Showing papers by "Russell M. Mersereau published in 2001"

A novel approach for increasing security and data embedding capacity in images for data hiding applications

Abstract: Data hiding in multimedia is the process of secretly embedding information into data sources such as image, video, or audio signals without changing the perceptual quality of the data source. We present a novel blind data hiding technique for hiding information in still images. This technique is based on embedding the information in the transform domain, after decorrelating the samples in the spatial domain. This results in a significant increase in the number of transform coefficients that can be used to transmit the hidden information. The technique is suitable for a variety of data hiding applications such as steganography, data authentication and captioning. The technique achieves a higher and more secure data embedding rate than existing data embedding transform domain techniques developed for these particular applications.

Secure blind image steganographic technique using discrete Fourier transformation

Abstract: We present a new steganographic technique for covert communications. The technique embeds the hidden information in the DFT domain after permuting the image pixels in the spatial domain using a key. The permutation process introduces randomness into the cover image and results in a significant increase in the number of transform coefficients that can be used to transmit the hidden information. The hidden information is embedded using a quantization technique. The perceptual and statistical properties of the cover and the stego images remain similar for small quantization steps. The security of the system is examined against known stego attack.

Multiple description coding with multiple transmit and receive antennas for wireless channels: the case of digital modulation

Abstract: An effective way of providing error resilience with a relatively small reduction in compression ratio is multiple description coding (MDC). All multiple description codes to date assume the existence of multiple independent "on-off" channels between the transmitter and receiver. Each link is either broken in which case the symbols or packets are completely lost, or it functions properly, in which case symbols are received free of errors. This channel model is appropriate for wireline networks, such as the Internet, but it may not be applicable to other commonly used channels such as wireless channels. We replace the parallel independent on-off channel model with wireless channel models such as a Rayleigh fading model. We also communicate using multiple transmit and receive antennas over the channel. Furthermore, we use digital bandpass modulation to transmit the source symbols.

A temporal error concealment method for MPEG coded video using a multi-frame boundary matching algorithm

Abstract: Compressed video sequences are very sensitive to channel disturbances when they are transmitted through an unreliable environment such as a wireless channel. The transmission errors not only corrupt the current decoded frame, but also propagate to the succeeding frames. Many error concealment methods have been proposed to recover the errors by exploiting temporal and spatial correlation. In this paper, we develop a multi-frame boundary matching algorithm (MF-BMA), which utilizes the boundary smoothness property not only in the decoded frame but also in the succeeding frames. The experimental results demonstrate that the proposed algorithm can provide better performance, especially when horizontal edges exist across the lost macroblocks.

Secure fragile digital watermarking technique for image authentication

Abstract: We present a new fragile digital watermarking technique that can be used as a digital signature for data authentication. The technique presented is blind, efficient, secure and can detect and locate minor tampering applied to the image pixels. The technique is suitable for certain classes of image formats such as gif, tif or bitmap images. The digital signature is inserted by decorrelating the image samples in the spatial domain, then embedding the watermark in the transform domain of the decorrelated image. The mark is embedded using quantization and modulo arithmetic techniques with a small quantization step size. Any tampering with the image will create errors in the embedded bits, which can be easily detected.

Bayesian resolution-enhancement framework for transform-coded video

Abstract: Resolution enhancement for video sequences has always been an attractive application in multimedia signal processing. "Superresolution" methods, that combine non-redundant information from a set of low-resolution images, are beginning to be applied to the most popular video compression standard, MPEG. Bayesian approaches, which are very successful for raw video, largely fail for MPEG video, since they do not incorporate the compression process into their models. This compression process introduces quantization noise, which is comparable to the additive noise that is used in the Bayesian models. We present an analytical derivation that combines the quantization and additive noises in a stochastic framework for MPEG-compressed video. This is a general framework in the sense that different video acquisition models, source statistics, implementation techniques can be used with it.

Decoding of half-rate wavelet codes; Golay code and more

Abstract: The primary goal of this paper is to give examples of the recently developed (finite-field) wavelet coding method by studying the encoder and decoder for some half-rate codes. We propose a decoding methodology based on estimating the polyphase components of the channel error pattern. To demonstrate the striking computational savings of the wavelet coding method over alternatives, we show that bounded-distance decoding of the (24,12,8) Golay code requires only weight computations (or at the worst case, it needs a cyclic lookup table of table size 12). The simplicity and computational savings that finite field wavelets offer for the encoding and decoding of wavelet block codes indicate their powerful capacities for error control coding applications.

Gray-scale resolution enhancement

Abstract: The number of bits assigned to represent the color intensity at image pixels is usually referred as the bit depth. When the bit depth is not sufficient, images suffer from ridge-like structures known as false contours. Bit-depth limitations become important when low-contrast details are required, as in medical imaging, aerial/satellite photography, and high-quality scanning: applications. In this paper, we investigate a method for increasing bit depth. Specifically, we show that when a sequence of video frames is available, then it is possible to achieve a higher bit depth through a projections onto convex sets (POCS) based reconstruction method.

