Your browser does not support JavaScript!
http://iet.metastore.ingenta.com
1887
banner image
image of Volume 3, Issue 1
Online ISSN 1751-9667 Print ISSN 1751-9659

IET Image Processing

Volume 3, Issue 1, February 2009

Volumes & issues:

Volume 3, Issue 1

February 2009

Show / Hide details

    • Real-time implementation of order-statistics-based directional filters
      • Author(s): M. Emre Celebi
      • Source: IET Image Processing, Volume 3, Issue 1, p. 1 –9
      • DOI:  10.1049/iet-ipr:20080080
      • Type: Article
      • + Show details - Hide details
      • p. 1 –9 (9)
        Vector filters based on order-statistics have proved successful in removing impulsive noise from colour images while preserving edges and fine image details. Among these filters, the ones that involve the cosine distance function (directional filters) have particularly high computational requirements, which limits their use in time-critical applications. In this paper, we introduce two methods to speed up these filters. Experiments on a diverse set of colour images show that the proposed methods provide substantial computational gains without significant loss of accuracy.
        Add to favourites
        Export citations
      Probabilistic relevance feedback approach for content-based image retrieval based on gaussian mixture models
      • Author(s): A. Marakakis ; N. Galatsanos ; A. Likas ; A. Stafylopatis
      • Source: IET Image Processing, Volume 3, Issue 1, p. 10 –25
      • DOI:  10.1049/iet-ipr:20080012
      • Type: Article
      • + Show details - Hide details
      • p. 10 –25 (16)
        A new relevance feedback (RF) approach for content-based image retrieval is presented. This approach uses Gaussian mixture (GM) models of the image features and a query that is updated in a probabilistic manner. This update reflects the preferences of the user and is based on the models of both the positive and negative feedback images. The retrieval is based on a recently proposed distance measure between probability density functions, which can be computed in closed form for GM models. The proposed approach takes advantage of the form of this distance measure and updates it very efficiently based on the models of the user-specified relevant and irrelevant images. It is also shown that this RF framework is fairly general and can be applied in case other image models or distance measures are used instead of those proposed in this work. Finally, comparative numerical experiments are provided, which that demonstrate the merits of the proposed RF methodology and the use of the distance measure, and also the advantages of using GMs for image modelling.
        Add to favourites
        Export citations
      Rate control algorithm based on intra-picture complexity for H.264/AVC
      • Author(s): G.G. Lee ; H.-Y. Lin ; M.-J. Wang
      • Source: IET Image Processing, Volume 3, Issue 1, p. 26 –39
      • DOI:  10.1049/iet-ipr:20080088
      • Type: Article
      • + Show details - Hide details
      • p. 26 –39 (14)
        An efficient rate control algorithm based on the content-adaptive initial quantisation parameter (QP) setting scheme and the peak signal-to-noise ratio (PSNR) variation-limited bit-allocation strategy for low-complexity mobile applications is presented. This algorithm can efficiently measure the residual complexity of intra-pictures without performing the computation-intensive intra-prediction and mode decision in H.264/AVC, based on the structural and statistical features of local textures. This can adaptively set proper initial QP values for versatile video contents. In addition, this bit-allocation strategy can effectively distribute bit-rate budgets based on the monotonic property to enhance overall coding efficiency while maintaining the consistency of visual quality by limiting the variation of quantisation distortion. The experimental results reveal that the proposed algorithm surpasses the conventional rate control approaches in terms of the average PSNR from 0.34 to 0.95 dB. Moreover, this algorithm provides more impressive visual quality and more robust buffer controllability when compared with other algorithms.
        Add to favourites
        Export citations

Most viewed content for this Journal

Article
content/journals/iet-ipr
Journal
5
Loading

Most cited content for this Journal

Print this page
This is a required field
Please enter a valid email address