6 research outputs found

    UNA COMPARACIÓN DE REDUCCIÓN DE RUIDO EN IMÁGENES DIGITALES UTILIZANDO UN MODELADO ESTADÍSTICO DE COEFICIENTES WAVELET Y FILTRADO DE WIENER

    Get PDF
    Este trabajo presenta un método de disminución de ruido en imágenes digitales, basado en un enfoque Bayesiano de dos etapas con ajuste empírico. Se estiman los coeficientes de una transformada wavelet de la imagen donde se ha reducido el ruido, utilizando una estimación lineal con un criterio de minimización del error cuadrático medio. Estos coeficientes constituyen una estimación deseable de la varianza de los coeficientes wavelet de la imagen libre de ruido

    System for creating and authentication credentials

    No full text
    This article present a system for creating and credential authentication personal identi- fication (ID) safe, using one-dimensional and two-dimensional barcodes, data encryption and symmetric key technique watermark. To do this, a watermark is inserted on the photo of the user, generated from a unique identification code which will be available in printed credential so that at the time of validation of the credential is carried by calculating the cross-correlation between the watermark contained in the photograph of the user and the watermark calculated at the time of validation using the same unique identification code. We show that proper selection of parameters for inserting the watermark: length, gain, position of the watermark and decision threshold, are essential to ensure the proper functioning of the proposed scheme, ensuring maintain sufficient quality in visual image to the user recognition and in turn be robust enough to withstand the attack of converting digital-analog (D / A) and analog-digital (A/D).System for creating and authentication credential
    corecore