Showing papers in "IEEE Transactions on Consumer Electronics in 2000"

The JPEG2000 still image coding system: an overview

Abstract: With the increasing use of multimedia technologies, image compression requires higher performance as well as new features. To address this need in the specific area of still image encoding, a new standard is currently being developed, the JPEG2000. It is not only intended to provide rate-distortion and subjective image quality performance superior to existing standards, but also to provide features and functionalities that current standards can either not address efficiently or in many cases cannot address at all. Lossless and lossy compression, embedded lossy to lossless coding, progressive transmission by pixel accuracy and by resolution, robustness to the presence of bit-errors and region-of-interest coding, are some representative features. It is interesting to note that JPEG2000 is being designed to address the requirements of a diversity of applications, e.g. Internet, color facsimile, printing, scanning, digital photography, remote sensing, mobile applications, medical imagery, digital library and E-commerce.

A new remote user authentication scheme using smart cards

Abstract: We propose a new remote user authentication scheme using smart cards. The scheme is based on the ElGamal's (1985) public key cryptosystem. Our scheme does not require a system to maintain a password table for verifying the legitimacy of the login users. In addition, our scheme can withstand message replaying attack.

An efficient remote use authentication scheme using smart cards

Abstract: Based on the discrete logarithm problem, Hwang and Li (see ibid., vol.46, no.1, p.28-30, Feb. 2000) proposed a remote user authentication scheme using smart cards. Their scheme is very novel because no password table is required to keep in a system. In this paper, we further propose an efficient and practical remote user authentication scheme using smart cards. The proposed scheme not only provides the same advantages as that of Hwang and Li's scheme, but also significantly reduces the communication and computation costs.

New frame rate up-conversion using bi-directional motion estimation

Abstract: We propose a new frame rate up-conversion algorithm for high quality video. In the proposed scheme, bi-directional motion estimation (ME) is performed to construct the motion vector (MV) field for the frame to be interpolated. Unlike conventional motion-compensated interpolation (MCI) algorithms, the proposed technique does not produce any overlapped pixel and hole region in the interpolated frame, and thus can utilize the overlapped block motion compensation technique to reduce the blocking artifacts. The proposed algorithm is very simple to implement on consumer products when compared to conventional MCI methods. Computer simulation shows a high visual performance of the proposed frame rate up-conversion algorithm.

Cryptanalysis of a remote user authentication scheme using smart cards

Abstract: We present a cryptanalysis of a remote user authentication scheme proposed by Hwang and Li (see ibid., vol.46, no.1, p.28-31, 2000). We show that Hwang-Li's scheme is breakable. A legitimate user can impersonate other legal users and pass the system authentication.

Joint wavelet and spatial transformation for digital watermarking

Abstract: A new watermarking scheme which incorporates wavelet and spatial transformation has been developed for digital images. This algorithm utilizes the wavelet multiresolutional structure to construct the image frequency components and the chaotic transformation as two dimensional integer vector generators for spatial transform to select the location during the watermark embedding. To efficiently embed the watermark within the image without the loss of image quality and provide the robustness for the watermark detection under attacks, a modular based spatial threshold and adjustment scheme of the wavelet coefficients has been developed in this research. Unlike other watermarking schemes which usually rely on significantly large amount of side information for watermark detection, our algorithm need only few key parameters to detect the watermark with meaningful content. Compared with some known approaches of watermarking schemes, this algorithm results in superior robustness and information protection for keeping watermark intact under image processing attacks like image compression.

Digital watermarking of still images with gray-level digital watermarks

Abstract: Digital watermarking has been presented in the literature as a technique to protect the copyright of multimedia data. But most of these literature concentrates on algorithms of embedding one-dimensional watermarks or two-dimensional binary digital watermarks. In this paper, a method of embedding a gray-level digital watermark into an image is proposed. By the stack filter threshold decomposition technique, a gray-level digital watermark is decompounded into a series of binary digital images for implementing multiple watermarking. The experimental results show that the proposed techniques are tolerant to reasonable image processing operations and the lossy compression techniques such as Joint Photographic Experts Group (JPEG).

