Standard and specific compression techniques for DNA microarray images

We review the state of the art in DNA microarray image compression and provide original comparisons between standard and microarray-specific compression techniques that validate and expand previous work. First, we describe the most relevant approaches published in the literature and classify them according to the stage of the typical image compression process where each approach makes its contribution, and then we summarize the compression results reported for these microarray-specific image compression schemes. In a set of experiments conducted for this paper, we obtain new results for several popular image coding techniques that include the most recent coding standards. Prediction-based schemes CALIC and JPEG-LS are the best-performing standard compressors, but are improved upon by the best microarray-specific technique, Battiato's CNN-based scheme

Eina de control d'accés a la xarxa

L'eina de control d'accés a la xarxa que es proposa en aquest article, sorgeix de la mancança d'una plataforma de gestió pels tallafocs d'una organització. L'eina en qüestió pretén facilitar la gestió treballant d'una manera organitzada, com és agrupant les regles per grups i podent assignar aquests grups als servidors. D'aquesta manera, es té una plataforma on poder veure quines regles estan donades per cada màquina de l'organització. Aquesta eina utilitza una plataforma d'automatització per comunicar-se amb els servidors i poder així, introduir les regles adients a cada màquina. Fent-la així, una eina innovadora al món de la gestió remota dels tallafocsThe network access control tool proposed in this article, appears from the lack of a management platform for an organization's firewall. The tool in matter aims to facilitate management working in a organized way, like for instance putting together rules for groups and assign these groups to the servers. This way, there is a platform where you can see which rules are given for each organization machine. This tool uses an automation platform to communicate with the servers and to be able to enter the suitable rules to each machine, thus making it an innovative tool in remote management of firewall.La herramienta de control de acceso a la red que se propone en este artículo, surge de la carencia de una plataforma de gestión para los cortafuegos de una organización. La herramienta en cuestión pretende facilitar la gestión trabajando de una manera organizada, como es agrupando las reglas por grupos y pudiendo asignar estos grupos a los servidores. De esta manera, se tiene una plataforma donde se puede ver qué reglas están dadas para cada máquina de la organización. Esta herramienta utiliza una plataforma de automatización para comunicarse con los servidores y poder así, introducir las reglas adecuadas a cada máquina. Haciéndola así, una herramienta innovadora en el mundo de la gestión remota de los cortafuegos

Sistema de archivos remoto cifrado y de un solo archivo

El incremento en el uso de los servicios de almacenaje de datos en la nube, en los que el propietario de los datos guarda su información en los servidores de un tercero, resulta en un aumento del riesgo de que sus datos se vean comprometidos o manipulados. Almacenar datos en un medio no seguro es un problema que ya ha sido tratado con anterioridad en incontables ocasiones, e incluso si las partes principales necesarias para realizar este proyecto están al alcance de todos, no parece haber una solución disponible. El objetivo de este proyecto es el de diseñar y desarrollar una solución para mitigar este problema.The increasing use of cloud storage services, in which the data owners upload their files a third party's server, results in an increasing risk of this data getting compromised or manipulated. Storing data in a non secure medium is a problem that has been treated time and again, and although the primary necessary parts needed to implement a solution for this problem are available to everyone, we could not find a good solution for it. This project's goal is to design and develop a solution to mitigate this problem.L'increment en l'ús dels serveis d'emmagatzematge de dades al núvol, en els quals el propietari de les dades guarda la seva informació als servidors d'una tercera part, resulta en un increment del risc que les seves dades es vegin compromeses o manipulades. Emmagatzemar dades en un medi no segur és un problema que ja s'ha tratat amb anterioritat en incomptables ocasions, i tot i que les parts principals i necessàries per a realitzar aquest projecte són a l'abast de tothom, no hi ha cap solució disponible. L'objetiu d'aquest projecte és el de dissenyar i desenvolupar una solució per a mitigar aquest problema

A fully embedded two-stage coder for hyperspectral near-lossless compression

This letter proposes a near-lossless coder for hyperspectral images. The coding technique is fully embedded and minimizes the distortion in the l2 norm initially and in the l∞ norm subsequently. Based on a two-stage near-lossless compression scheme, it includes a lossy and a near-lossless layer. The novelties are: the observation of the convergence of the entropy of the residuals in the original domain and in the spectral-spatial transformed domain; and an embedded near-lossless layer. These contributions enable a progressive transmission while optimising both SNR and PAE performance. The embeddedness is accomplished by bitplane encoding plus arithmetic encoding. Experimental results suggest that the proposed method yields a highly competitive coding performance for hyperspectral images, outperforming multi-component JPEG2000 for l∞ norm and pairing its performance for l2 norm, and also outperforming M-CALIC in the near-lossless case -for PAE ≥5-

On the hardware implementation of the arithmetic elements of the pairwise orthogonal transform

