International Journal of Innovative Research and Development

A. Madhuri , N. Suguna

Abstract

In order to guarantee communication efficiency and save network bandwidth, compression techniques can be implemented on digital content to reduce redundancy, and the quality of the decompressed versions should also be preserved. The two functions of data hiding and image compression can be integrated into one single module, which can avoid the risk of the attack from interceptors and increase the implementation efficiency. On the sender side, the blocks in the leftmost and topmost of the image are compressed by main codebook, each of the other residual blocks in raster-scanning order can be embedded with secret data and compressed simultaneously by SMVQ according to the current embedding bit. SMVQ is develop to alleviate the block artifact of the decompressed image and increase compression ratio, because the correlation of the neighboring block is consider and the indices of the sub codebooks are stored. After segmenting the image compressed codes into a series of sections by the indicator bits, the receiver can achieve the extraction of secret bits and image decompression successfully according to the index values in then segmented sections. On the receiver side image edge based harmonic inpainting is used for reconstructing lost or deteriorated parts of images. The proposed scheme shows the performances for hiding capacity, compression ratio and decompression quality.

Keywords

Data hiding, image compression, image inpainting, side match vector quantization.

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V. Madhurima , N. Suguna

Abstract

Universal Serial Bus (USB) is a new personal computer interconnection protocol, developed to make the connection of peripheral devices to a computer easier and more efficient. It reduces the cost for the end user, improves communication speed and supports simultaneous attachment of multiple devices (up to127) RS232, in another hand, was designed to single device connection, but is one of the most used communication protocols. An embedded converter from RS232 to USB is very interesting, since it would allow serial-based devices to experience USB advantages without major changes. This work describes the specification and development of such converter and it is also a useful guide for implementing other USB devices. The main blocks in the implementation are USB device, UART (RS232 protocol engine) and interface FIFO logic. The USB device block has to know how to detect and respond to events at a USB port and it has to provide a way for the device to store data to be sent and retrieve data that have been received UART consists of different blocks which handle the serial communication through RS232 protocol. There are a set of control registers to control the data transfer. The interface FIFO logic has FIFO to bridge the data rate differences between USB and RS232 protocols.

Keywords

First-in-first-out, Rs-232, Universal Asynchronous Receive Transmit, Universal Serial Bus

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