Performance of channel estimation methods for OFDM systems in a multipath fading channels

Abstract: In this paper, a Gaussian interpolation filter and cubic interpolation filter are presented as more accurate interpolation filters compared to the conventional linear interpolation filter. In addition to an interpolation filter, a low pass filter using FFT and IFFT is also presented to reduce the noisy components of a channel estimate obtained by an interpolation filter. Channel estimates after low-pass filtering combined with interpolation filters can lower the error floor compared to the use of only interpolation filters. Computer simulation demonstrates that the presented channel estimation methods exhibit improved performance compared to the conventional linear interpolation filter. OFDM and in particular coded OFDM DAB systems are discussed.

Fault resilient and compression tolerant digital signature for image authentication

Abstract: Many watermarking schemes have been proposed to protect the authority of the image producer. These schemes can help the image producer to assert the ownership when their images are illegal reproduced. A buyer may want to make sure that the received commodity is from the legal sender and prove its integrity. In this situation, digital signature schemes can meet these requirements. In this sender-receiver protocol, images are always compressed before transmission. So compression tolerant image-features have to be designed to replace the hash functions in conventional digital signature schemes. In this paper, a public-key based fault resilient and compression tolerant digital signature is proposed. The proposed method can not only verify the authenticity and the integrity of commodities, but also can locate the illegal modifications. Furthermore, the proposed method can provide the capability of recovery if images are tampered.

Adaptive beamforming algorithm for OFDM systems with antenna arrays

Abstract: This paper presents an adaptive beamforming algorithm for an OFDM system with an adaptive array antenna. The proposed algorithm for adaptive beamforming in the OFDM system is derived by (1) calculating the pilot error signals in the frequency domain, (2) transforming the frequency-domain error signals into time-domain error signals, (3) updating the filter coefficients of the adaptive beamformer in the direction of minimizing the MSE. The convergence behavior and performance improvement of the proposed approach are investigated through computer simulation by applying it to the conventional OFDM system.

OFDM carrier and sampling frequency synchronization and its performance on stationary and mobile channels

Abstract: All-digital automatic frequency control (AFC) for consumer applications must be both reasonably simple and effective in all kinds of environments. This paper presents the AFC synchronization strategy and algorithms implemented in a DVB-T compliant single-chip CMOS device for COFDM terrestrial digital TV reception previously developed by Fechtel, Schollhorn, Speth, Fock and Schotten (see ibid. vol.44, no.3, p.1012-18, 1998) and gives results on AFC performance in both stationary and mobile environments.

Interpolation using neural networks for digital still cameras

Abstract: In this paper we present a color interpolation technique based on artificial neural networks for a single-chip CCD (charge-coupled device) camera with a Bayer color filter array (CFA) Single-chip digital cameras use a color filter array and an interpolation method in order to produce high quality color images from sparsely sampled images We have applied 3-layer feedforward neural networks in order to interpolate a missing pixel from surrounding pixels And we compare the proposed method with conventional interpolation methods such as the bilinear interpolation method and cubic spline interpolation method Experiments show that the proposed interpolation algorithm based on neural networks provides a better performance than the conventional interpolation algorithms

Partial-encryption technique for intellectual property protection of FPGA-based products

Abstract: The configuration-data sequence of a field-programmable gate array (FPGA) is an intellectual property (IP) of the original designer. This paper proposes a partial-encryption (PE) technique for IP protection of configuration-data sequences by means of increasing the reverse-engineering cost. The PE technique encrypts a few selected data of the sequence. These data are selected in a judicious way such that, when a rival competitor copies the partially encrypted sequence into a cloned product, the cloned product performs the expected task to a certain degree of correctness but not absolutely error-free. Debugging is required. It is shown that, without an initial knowledge that a reverse-engineering countermeasure is employed, the PE technique outperforms the full-encryption technique in terms of the reverse-engineering cost. This paper describes implementation details of the proposed PE technique. Issues regarding system designs that embed hidden imperfections are also discussed.

