Now showing items 13-24 of 123

    • New trends in image and video compression 

      Torres Urgell, Lluís (Eurasip, 2000)
      Conference report
      Open Access
      Image and video compression have been the object of intensive research in the last thirty years. The field is now mature as is proven by the large number of applications that make use of this technology. Digital Video ...
    • New receivers for DS-SS in time variant multipath channels based on the PN alignment concept 

      Socoro, J; Pijoan, J L; Moran, J A; Tarrés Ruiz, Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2000)
      Conference report
      Open Access
      We present new combined blind equalization and detection schemes for a DS-SS system. The new proposed algorithms improve the bit error rate compared to traditional RAKE receivers in time-variant channels with multipath. ...
    • A contribution to video coding using layers 

      Torres Urgell, Lluís; Lecha, M (1998)
      Conference report
      Open Access
      Layered representations of video sequences, originally introduced in [1], are important in several applications. Specifically, they are very appropriate for object tracking, object manipulation, content-based scalability ...
    • An experimental course on digital communications 

      Bertran Albertí, Eduardo; Tarrés Ruiz, Francisco; Montoro López, Gabriel (IEEE PRESS, 1998)
      Conference report
      Open Access
      In this paper a laboratory course on digital communications is presented. This course has been designed for medium degree professionals in the telecommunications field, and it is based on training equipment developed to ...
    • Second generation video coding schemes and their role in mpeg-4 

      Torres Urgell, Lluís; Pereira Marques, Fernando; Kunt, Murat (UNIVERSITÉ CATHOLIQUE DE LOUVAIN, 1996)
      Conference report
      Open Access
      Since its introduction in 1985, there has been a lot of activity in the eld of second generation still image coding. In the last years, the approach has been extended to video coding and has been the basis for European ...
    • Strong edge features for image coding 

      Casas Pla, Josep Ramon; Torres Urgell, Lluís (P. MARAGOS, R.W. SCHAFER KLUWER ACADEMIA PUBLISHERS, 1996)
      Conference report
      Open Access
      A two-component model is proposed for perceptual image coding. For the first component of the model, the watershed operator is used to detect strong edge features. Then, an efficient morphological interpolation algorithm ...
    • Prediction error image coding using a modified stochastic vector quantization scheme 

      Torres Urgell, Lluís; Casas Pla, Josep Ramon (IEEE, 1996)
      Conference report
      Open Access
      The objective of this paper is to provide an efficient and yet simple method to encode the prediction error image of video sequences, based on a stochastic vector quantization (SVQ) approach that has been modified to cope ...
    • An efficient technique of texture representation in segmentation-based image coding schemes 

      Torres Urgell, Lluís; Casas Pla, Josep Ramon; Campins, J (IEEE IEEE, 1995)
      Conference report
      Open Access
      In segmentation-based image coding techniques the image to be compressed is first segmented. Then, the information is coded describing the shape and the interior of the regions. A new method to encode the texture obtained ...
    • New approaches to texture coding in segmentation and feature-based image coding schemes 

      Torres Urgell, Lluís; Casas Pla, Josep Ramon (. S.N., 1995)
      Conference report
      Open Access
    • A new approach to texture coding using stochastic vector quantization 

      Gimeno, D; Torres Urgell, Lluís; Casas Pla, Josep Ramon (IEEE Computer Society, 1994)
      Conference report
      Open Access
      A new method for texture coding which combines 2-D linear prediction and stochastic vector quantization is presented in this paper. To encode a texture, a linear predictor is computed first. Next, a codebook following the ...
    • Segmentation based coding of textures using stochastic vector quantization 

      Torres Urgell, Lluís; Casas Pla, Josep Ramon; Diego, de S (1994)
      Conference report
      Open Access
      In second generation image compression techniques the image to be compressed is first segmented. The pixels are divided into mutually exclusive spatial regions based on some criteria. After segmentation, the image consists ...
    • Residual image coding using mathematical morphology 

      Casas Pla, Josep Ramon; Torres Urgell, Lluís (1994)
      Conference report
      Open Access
      A new method for the extraction, selection and coding of perceptually significant image components in a video sequence is presented. It has been applied to the coding residues of a segmentation-based multilevel coding ...