IEE Proceedings - Vision, Image and Signal Processing

In order to implement morphological filters on image processing systems. The size of the structuring element must be small due to the architectural constraints of the systems. The decomposition of the structuring element is required for filters with large structuring elements. An algorithm for the decomposition of an arbitrary 4-connected binary structuring element is developed which enables sub-o... View full abstract»

The authors present the nonlinear LMS adaptive filtering algorithm based on the discrete nonlinear Wiener (1942) model for second-order Volterra system identification application. The main approach is to perform a complete orthogonalisation procedure on the truncated Volterra series. This allows the use of the LMS adaptive linear filtering algorithm for calculating all the coefficients with effici... View full abstract»

The paper shows that the type-II r-dimensional discrete cosine transform (rD-DCT-II) of size ql1×ql2x...xq l1, where r>1 and q is an odd prime number, can be converted into a series of one-dimensional reduced DCT-IIs by using the polynomial transform. The number of multiplications for computing an rD-DCT-II is significantly reduced compared to that needed ... View full abstract»

A comparison between two fully parallel thinning algorithms designed for images sampled on the square and hexagonal grids is reported. Using techniques from mathematical morphology, a hexagonal algorithm has been designed to closely match the operation of a well known square grid algorithm. Proofs of the connectivity and the single pixel limb width of the resulting converged hexagonal skeleton hav... View full abstract»

Surface topography of the mixed cross-correlation and constant modulus algorithm (CC-CMA) is undertaken to provide a suitable range for the mixing parameter to avoid ill-convergence. Previous work indicated that the mixing parameter k should be chosen to be greater than 4/3, but this result was based upon an assumption of perfect equalisation of previous equaliser outputs. The authors relax this p... View full abstract»

Current techniques for road-traffic monitoring rely on sensors that have limited capabilities and are often both costly and disruptive to install. The use of video cameras (many of which are already installed to survey road networks), coupled with computer vision techniques, offers an attractive alternative to current sensors. Vision-based sensors have the potential to measure a greater variety of... View full abstract»

A novel approach called `VQ-agglomeration' capable of performing fast and autonomous clustering is presented. The approach involves a vector quantisation (VQ) process followed by an agglomeration algorithm that treats codewords as initial prototypes. Each codeword is associated with a gravisphere that has a well defined attraction radius. The agglomeration algorithm requires that each codeword be ... View full abstract»

The operational capacity of a watermark data channel is deduced by examining the correlation distribution at the retrieval end of a spread-spectrum-based watermarking system. This enables capacity to be determined given MPEG-2 compression, geometric attack, visual thresholds and channel coding. Watermarking itself is carried out in the DCT domain using video-dependent and visual perception concept... View full abstract»

The paper introduces a method of transmitting error resilient SPIHT coded images over highly error prone Rayleigh fading channels. First, the source significance of the SPIHT coded output is obtained. Based on the significance of the bits, the channel coding is varied accordingly. Channel coding consists of a mixture of rate compatible punctured convolutional (RCPC) codes and interleaving to comba... View full abstract»

The analytically continued Fourier transform of a two-dimensional image vanishes to zero on a two-dimensional surface embedded in a four-dimensional space. This surface uniquely characteristics the image and is known as a `zero sheet'. Since the manipulation of a function in four-dimensional space is cumbersome, the projections of zero sheets, known as `zero tracks' are calculated. This knowledge ... View full abstract»

The quality of 3-D reconstructions with multi-camera acquisition systems is strongly influenced by the accuracy of the camera calibration procedure. In fact, when acquiring a long sequence of views, mechanical shocks, vibrations and thermal gradients could cause a significant drift of the camera parameters. The authors propose a method for tracking the camera parameters and, whenever possible, cor... View full abstract»