Fabio Vega

Image encryption based on convolution operation in the gyrator transform domain

Recently, the gyrator transform (GT), which is also a kind of linear canonical transform (LCT), has been researched in the fields of image processing, mathematics and optics; the calculation of discrete GT can be implemented by Fresnel diffraction integral in free space under paraxial approximation; in this paper The expression of gyrator transform (GT) is rewritten by using convolution operation, from which GT can be composed of phase-only filtering, Fourier transform and inverse Fourier transform. We investigate an algorithm computing discrete GT by simulating the convolution expression of fractional Fourier transform. Some simulations in order to evaluate the difference between inverse transformed image and original image are presented to demonstrate the validity of the algorithm, the reversibility of numerical algorithm of transform is important to the field of optical information processing, such as image encryption, filtering and correlation.

System of acquisition and processing of images of dynamic speckle

In this paper we show the design and implementation of a system to capture and analysis of dynamic speckle. The device consists of a USB camera, an isolated system lights for imaging, a laser pointer 633 nm 10 mw as coherent light source, a diffuser and a laptop for processing video. The equipment enables the acquisition and storage of video, also calculated of different descriptors of statistical analysis (vector global accumulation of activity, activity matrix accumulation, cross-correlation vector, autocorrelation coefficient, matrix Fujji etc.). The equipment is designed so that it can be taken directly to the site where the sample for biological study and is currently being used in research projects within the group.

Simple method of fabrication tapered fiber

This paper presents a simple method for manufacturing fiber tapered through elongation, by the combination of heating with a butane torch and controlled stretch. Reducing the diameter of the multimode fiber of 100 microns to 10 microns, the displacement of the fiber is performed through bipolar stepping motors with one driver L293B and one PIC16F628A microcontroller for controlling movement. The system allows control of the desired fiber diameter up to 10 microns; the results are seen in a microscope and a rule of separation 2.5μm micrometer to calculate the diameter of the fiber.

Fingerprint verification by correlation using wavelet compression of preprocessing digital images

In this paper, we implemented a practical digital security system that combines digital correlation, wavelet compression with digital images preprocessing. The system has a biometric sensor; it is charge to capture the images and to digitize them. These images are preprocessed using wavelet based image compression and are skeleting for to stand out elements of the image that are considered of greater importance, eliminating the undesired signals, that because of the method of acquisition, or the conditions under which it was captured they appear in the same one. These images are stored in the data base, which to the being passed through different algorithms makes a compound filter, that serves as reference or pattern fingerprint for making the comparisons. These comparisons are showing in a graph where are observed amplitude different for each one from fingerprint, this make with help Fourier transformed and the correlation operations that allows quantifying the degree of similarity between two images. Depending on the results thrown by the system at the time of comparing a new fingerprint with the compound filter the access will be allowed or not the user.

Proposal of a bio-speckle descriptor for computing machine take decisions

The coefficient autocorrelation is a descriptor used in many applications with biospeckle technique. However the analysis of results is through of interpretation of graphs curves. In this paper us proposal a fast algorithm for the linearizing of autocorrelation coefficient; through of the average of slope between autocorrelation coefficients and thus the computing machine can take decisions for many application; for example: fruit classification, maturity detection, storage detection, seeds classification etc.

Portable equipment for determining ripeness in Hass avocado using a low cost color sensor

The avocado is a one climacteric fruit that not ripe on the tree because it produces a maturation inhibitor that passes the fruit through the pedicel, the ripening occurs naturally during storage or to be induced as required. In post-harvest ripening stage is basically determined by experience of the farmer or buyer. In this word us developed portable equipment for determining ripeness is hass avocado using a low cost sensor color sensor TC3200 and LCD for display result. The prototype read of RGB color frequencies of the sensor and estimates the stage of ripeness in fourth different stages in post-harvest ripening.

Image processing applied to measurement of particle size

Five different types of aggregates have been analyzed, and the size of particles on samples immersed in distilled water as silicon dioxide, titanium dioxide, styrenes and crushed silica particles is made; an attempt at applying the digital image processing (DIP) technique to analyze the particle size, we developed a system of measures microparticles using a microscope, a CCD camera and acquisition software and video processing developed in MATLAB. These studies are combined with laser light using measurements by diffractometry and obtain calibration in the system implemented, in this work we achievement measurement particle size on the order of 4 to 6 micrometers. The study demonstrates that DIP is a fast, convenient, versatile, and accurate technique for particle size analysis; the limitations of implemented setup too will be discussed.

Determining the quality of optical fiber splice by fusion by electric arc through spectral image processing

This paper develops and implements, can experimental method to characterize the process of splice optical fibers by fusion for determine the quality thereof. The procedure utilizes the Bragg diffraction law, allowing spectrally decomposed emitted light in the fusion splicing process. The experimental mounting used a diffraction grating to refract light, a video camera that allows capturing the image sequences during the complete process of fusion splicing, later and with the aid of the computational tool MATLAB is performed all the segmentation process, filtering, correlation and analysis of images obtained.

Correlation applied to the recognition of regular geometric figures

It developed a system capable of recognizing of regular geometric figures, the images are taken by the software automatically through a process of validating the presence of figure to the camera lens, the digitized image is compared with a database that contains previously images captured, to subsequently be recognized and finally identified using sonorous words referring to the name of the figure identified. The contribution of system set out is the fact that the acquisition of data is done in real time and using a spy smart glasses with usb interface offering an system equally optimal but much more economical. This tool may be useful as a possible application for visually impaired people can get information of surrounding environment.

Recognition and identification of faces using digital correlation

It developed a system capable of recognizing faces of people from their facial features, the images are taken by the software automatically through a process of validating the presence of face to the camera lens, the digitized image is compared with a database that contains previously images captured, to subsequently be recognized and finally identified. The contribution of system set out is the fact that the acquisition of data is done in real time and using a webcam commercial usb interface offering an system equally optimal but much more economical. This tool is very effective in systems where the security is of vital importance, support with a high degree of verification to entities that possess databases with faces of people.