Digital watermarking using zerotree of DCT

Abstract: A watermarking technique has been proposed as a method to embed an invisible signal into multimedia data so as to attest the owner identification and discourage the unauthorized copying In this paper, an efficiently DCT based watermarking technique is proposed In the proposed method, we take advantage of the zerotree in the rearranged DCT coefficients to embed watermark into image and extract the watermark from the watermarked image more efficiently The proposed method can directly extract the embedded watermark from the watermarked image without using the original image, so it is feasible to implement it in a real time system A scheme for spreading the watermarking information is also used to provide the robustness of the digital watermark The experimental results show that the imperceptibility and robustness of the digital watermark can be guaranteed

Adaptive scan rate up-conversion system based on human visual characteristics

Abstract: Current NTSC systems employ an interlaced scan scheme where visually annoying artifacts, such as line flickers, large area flickers, and edge flickers, are inevitably generated and more objectionable with a larger display. With the development of HDTV systems, how an NTSC signal can be displayed in an HDTV system has also become a problem. Accordingly in order to solve these problems, many adaptive scan rate up-conversion systems have been proposed. The proposed system consists of a modified edge directional line averaging (ELA) interpolation module and contrast enhancement module. The modified ELA interpolation module reduces the visually annoying artifacts induced by an interlaced scan scheme whereas the degradation in the contrast and details due to interpolation processing is compensated by the contrast enhancement module. Moreover, the proposed system is easy to implement and the VLSI architecture is very simple. This new system was mainly developed for doubling the scan rate in an NTSC system; however, it can also be used in the format conversion in an HDTV system.

An effective de-interlacing technique using motion compensated interpolation

Abstract: We propose a new de-interlacing algorithm using motion compensated interpolation. In the proposed scheme, motion estimation is first performed between the same parity fields, i.e., the previous and the next field, and then the motion vector is refined in the interpolated field. In conventional motion compensated schemes, a pre-filter such as line averaging is applied to interpolate missing lines before the motion estimation between the opposite parity fields. The proposed scheme does not require the pre-filter because block matching is performed between the same parity fields. For further improvement, a five-point median filter with temporal emphasis is used to reduce the interpolation error caused by incorrect motion. Computer simulation results indicate that the proposed scheme provides a better visual performance than conventional de-interlacing algorithms.

A watermarking sequence using parities of error control coding for image authentication and correction

Abstract: A novel function for image watermarking is proposed We show how the watermarking sequence can be used for correction of illegal modifications To make this task possible, the parities generated by the conventional error control coding (ECC) technique is used for the watermarking sequence Then, the receiver can correct any alterations by applying the ECC decoding To increase the correction capability we also adopt a scrambling scheme before the encoding to change a burst type of content modifications (ie, errors) into a random noise The scrambling key can be also used as a key for the authentication of the sender

Mobile multimedia-challenges and opportunities

Abstract: Today, we observe the creation of an increasing number of multimedia consumer devices for mobile and home use. This includes set-top-boxes, game consoles, personal digital assistants (PDA), e-books, but also mobile phones. Although these devices have many things in common with desktop PCs-above all Internet access-it is widely accepted that they will serve a different purpose. Many committees and companies are currently trying to define the open application platform for tomorrow's consumer terminals for home use, among others the so-called Multimedia Home Platform (MHP) of the European Digital Video Broadcasting (DVE) project. Meanwhile, on the cellular end of the multimedia business, portable appliances like cellular phones, e-books and PDAs are evolving to multimedia terminals, starting from narrow band Internet services like the Wireless Application Protocol (WAP) and slowly adopting video technologies. One of the main obstacles to overcome is bandwidth limitation-even for 3G mobile systems-and broadcast technology is considered to be a serious candidate to fill this gap, both for TV and data services. A special challenge is to provide multimedia services in vehicles, where, due to the static environment relative to the driver, some requirements for mobile and static terminals apply at the same time. This paper summarizes some trends and opportunities of mobile multimedia-especially in the DVB and GSM (Global System for Mobile communications) domain, while outlining the different requirements for mobile, home and car use of multimedia services.