Landmine signatures in ground-penetrating radar

Abstract: The Mine Hunter/Killer system employs a ground penetrating radar (GPR). Twenty antennas sample a 3m swath to measure a 3D depth return from the earth as the vehicle moves forward in a lane. Data has been collected on shallow and deep, metal and low metal landmines. Samples signatures from a metal and plastic cased landmines buried at 6 inches are presented. In each example a hyperbolic signature is observed. Two feature sets that exploit the hyperbolic shape for false alarm reduction are presented. The first uses a pixel clustering technique to isolate the hyperbola in 3D. A vector of size/shape features is extracted and combined with a quadratic polynomial discriminant into a single value. The second feature set utilizes the radon transform. The radon transform sums the tails of the hyperbola allowing the algorithm to differentiate between surface clutter, which tends to be oriented horizontally in depth, and the diagonals of the hyperbola. Performance curves for both the 3D size/shape features and the radon feature are presented.

Wavelet convolutional codes with bipartite trellises

Abstract: We introduce a method novel to generate new types of time-varying convolutional codes using finite-field wavelets. These codes have a new type of trellis that we refer to as a bipartite (or k-partite) trellis. An important feature of the k-partite trellises is their reduced decoding complexity.

Robust adaptive digital watermark for still images using hybrid modulation

Abstract: A digital watermark is a short sequence of information containing an owner identity or copyright information embedded in a way that is difficult to erase. We present a new oblivious digital watermarking technique for copyright protection of still images. The technique embeds the watermark in a subset of low to mid frequency coefficients. A key is used to randomly select a group of coefficients from that subset for watermark embedding. The original phases of the selected coefficients are removed and the new phases are set in accordance with the embedded watermark. Since the coefficients are selected at random, the powers of the low magnitude coefficients are increased to enhance their immunity against image attacks. To cope with small geometric attacks, a replica of the watermark is embedded by dividing the image into sub-blocks and taking the DCT of these blocks. The watermark is embedded in the DC component of some of these blocks selected in an adaptive way using quantization techniques. A major advantage of this technique is its complete suppression of the noise due to the host image. The robustness of the technique to a number of standard image processing attacks is demonstrated using the criteria of the latest Stirmark benchmark test.

Secure image transform domain technique for steganographic applications

Abstract: Digital steganography is the art of secretly hiding information inside a multimedia signal in such a way that its very existence is concealed. In this paper, we present a new steganographic technique for covert communications. The technique embeds the hidden information in the transform domain after decorrelating the image samples in the spatial domain using a key. This results in a significant increase in the number of transform coefficients that can be used to transmit the hidden information, and therefore, increases the data embedding capacity. The hidden information is embedded in the transform domain after taking a block DCT of the decorrelated image. A quantization technique is used to embed the hidden data. The decoding process requires the availability of the same key that was used to decorrelate the image samples. By using quantization techniques, the hidden information can be recovered reliably. If the key is not available at the decoder it is impossible to recover the hidden information. Hence, this system is secure against removal attacks. The statistical properties of the cover and the stego image remain identical for small quantization steps. Therefore, the hidden data cannot be detected. The data embedding system is modeled as transmitting information through a Gaussian channel.

Theory and applications of data hiding in still images

Abstract: There are several applications in image communication where digital data is incorporated into the image. These applications include digital watermarking for intellectual property protection and authentication, captioning, and steganography in which two or more parties can communicate through an invisible or “subliminal” covert communication channel. These applications range in the amount of data embedded, security, hostility of the attack and protection against deliberate or incidental attacks. This research examines the issue of information hiding in still images and its application to digital multimedia applications. It develops a general model for still images as a constrained type covert communication channel. Novel schemes for data embedding are developed for different data hiding applications such digital watermarking and steganography. Tradeoffs between data emedding capacity, security, and robustness to attacks are examined. Information theoretic approaches are developed to give bounds for estimating the capacity to hide information for these schemes. Analysis and design for these schemes for data hiding application is discussed.

A multi-frame blocking artifact reduction method for transform-coded video

Abstract: A major drawback of block-based still image or video compression methods at low rates are the visible block boundaries that are also known as blocking artifacts. Several methods have been proposed in the literature to reduce these artifacts for video sequences. However, most are simply adaptations of still image blocking artifact reduction methods, which do not exploit temporal information. We propose a novel multi-frame blocking artifact reduction method that incorporates temporal information effectively. This method uses the spatial correlations that exist between the successive frames to define constraint sets at multiple frames and provides a Projections Onto Convex Sets (POCS) solution. The proposed method operates solely on transform domain (DCT) data, and hence provides a solution that is compatible with the observed video. It does not need to make any spatial smoothness assumptions, which are typical with blocking artifact reduction algorithms for still images.

Object Modeling, Coding, and Transmission for Multimedia Communications

Abstract: This paper discuses object modeling, coding, and transmission for multimedia communications in the desktop environment. To reduce video quality degradation caused by coding distortion and networking. errors, we consider the compression and transmission of multimedia signals in a joint fachion. First, a three-level signal representation model is developed to connect 3-D graphics with video pixel information through 2-D object shapes, Second, nonrigid facial motion is modeled and is used to synthesize video images. Third, the video coding rates are adapted based on feedback of the network states and receivers.