Until today, digital image watermarking has not been large-scale used in the industry. The first reason is that the watermarking efficiency is low and the real-time performance cannot be satisfied. The second reason is that the watermarking scheme cannot cope with various attacks. To solve above problems, this paper presents a multi-domain based digital image watermarking scheme, where a fast DFT (Discrete Fourier Transform) based watermarking method is proposed for synchronization correction and an IWT-DCT (Integer Wavelet Transform-Discrete Cosine Transform) based watermarking method is proposed for information embedding. The proposed scheme has high efficiency during embedding and extraction. Compared with five existing schemes, the robustness of our scheme is very strong and our scheme can cope with many common attacks and compound attacks, and thus can be used in wide application scenarios.

The main purpose of Codemark is to distribute digital contents using offline media. Due to the main purpose of Codemark, Codemark cannot be used on digital images. It has high robustness on only printed images. This paper presents a new color code called Robust Index Code (RIC for short), which has high robustness on JPEG Compression and Resize targeting digital images. RIC embeds a remote database index to digital images so that users can reach to any digital contents. Experimental results, using our implemented RIC encoder and decoder, have shown high robustness on JPEG Comp. and Resize of the proposed codemark. The embedded database indexes can be extracted 100% on compressed images to 30%. In conclusion, it is able to store all the type of digital products by embedding indexes into digital images to access database, which means it makes a Superdistribution system with digital images realized. Therefore RIC has the potential for new Internet image services, since all the images encoded by RIC are possible to access original products anywhere.

Protanopes and deuteranopes are difficult to distinguish some color pairs. In this letter, a new lightness modification method which considers the Craik-O'Brien effect is proposed. The lightness modification is performed at parts which are difficult to distinguish in the protanopia or deuteranopia. Experiments show the validity of the proposed method.

This paper proposes two algorithms to balance energy consumption among sensor nodes by distributing the workload of image compression tasks within a cluster on wireless sensor networks. The main point of the proposed algorithms is to adopt the energy threshold, which is used when we implement the exchange and/or assignment of tasks among sensor nodes. The threshold is well adaptive to the residual energy of sensor nodes, input image, compressed output, and network parameters. We apply the lapped transform technique, an extended version of the discrete cosine transform, and run length encoding before Lempel-Ziv-Welch coding to the proposed algorithms to improve both quality and compression rate in image compression scheme. We extensively conduct computational experiments to verify the our methods and find that the proposed algorithms achieve not only balancing the total energy consumption among sensor nodes and, thus, increasing the overall network lifetime, but also reducing block noise in image compression.

In this letter, we first study the impact of the basic reference frame jitter on the digital image stabilization. Next, a method for stabilizing the digital image sequence based on the correction for basic reference frame jitter is proposed. The experimental results show that our proposed method can effectively decrease the excessive undefined areas in the stable image sequence resulting from the basic reference frame jitter.

The letter proposes a novel subsampling-based digital image watermarking scheme resisting the permutation attack. The subsampling-based watermarking schemes have drawn great attention for their convenience and effectiveness in recent years, but the traditional subsampling-based watermarking schemes are very vulnerable to the permutation attack. In this letter, the watermark information is embedded in the average values of the 1-level DWT coefficients to resist the permutation attack. The concrete embedding process is achieved by the quantization-based method. Experimental results show that the proposed scheme can resist not only the permutation attack but also some common image processing attacks.

Data accessed by many sites are replicated in distributed environments for performance and availability. In this paper, replication schemes are examined in parallel image convolution processing. This paper presents a system architecture that we have developed with CORBA (Common Object Request Broker Architecture) for the processing. Employing CORBA enables us to make use of a cluster of workstations, each of which has a different level of computing power. The paper also describes a parallel and distributed image convolution processing model using replicas stored in a network of workstations, and reports some experimental results showing that our analytical model can agree with practical situations.