Rate control algorithm for fast bit-rate conversion transcoding

Abstract: In this paper, a new rate control algorithm is introduced as a solution for fast rate control requirements in transcoding. The specific transcoding problem mentioned in this paper is referred to as bit-rate conversion. For video services in heterogeneous network environments, it is necessary to convert the bit-rate of a compressed video to match it to transmission channels of lower capacity. The transcoding of coded video streams by requantization in the DCT (discrete cosine transform) domain is considered as a promising technique for its low complexity and acceptable picture quality. We carried out extensive simulations for many kinds of video sequences to find a novel R-Q (rate-quantization) model in the requantization process and found a piecewise linearly decreasing model. Exploiting this model we propose an efficient rate control algorithm for fast transcoding. Since the proposed algorithm requires much lower complexity than conventional algorithms and inherently avoids additional steps of implementation for a scene adaptive rate control in the transcoder, it has a significant advantage as a rate control algorithm for transcoding.

New fast-search algorithm for block matching motion estimation using temporal and spatial correlation of motion vector

Abstract: This paper introduces a new technique that reduces the search time and improves the motion estimation accuracy by using the high temporal and spatial correlation of a motion vector. Instead of using a fixed first-search point, as in previous search algorithms, the proposed method identifies a more accurate first search point through compensating the search area based on the temporal and spatial correlation of a motion vector. Accordingly, the proposed algorithm is based on the consistent directivity and center-biased distribution property of a motion vector. As a result, the performance of the motion estimation is improved and the total number of search points used to find the motion vector of the current block is significantly reduced. Simulation results showed that the PSNR values improved up to 3.6 dB, depending on the image sequence, and advanced on average by about 1.7 dB. The comparative results demonstrated that the performance of the proposed algorithm was better than those of other fast-search algorithms whether the image sequence contained fast or slow motion, and similar to the performance of a full-search (FS) algorithm. Furthermore, the performance of the proposed scheme produced a superior subjective picture quality compared with other fast-search algorithms.

Video browsing system based on compressed domain feature extraction

Abstract: We present a video browsing system that dynamically extracts features and other content-description (meta-data) from compressed video. We devise a description scheme for a video browsing system that combines color and motion descriptors extracted in the compressed domain. The extraction is fast and enables our proposed dynamic feature extraction based video browsing system. We examine the tradeoff between fast feature extraction and accuracy of matching to arrive at a combination of color and motion descriptors that is easy to extract and provides accurate matching.

Image refining technique using digital watermarking

Abstract: An image refining technique is proposed. The digital watermarking and Reed-Solomon (RS) coding techniques are adopted to provide the image refining. The RS codewords' parities of original image are used as a watermark to be embedded in the original image. The watermark can provide the error correction and detection capability for the original image (refining function). Meanwhile, we take the advantage of the parity bits of the rearranged DCT coefficients in the lower frequency subbands of the quantized DCT block to provide the robustness and imperceptibility requirement for watermarking technique. The proposed method can directly extract the embedded watermark from the watermarked image without using the original image, so it is feasible to implement it in a real time system. The experimental results show that the error correction and detection capability, imperceptibility, and robustness of the watermarking technique can be guaranteed.

Multiresolution watermarking for video based on gray-level digital watermark

Abstract: A method of embedding a digital watermark image in video is proposed in this paper. By two-dimensional and three-dimensional multiresolution signal decomposing, the decomposed watermark images with different resolution are embedded in the corresponding resolution of the decomposed video. To enhance the robustness of watermarking, the watermark information is coded by error correction coding of Hamming code in our algorithm. Experimental results show that the proposed technique is robust enough against the attacks of frame dropping, averaging and lossy compression.

A shift-resisting public watermark system for protecting image processing software

Abstract: Digital watermarking is a technique used to protect the ownership of images and their associated software. A useful watermark scheme should be visually imperceptible and must be robust to resist various attacks: such as JPEG compression, pixel-shifting, cropping, blurring, etc. In this paper, we propose a public watermarking system to protect image processing software and images. We embed a binary image as a watermark in the DCT domain and the watermarked image is imperceptible by the human visual system and robust to image shifting or cropping. We use a feature-based approach to synchronize the watermark positions during embedding and extracting. For better image quality, the more complex in a block, the more bits can be embedded. Our approach doesn't need the original image for watermark extraction, which is a useful feature in protecting software applications such as real-time generated panorama images.

