18,043 research outputs found
Model for Estimation of Bounds in Digital Coding of Seabed Images
This paper proposes the novel model for estimation of bounds in digital coding of images. Entropy coding of images is exploited to measure the useful information content of the data. The bit rate achieved by reversible compression using the rate-distortion theory approach takes into account the contribution of the observation noise and the intrinsic information of hypothetical noise-free image. Assuming the Laplacian probability density function of the quantizer input signal, SQNR gains are calculated for image predictive coding system with non-adaptive quantizer for white and correlated noise, respectively. The proposed model is evaluated on seabed images. However, model presented in this paper can be applied to any signal with Laplacian distribution
Symbolic local information transfer
Recently, the permutation-information theoretic approach has been used in a
broad range of research fields. In particular, in the study of highdimensional
dynamical systems, it has been shown that this approach can be effective in
characterizing global properties, including the complexity of their
spatiotemporal dynamics. Here, we show that this approach can also be applied
to reveal local spatiotemporal profiles of distributed computations existing at
each spatiotemporal point in the system. J. T. Lizier et al. have recently
introduced the concept of local information dynamics, which consists of
information storage, transfer, and modification. This concept has been
intensively studied with regard to cellular automata, and has provided
quantitative evidence of several characteristic behaviors observed in the
system. In this paper, by focusing on the local information transfer, we
demonstrate that the application of the permutation-information theoretic
approach, which introduces natural symbolization methods, makes the concept
easily extendible to systems that have continuous states. We propose measures
called symbolic local transfer entropies, and apply these measures to two test
models, the coupled map lattice (CML) system and the Bak-Sneppen model
(BS-model), to show their relevance to spatiotemporal systems that have
continuous states.Comment: 20 pages, 7 figure
Positional information, positional error, and read-out precision in morphogenesis: a mathematical framework
The concept of positional information is central to our understanding of how
cells in a multicellular structure determine their developmental fates.
Nevertheless, positional information has neither been defined mathematically
nor quantified in a principled way. Here we provide an information-theoretic
definition in the context of developmental gene expression patterns and examine
which features of expression patterns increase or decrease positional
information. We connect positional information with the concept of positional
error and develop tools to directly measure information and error from
experimental data. We illustrate our framework for the case of gap gene
expression patterns in the early Drosophila embryo and show how information
that is distributed among only four genes is sufficient to determine
developmental fates with single cell resolution. Our approach can be
generalized to a variety of different model systems; procedures and examples
are discussed in detail
Detection thresholding using mutual information
In this paper, we introduce a novel non-parametric thresholding method that we term Mutual-Information
Thresholding. In our approach, we choose the two detection thresholds for two input signals such that the
mutual information between the thresholded signals is maximised. Two efficient algorithms implementing our
idea are presented: one using dynamic programming to fully explore the quantised search space and the other
method using the Simplex algorithm to perform gradient ascent to significantly speed up the search, under the
assumption of surface convexity. We demonstrate the effectiveness of our approach in foreground detection
(using multi-modal data) and as a component in a person detection system
- …