Text image secret sharing with hiding based on color feature

The Secret Sharing is a scheme for sharing data into n pieces using (k, n) threshold method. Secret Sharing becomes an efficient method to ensure secure data transmission. Some visual cryptography techniques don’t guarantee security transmission because the secret information can be retrieved if the hackers obtain the number of shares. This study present a secret sharing method with hiding based on YCbCr color space. The proposed method is based on hiding the secret text file or image into a number of the cover image. The proposed method passes through three main steps: the first is to convert the secret text file or image and all cover images from RGB to YCbCr, the second step is to convert each color band to binary vector, then divide this band in the secret image into four-part, each part is appended with a binary vector of each cover image in variable locations, the third step is converting the color space from YCbCr to RGB color space and the generated shares, hidden with covers, are ready for transmission over the network. Even if the hackers get a piece of data or even all, they cannot retrieve the whole picture because they do not know where to hide the information. The results of the proposed scheme guarantee sending and receiving data of any length. The proposed method provides more security and reliability when compared with others. It hides an image of size (234x192) pixels with four covers. The MSE result is 3.12 and PSNR is 43.74. The proposed method shows good results, where the correlation between secret and retrieved images is strong ranging from (0.96 to 0.99). In the proposed method the reconstructed image quality is good, where original and reconstructed images Entropy are 7.224, 7.374 respectively

Implementación en FPGA de un conversor de señal de video compuesto a señal VGA

This paper describes the design and implementation of a system for converting composite video signal to VGA signal, which performs the capture and display of video based on the ITU-R BT.601 standard for digital television monitors. The system has three main components: an analog sensor that delivers the composite digital video signal, a graphics card that converts analog video to digital in 4:2:2 sampling format and uses the color space YCbCr and finally a FPGA (NEXIS card 2 , with the integrated circuit 3s1200efg320 -5) where the design has been implemented for processing the video signal to be displayed on a monitor. In the FPGA have been developed 4:2:2 to 4:4:4 sampling conversion modules and the conversion module between YCbCr color space to RGB (color format used in display devices). The synthesis of the FPGA design has been made using the XST (Xilinx Synthesis Tool) that is part of the interface development ISE Project Navigator 13.3 of the Xilinx® company. The equations for the transformation between color spaces have been implemented and simulated in MATLAB ® for validation of results.En este artículo se presenta el diseño e implementación de un sistema de conversión de señal de video compuesto a señal VGA, el cual realiza la captura y despliegue de video basado en el estándar ITU-R BT.601 para monitores de televisión digital. El sistema cuenta con tres principales componentes: un sensor de video analógico que entrega la señal de video digital compuesta, una tarjeta digitalizadora que realiza la conversión del video analógico al digital en el formato de muestreo 4:2:2 y emplea el espacio de color YCbCr y finalmente un FPGA (tarjeta NEXIS 2, con el circuito integrado 3s1200efg320-5) en donde se ha implementado el diseño del procesamiento de la señal de video para poder ser desplegadas en un monitor. En el FPGA se han desarrollado los módulos de conversión de muestreo 4:2:2 al 4:4:4 y el módulo de conversión entre los espacios de color YCbCr al RGB (formato de color utilizado en los dispositivos de despliegue).  La síntesis del diseño en el FPGA se ha realizado utilizando la herramienta XST (Xilinx Synthesis Tool) que es parte de la interfaz de desarrollo ISE Project Navigator 13.3 de la compañía Xilinx®. Las ecuaciones para realizar la transformación entre los espacios de color han sido implementadas y simuladas en MATLAB® para la validación de resultados