The pairwise orthogonal transform (POT) is an attractive alternative to the Kahrunen-Loève transform for spectral decorrelation in on-board multispectral and hyperspectral image compression due to its reduced complexity. This work validates that the low complexity of the POT makes it feasible for a space-qualified field-programmable gate array (FPGA) implementation. A register transfer level description of the arithmetic elements of the POT is provided with the aim of achieving a low occupancy of resources and making it possible to synthesize the design on a space-qualified RTAX2000S and RTAX2000S-DSP. In order to accomplish these goals, the operations of the POT are fine-tuned such that their implementation footprint is minimized while providing equivalent coding performance. The most computationally demanding operations are solved by means of a lookup table. An additional contribution of this paper is a bit-exact description of the mathematical equations that are part of the transform, defined in such a way that they can be solved with integer arithmetic and implementations that can be easily cross-validated. Experimental results are presented, showing that it is feasible to implement the components of the POT on the mentioned FPGA

Lossless compression of color filter array mosaic images with visualization via JPEG 2000

Digital cameras have become ubiquitous for amateur and professional applications. The raw images captured by digital sensors typically take the form of color filter array (CFA) mosaic images, which must be "developed" (via digital signal processing) before they can be viewed. Photographers and scientists often repeat the "development process" using different parameters to obtain images suitable for different purposes. Since the development process is generally not invertible, it is commonly desirable to store the raw (or undeveloped) mosaic images indefinitely. Uncompressed mosaic image file sizes can be more than 30 times larger than those of developed images stored in JPEG format. Thus, data compression is of interest. Several compression methods for mosaic images have been proposed in the literature. However, they all require a custom decompressor followed by development-specific software to generate a displayable image. In this paper, a novel compression pipeline that removes these requirements is proposed. Specifically, mosaic images can be losslessly recovered from the resulting compressed files, and, more significantly, images can be directly viewed (decompressed and developed) using only a JPEG 2000 compliant image viewer. Experiments reveal that the proposed pipeline attains excellent visual quality, while providing compression performance competitive to that of state-of-the-art compression algorithms for mosaic images

Almost fixed quality rate-allocation under unequal scaling factors for on-board remote-sensing data compression

This article extends a rate-allocation method based on the near-lossless-rate (NLR) complexity that is designed to operate on-board spacecrafts, to include support for distortion scaling factors, such as those that are needed to code multi- and hyperspectral image when a spectral transform is employed. In this article, the conditions to achieve global minimum distortion are derived under the rate-distortion model based on the NLR complexity for the case of varying distortion scaling factors. Practical implementation issues are dealt with, and a rate-allocation method capable of operating under the constraints of on-board operation is provided. An exhaustive experimental validation of the rate-allocation method is performed, reporting modest performances for low rates and close to optimal performances for high rates

Performance impact of parameter tuning on the CCSDS-123.0-B-2 low-complexity lossless and near-lossless multispectral and Hyperspectral Image Compression standard

This article studies the performance impact related to different parameter choices for the new CCSDS-123.0-B-2 Low-Complexity Lossless and Near-Lossless Multispectral and Hyperspectral Image Compression standard. This standard supersedes CCSDS-123.0-B-1 and extends it by incorporating a new near-lossless compression capability, as well as other new features. This article studies the coding performance impact of different choices for the principal parameters of the new extensions, in addition to reviewing related parameter choices for existing features. Experimental results include data from 16 different instruments with varying detector types, image dimensions, number of spectral bands, bit depth, level of noise, level of calibration, and other image characteristics. Guidelines are provided on how to adjust the parameters in relation to their coding performance impact

Reducing data dependencies in the feedback loop of the CCSDS 123.0-B-2 predictor

Altres ajuts: European Space Agency (ESA) (Grant Number: 4000136723/22/NL/CRS)On-board multi- and hyperspectral instruments acquire large volumes of data that need to be processed with the limited computational and storage resources. In this context, the CCSDS 123.0-B-2 standard emerges as an interesting option to compress multi- and hyperspectral images on-board satellites, supporting both lossless and near-lossless compression with low complexity and reduced power consumption. Nonetheless, the inclusion of a feedback loop in the CCSDS 123.0-B-2 predictor to support near-lossless compression introduces significant data dependencies that hinder real-time processing, particularly due to the presence of a quantization stage within this loop. This work provides an analysis of the aforementioned data dependencies and proposes two strategies aiming at maximizing throughput in hardware implementations and thus enabling real-time processing. In particular, through an elaborate mathematical derivation, the quantization stage is removed completely from the feedback loop. This reduces the critical path, which allows for shorter initiation intervals in a pipelined hardware implementation and higher throughput. This is achieved without any impact in the compression performance, which is identical to the one obtained by the original data flow of the predictor

Performance impact of parameter tuning on the CCSDS-123 lossless multi- and hyperspectral image compression standard

Multispectral and hyperspectral image data payloads have large size and may be challenging to download from remote sensors. To alleviate this problem, such images can be effectively compressed using specially designed algorithms. The new CCSDS-123 standard has been developed to address onboard lossless coding of multispectral and hyperspectral images. The Standard is based on the Fast Lossless (FL) algorithm, which is composed of a causal context-based prediction stage and an entropy-coding stage that utilizes Golomb power-of-two codes. Several parts of each of these two stages have adjustable parameters. CCSDS-123 provides satisfactory performance for a wide set of imagery acquired by various sensors, but end-users of a CCSDS-123 implementation may require assistance to select a suitable combination of parameters for a specific application scenario. To assist end-users, this paper investigates the performance of CCSDS-123 under different parameter combinations and addresses the selection of an adequate combination given a specific sensor. Experimental results suggest that prediction parameters have a greater impact on the compression performance than entropy-coding parameters