In this paper we propose a new steganography technique which embeds the secret messages in frequency domain. According to different users' demands on the embedding capa c- ity and image quality, the proposed algorithm is divided into two modes and 5 cases. Unlike the space domain approaches, secret messages are embedded in the high frequency coefficients re- sulted from Discrete Wavelet Transform. Coefficients in the low frequency sub-band are pre- served unaltered to improve the image quality. Some basic mathematical operations are per- formed on the secret messages before embedding. These operations and a well-designed map- ping Table keep the messages away from stealing, destroying from unintended users on the inter- net and hence provide satisfactory security.

http://ir.lib.cyut.edu.tw:8080/bitstream/310901800/8254/1/6.pdf

A DWT Based Approach for Image Steganography

Methods and apparatus for embedding digital watermarks into a digital host content are provided. A digital host content is received, e.g., at a receiver or other device incorporating a receiver. One or more watermark embedding technologies is selected. Multiple embedding opportunities are identified within the host content. A subset of the identified embedding opportunities is selected. A multiplicity of digital watermarks are then embedded into the host content in accordance with the selected subset of embedding opportunities utilizing the one or more selected watermark embedding technologies. The selecting of the subset of embedding opportunities may be adapted to provide a desired tradeoff between levels of robustness, security, and transparency of the watermark. A plurality of watermarking embedding technologies may be selected and used in the embedding step.

Security enhancements of digital watermarks for multi-media content

Methods for adapting the operation of a system in response to the detection of embedded watermarks from a digital host content are provided. A digital host content is received and examined for the presence of watermarks. In response to the detection of embedded watermarks and in accordance with the value, type, density or spacing of the detected watermarks, one or more system reactions may take place. These reactions include conditionally allowing the system to resume its normal operation, prohibiting the system from resuming its normal operation, degrading the quality of the digital host content or changing the security status of the digital host content. In response to the extraction of weak watermarks that do not meet the desired system requirements, the extraction operation may be modified or extended to enable the detection of strong watermarks.

System reactions to the detection of embedded watermarks in a digital host content

Since several years, the protection of multimedia data is becoming very important The protection of this multimedia data can be done with encryption or data hiding algorithms To decrease the transmission time, the data compression is necessary Since few years, a new problem is trying to combine in a single step, compression, encryption and data hiding So far, few solutions have been proposed to combine image encryption and compression for example Nowadays, a new challenge consists to embed data in encrypted images Since the entropy of encrypted image is maximal, the embedding step, considered like noise, is not possible by using standard data hiding algorithms A new idea is to apply reversible data hiding algorithms on encrypted images by wishing to remove the embedded data before the image decryption Recent reversible data hiding methods have been proposed with high capacity, but these methods are not applicable on encrypted images In this paper we propose an analysis of the local standard deviation of the marked encrypted images in order to remove the embedded data during the decryption step We have applied our method on various images, and we show and analyze the obtained results

/pdf/a-reversible-data-hiding-method-for-encrypted-images-y3s3siurez.pdf

A Reversible Data Hiding Method for Encrypted Images

Systems and methods are provided for monitoring transmissions of media content (such as audio and audiovisual content) in order to obtain independent and objective data regarding the use of specific media content recordings or works within the transmissions. Processing and reporting of such data is provided in various ways to serve a variety of business needs. Methods for employing content identification technology to efficiently and automatically obtain reliable, accurate, and precise monitoring data are also disclosed. Various information products and services based on such monitoring systems are proposed.

Media monitoring, management and information system

Combinational image watermarking in the spatial and frequency domains

An integrated circuit (IC) has logic and timing circuits that are coupled to discrete circuitry to provide protection and indications whenever an AC adapter that is faulty or has improper voltage levels or polarity are plugged into a system. In particular, the IC device provides over-voltage, under-voltage, and reversed-polarity protections to an electronic system to keep the electronic system from being damaged by an alternating current (AC) adapter having an improper voltage range or voltage polarity. It also provides a protection that prevents an adapter from powering a host system that has a short-circuit fault.

Scott Y.T. Wu

Papers

Combinational image watermarking in the spatial and frequency domains

Power adapter interface circuitry for protecting a battery operated system