Initiation Into Research Fondecyt Project: Optimal packetization of still images in wireless vision sensor networks


Wireless visual sensor networks (WVSNs) represent a technological challenge that multiplies the difficulties of the well known classical wireless sensor networks (WSNs) applications. Considering the resource-constrained nature of current sensor nodes, the large amount of data necessary to code a single image increases the necessity of highly efficient processing and transmission algorithms. In this matter, significant progress has been made in the design of efficient algorithms for image or video compression, e.g., by reducing the computational complexity required to calculate a classic DCT . Other works point to the improvement of communication protocols. Nevertheless, many works put aside one of the most inherent issues in WSNs: packet loss.

The problem of packet losses can be addressed whether through the use of ARQ or FEC-based protocols, but at the expense of additional energy consumptions and latency. Luckily, in the case of still images data have a high loss-tolerance due to the correlation between neighboring pixels. This feature is widely exploited by lossy compression algorithms, but it can also be exploited to reinforce a transmission scheme. One of the simplest techniques for image robust transmission is block interleaving.

The effectiveness of the application of interleaving methods is assumed. However, methods are generic and the choice of the correct parameters is arbitrary. Also, there is no basis for comparison, not knowing a standard optimum to reach when designing an interleaving method. Characteristics of the channel, batteries level and images (among other factors) are also not considered.

In this project, we address the issue of block interleaving techniques studying the possibility of finding optimal interleaving configurations and to numerically evaluate existing and future proposals. We will focus on five problems. First, we will study error concealment and image quality metrics the more used in current image processing.
Second, we will rigorous study block interleaving methods, analyzing blocks' paths and parameters impact through extensive simulations. MPI and CUDA based programming will be applied. Simulations must consider multiple image sets and loss patterns. Comparisons, including image quality of reconstructed images and computing cost, will be provided.
Third, we will propose one (or various) objective functions, being a representative reference for evaluating the performances of an interleaving method. Thus, researchers will be able to estimate and compare the efficiency of interleaving methods without the necessity of making extensive simulations (what is mandatory for evaluations, until now). The idea is to count on a statistically-representative objective function to maximize (or minimize), whose validity will be supported with comparisons with our extensive simulations.
Fourth, by using the proposed objective function, we will find optimal parameters for existing interleaving methods, to finally (Fifth) work on an optimal reference interleaving configuration. Considering the proposed function, to find optimal (or pseudo-optimal) configurations which can serve as a comparison reference for more traditional interleaving methods. In this way, authors working on interleaving methods will know if their proposals are near a reference optimal.


The general goals of this research project are to propose a correct optimization function for the evaluation of block interleaving techniques and to find optimal configurations of coded/non-coded bitmaps, using the optimization function, to serve as a basis of reference for further proposals on the matter.

Specific goals of this project are:
  1. To analyze interleaving methods by performing extensive simulations using parallel programming with MPI and CUDA. Simulations must be performed over big sets of images and loss patterns.
  2. To establish an objective function allowing the evaluation of interleaving methods without the necessity of perform extensive simulations and to prove that this objective function is statistically representative.
  3. To study, with the proposed objective function, interleaving methods in the bibliography, finding optimal parameters to each of them.
  4. To find optimal bitmap configurations, in order to count on a comparison reference on the design of interleaving methods.


The adopted methodology will consider the following general steps:

  1. Extensive analysis of the literature, defining the state-of-the-art in the matter of interleaving methods for robust image communication, with special attention to works applied to wireless vision sensor networks.
  2. Preparation of a simulation testbed considering large sets of different images and loss patterns. Open-source application Sim-LIT will be used as basis for software application. The simulations of this project should be executed in a high-performance computer using parallel-programming with MPI libraries CUDA.
  3. Formal modeling of possible objective functions. Objective functions will be used with studied interleaving methods with multiple parameters. Resulting evaluation metrics will be stored and then compared with results of simulation for same interleaving methods with same parameters. Statistical metrics will determine if results of the proposed objective functions and simulations are correlated and if they can be used to replace extensive simulations for evaluation and compare.
  4. To use selected objective functions to evaluate literature's interleaving methods and to find optimal parameters for various image resolutions and/or characteristics.
  5. To find optimal interleaved bitmaps, using the selected objective functions, using genetic algorithms, simulated-annealing, and other search algorithms. Then, to compare optimal values obtained from previous applications and to compare with optimal bitmaps in order to find out if optimal bitmaps are better or (at least) equal to them.
Results of followed steps will be constantly documented. It is expected that this documentation becomes basis for publications in research journals and national/international conferences.

During the development of the present project, it is expected to share results and keep research discussions with Dr. Vincent Lecuire, from the Research Centre for Automatic Control of Nancy (CRAN), France.

In terms of the use of computing resources, all of the development and documentation will be carried out with open software, mainly based on distributions of the operating system GNU Linux and C++-based programming. All of the developed software will be correctly documented and codes published for open access to research community.

Project documentation will be written in LaTeX and there will be a database with documentation and reference will be registered in a .bib file. All of the results will be always stored in separated files with resumed explanations and reconstructed images correctly labeled with significant names.



  1. Katherine Zapata-Quiñones, Cristian Duran-Faundez, and Gilberto Gutiérrez. "Algoritmo Genético para la Generación de Configuraciones Óptimas de Paquetización de Imágenes". In: XXVII Encuentro Chileno de Computación (ECC 2015), Santiago, Chile, November, 2015. [slides (pdf | sp)]
  2. Joaquin Alder Silva-Faundez, Cristian Duran-Faundez, Pedro Melin, and Cristhian Aguilera. "An anticipatory control for a flexible manufacturing system based on the perception of mobile units using wireless sensor networks". In: International Journal of Computer, Communications & Control, 2015, 10(5), 702-717. DOI:
  3. Cristian Duran-Faundez, Jonathan Matías Palma Olate, Eric Orellana-Romero, and Pedro E. Melin. Effect of packet sampling time on a colony of mobile routing robots for communication link maintenance using IEEE 802.15.4 devices. In: 10th International Conference on MOdeling, Optimization and SIMlation (MOSIM 2014), Nancy, France, November 2014.
  4. Eric Orellana-Romero, Javier SanMartin-Hernandez, Cristian Duran-Faundez, Vincent Lecuire, and Katherine Zapata-Quinones. Evaluation of Block Interleaving Techniques for Robust Image Communication in Wireless Camera Sensor Networks. In: 2014 IEEE Conference on Wireless Sensors (ICWiSe 2014), Kuala Lumpur, Malaysia, October 2014.


Financial support


Last modified: Mar-28-2016