Fractal image compression with region-based functionality

Abstract

Region-based functionality offered by the MPEG-4 video compression standard is also appealing for still images, for example to permit object-based queries of a still-image database. A popular method for still-image compression is fractal coding. However, traditional fractal image coding uses rectangular range and domain blocks. Although new schemes have been proposed that merge small blocks into irregular shapes, the merging process does not, in general, produce semantically-meaningful regions. We propose a new approach to fractal image coding that permits region-based functionalities; images are coded region by region according to a previously-computed segmentation map. We use rectangular range and domain blocks, but divide boundary blocks into segments belonging to different regions. Since this prevents the use of standard dissimilarity measure, we propose a new measure adapted to segment shape. We propose two approaches: one in the spatial and one in the transform domain. While providing additional functionality, the proposed methods perform similarly to other tested methods in terms of PSNR but often result in images that are subjectively better. Due to the limited domain-block codebook size, the new methods are faster than other fractal coding methods tested. The results are very encouraging and show the potential of this approach for various internet and still-image database applications.

Anisotropic Diffusive Transport in Annulus Fibrosus: Experimental Determination of the Diffusion Tensor by FRAP Technique

“…(6), one can obtain D(n) which depends on the choice of the frequencies u and v (or n), see Eq. (4). For this orthotropic diffusion case, it can be shown that the mean value of D(n) [averaged over the entire frequency space (u,v)] is given as follows:…”

A Review on Block Matching Motion Estimation and Automata Theory based Approaches for Fractal Coding

“…Franco and Mala [19] presented an algorithm for adaptive image partitioning achieving designated rates under a computational complexity constraint. Wang [20] proposed a graph based image segmentation algorithm used to divide the image into the different logical area and each logical area is coded into adaptive threshold quadtree partitioning approach.…”

“…The adaptive partition [68] and the hybrid compression algorithm exhibit, relatively, the high compression ratio for image [68] and the video conference sequences [67]. In conclusion, a fractal image codec performs better in terms of very fast decoding process as well as the promise of potentially good compression [69][70][71][72][73]. But at present, the fractal codec is not standardized because of its huge calculation amount and slow coding speed.…”

A novel fractal monocular and stereo video codec with object-based functionality

“…The object-based approach can also provide more natural representations of the scene and has another potential benefit of acquiring the depth information of semantically meaningful objects. In such a scheme, a prior segmentation map (alpha plane) of the image, which segments the image into objects, is known in advance [13,14].…”