IET Image Processing

Adaptive decimation (AD) is a technique that aims at compressing images with a very small amount of computations and memory requirement. For images that contain moderate amounts of textural content, the method exhibits satisfactory performance and in general provides good visual quality and acceptable coding fidelity at low bit-rate of around 0.2 bpp. Although the complexity of the method is relat... View full abstract»

A fast intra-prediction algorithm to determine the coding mode for 4 x 4 blocks is presented. The near pixel-correlation integration approach is proposed to compute the parameter for each mode along the predictive direction. The parameters that can be easily estimated with the simple computation are useful to represent the feature of block mode. On the basis of the fast algorithm, only three to fo... View full abstract»

The algorithms for multi-polarimetric synthetic aperture radar (SAR) intensity image compression are investigated. First, the multi-polarimetric SAR intensity images (HH, HV and VV) are considered as a 3D-matrix unit, and then a 3D-matrix transform is adopted to remove the redundancies, which includes ID discrete cosine transform (DCT) in the polarimetric channels and 2D discrete wavelet transform... View full abstract»

A new spatially adaptive wavelet-based method is introduced for reducing noise in images corrupted by additive white Gaussian noise. It is shown that a symmetric normal inverse Gaussian distribution is highly suitable for modelling the wavelet coefficients. In order to estimate the parameters of the distribution, a maximum- likelihood-based technique is proposed, wherein the Gauss-Hermite quadratu... View full abstract»

Fractal image coding is a block-based scheme that exploits the self-similarity hiding within an image. Fractal parameters generated by the block-based scheme are quantitative measurements of self-similarity, and therefore they can be used to construct image signatures. By combining fractal parameters and collage error, a set of new statistical fractal signatures, such as histogram of collage error... View full abstract»

Area openings and closings are basic connected morphological operators that remove connected components which fail an area criterion. They are widely used in image filtering (e.g. for noise reduction) and segmentation and can be implemented efficiently using union-find-based algorithms. The authors show that the computational complexity of morphological area openings/closings based on disjoint set... View full abstract»