D object-based video coding 

      Alatan, A.Aydin, Onural Levent (IEEE, Los Alamitos, CA, United States, 1996)
      3-D motion models can be used to remove temporal redundancy between image frames. For efficient encoding using 3-D motion information, apart from the 3-D motion parameters, a dense depth field must also be encoded to achieve ...
    • Key frame selection from MPEG video data 

      Gerek O.N.; Altunbasak, Y. (1997)
      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 ...
    • Linear/nonlinear adaptive polyphase subband decomposition structures for image compression 

      Gerek, Ö. N.; Çetin, A. E. (Institute of Electrical and Electronics Engineers, 1998)
      Subband decomposition techniques have been extensively used for data coding and analysis. In most filter banks, the goal is to obtain subsampled signals corresponding to different spectral bands of the original data. ...
    • Lossless image compression by LMS adaptive filter banks 

      Öktem, R.; Çetin, A. E.; Gerek, O. N.; Öktem, L.; Egiazarian, K. (Elsevier, 2001)
      A lossless image compression algorithm based on adaptive subband decomposition is proposed. The subband decomposition is achieved by a two-channel LMS adaptive filter bank. The resulting coefficients are lossy coded first, ...
    • Lossless image compression using an edge adapted lifting predictor 

      Gerek Ö.N.; Çetin, A.E. (2005)
      We present a novel and computationally simple prediction stage in a Daubechies 5/3 - like lifting structure for lossless image compression. In the 5/3 wavelet, the prediction filter predicts the value of an odd-indexed ...
    • Motion-compensated prediction based algorithm for medical image sequence compression 

      Oǧuz, S. H.; Gerek, Ö. N.; Çetin, A. E. (Elsevier BV, 1995-09)
      A method for irreversible compression of medical image sequences is described. The method relies on discrete cosine transform and motion-compensated prediction to reduce intra- and inter-frame redundancies in medical image ...
    • Moving region detection in compressed video 

      Töreyin, B. U.; Cetin, A. E.; Aksay, A.; Akhan, M. B. (Springer, 2004)
      In this paper, an algorithm for moving region detection in compressed video is developed. It is assumed that the video can be compressed either using the Discrete Cosine Transform (DOT) or the Wavelet Transform (WT). The ...
    • Moving region detection in wavelet compressed video 

      Töreyin, B.U.; Çetin, A.E.; Aksay, A.; Akhan, M.B. (2004)
      In many vision based surveillance systems the video is stored in wavelet compressed form. In this study, an algorithm for moving object and region detection in video that is compressed using a wavelet transform (WT) is ...
    • Multiresolution block coding method for visualization of compressed images in multimedia applications 

      Gerek, O. N.; Cetin, E. A. (Society of Photo-Optical Instrumentation Engineers, 1994)
      Multimedia and Picture Archiving and Communication System (PACS) applications require efficient ways of handling images for communication and visualization. In many Visual Information and Management Systems (VIMS), it may ...
    • Near-lossless image compression techniques 

      Ansari, R.; Memon, N.; Ceran, E. (S P I E - International Society for Optical Engineering, 1998)
      Predictive and multiresolution techniques for near- lossless image compression based on the criterion of maximum allowable deviation of pixel values are investigated. A procedure for near-lossless compression using a ...
    • Nonrectangular wavelets for multiresolution mesh analysis and compression 

      Köse K.; Çetin, A. E.; Güdükbay U.; Onural, L. (2006)
      We propose a new Set Partitioning In Hierarchical Trees (SPIHT) based mesh compression framework. The 3D mesh is first transformed to 2D images on a regular grid structure. Then, this image-like representation is wavelet ...
    • Novel methods for microscopic image processing, analysis, classification and compression 

      Suhre, Alexander (Bilkent University, 2013)
      Microscopic images are frequently used in medicine and molecular biology. Many interesting image processing problems arise after the initial data acquisition step, since image modalities are manifold. In this thesis, we ...