Near-lossless complexity-scalable embedded compression algorithm for cost reduction in DTV receivers

Abstract: This paper presents a novel complexity-scalable technique to reduce the memory costs of an MPEG-2 decoder by a factor of four to six, by recompressing the I- and P-reference pictures prior to motion-compensated reconstruction. The proposed scheme features some unique characteristics, like robustness for multiple encodings and high memory and memory-bandwidth reduction factors. At the same time, the near-lossless quality obtained is preserved, independently of the ratio between the input and display resolution and transmission/storage bit-rates, because no interference between the memory reduction algorithm and the MPEG-2 decoder occurs. Due to the inherent scalability of the presented algorithm, trade-offs between memory, silicon costs or over-all system costs, and image quality can be easily made. The proposed embedded compression algorithm can also be used for memory and memory-bandwidth reduction in alternative systems, like video coding ICs (e.g. MPEG-4) and memory intensive image processing ICs (e.g. de-interlacing and 100-Hz conversion).

Highly robust biometric smart card design

Abstract: An architecture of a highly reliable smart card is proposed. Dual on-chip biometric fingerprint sensors, implemented with different technologies, are integrated with the smart card architecture for increase security and reliability.

Privacy and non-repudiation on pay-TV systems

Abstract: Privacy is becoming more and more precious in modern society. A viewer's TV-watching habits may reveal information about him/her that will make the viewer uncomfortable or cause him/her inconvenience. People should have the right to assert their privacy about the TV-programs they are in the habit of watching. This article develops a practical conditional access system (CAS) mechanism for pay-TV systems to secure such personal privacy in watching TV-programs. Disputes about transactions are usually unavoidable and can endanger the life of any business, including commercial TV systems. In order to prevent possible disputes or settle existing disputes, pay-TV systems need non-repudiation services to provide some evidence-digital signatures, for example-such that a fairer environment can be created. The conventional approaches for pay-TV systems have not provided any non-repudiation services to facilitate dispute resolution. This article also intends to demonstrate the use of digital signature techniques to make pay-TV systems fairer than before.

The implication of the next-generation wireless network design: cellular mobile IPv6

Abstract: The initiatives to add mobility to the Internet and packet data services for next-generation cellular systems are being considered by many mobile service providers. IPv6 is a new version of the Internet protocol that was standardized by the Internet Engineering Task Force (IETF). It supports mobility and is presently being standardized by the IETF Mobile IP Working Group. At the same time, cellular is an inevitable and developing architecture for the Personal Communication Service system (PCS). In this paper, cellular mobile IPv6 (CMI), a new algorithm that is migrated from mobile IPv6 is proposed for mobile nodes moving among small wireless cells at high speed. It is important for future mobile communication environments and should eventually, integrate its functions with the Internet. The purpose of this paper is to solve the problems of a communication break within smaller cellular coverage during high-speed movement with packet-switched data or the real-time voice messages. Thus, voice over IP (VoIP) packets were chosen to implement the system. Simulation results show smooth and non-breaking handoff during high-speed movement using the proposed algorithm.

Parametric cubic convolution scaler for enlargement and reduction of image

Abstract: An adaptive version of cubic convolution interpolation is derived for the enlargement or reduction of digital images by arbitrary scaling factors. In this paper, the problem of image interpolation is dealt with space-variant ones by introducing the adaptation of the interpolation kernel. The adaptation is performed in each subpixel which is predicted from the neighbor pixels. The interpolation kernel is modified to adapt local properties of the original data. During the adaptation phase, we modify the parameter value on which the interpolation is based to account for the concavity and continuity of data. Simulation results show that the proposed algorithm enable a reliable scaling technique with arbitrary scale factor. The algorithm exhibits significant improvement in the minimization of information loss when compared with the conventional interpolation algorithms.