The recent sight system requires high stabilization functions for the longer range of observation and the higher kill probability. To this end, it is necessary to compensate rotational disturbances which are not stabilized with the conventional 2-axes stabilization system. This paper proposes a simple method on the rotational motion estimation for the stabilization of the sight system.

In this paper, a dual level access scheme is proposed to provide two levels of access to the broadcast data; one to video signals protected for authorized users, another to extra information e.g. advertisements provided for the remaining users in the network. In the scheme, video signals in MPEG format are considered. The video contents are protected from unauthorized viewing by encrypting the DC coefficients of the luminance component in I-frames, which are extracted from the MPEG bit-stream. An improved direct sequence spread spectrum technique is used to add extra information to non-zero AC coefficients, extracted from the same MPEG bit-stream. The resultant MPEG bit-stream still occupies the same existing bandwidth allocated for a broadcast channel. At the receiver, the extra information is recovered and subtracted from the altered AC coefficients. The result is then combined with the decrypted DC coefficients to restore the original MPEG bit-stream. The experimental results show that less than 2.9% of the size of MPEG bit-stream was required to be encrypted in order to efficiently reduce its commercial value. Also, on average, with a 1.125 Mbps MPEG bit-stream, an amount of extra information up to 1.4 kbps could be successfully transmitted, while the video quality (PSNR) was unnoticeably degraded by 2.81 dB.

This letter presents an image rectification scheme that can be used by any image watermarking algorithms to provide robustness against rotation, scaling and translation (RST) transformations.

Compared with much research in the spatial-domain and transform-domain watermarking techniques, VQ-based watermarking technique has not been fully treated. A digital image watermarking scheme based on vector quantisation (VQ) is proposed to improve the degree of spreading watermark information. By partitioning the codebook into 3 groups, the scheme tries to embed one binary information for each block. The scheme spreads the watermark information almost evenly over the image with little extra distortion. The experimental results prove the efficiency and effectiveness of the scheme.

In this paper, we discuss digital watermarking techniques besed on modifying the spectral coefficient of an image, classified into quantization-based and correlation-based watermarking techniques. We first present a model of the watermark embedding and extracting processes and examine the robustness of the watermarking system against common image processing. Based on the result, we clarify the reason why detection errors occur in the watermark extracting process and give a method for evaluating the performance of the watermarking system. And then we study an improvement of the watermark extracting process using the deconvolution technique and present some concluding remarks in the last section.

This paper focuses on the watermarking system using a controlled quantization process. We first present a model of the watermark embedding and extracting processes and carry out their analyses. Then we examine the robustness of the watermarking system against common image processing and clarify the reason why detection errors occur in the watermark extracting process. Based on the result, we improve the watermark extracting process and design robust watermarking systems. The improvement is accomplished using a deconvolution filter and neural network techniques. Numerical experiments using the DCT-based watermarking system show good performance as expected by us.

In this paper, we propose a new watermarking method which spreads an ID pattern with specific sequences and embeds it throughout the spatial domain of an image. A set of the sequences is a key for extracting the ID pattern. As an ID pattern is spread throughout an image, we can extract the ID pattern from a part of the image, that is a clipped image. We can also confirm authenticity by extracting the same ID pattern from several parts of an image. The proposed method is robust to StirMark, which is a benchmark tool to test robustness of watermarked images, as well as disturbance by noise addition and common image processing operations such as edge-enhancement, brightness-contrast conversion, posterization, Gauss filtering, median filtering, gamma correction, JPEG compression and clipping.

Recently, digital contents are copied easily because of the development of digital technology. So digital watermark technique which aims at copyright protection of digital contents becomes more and more important, and various watermarking methods have been proposed. In this paper, we proposed a method of digital watermark for still image by using wavelet packets, and examine the robustness of the watermarking method against several image processings. This method can be easily applied to the watermark for video because in this method, embedded data are detected without original image. Therefore, we extend the wavelet-based watermarking method to the case of watermark for video.

Surface damage of the electrical contact is a primary cause of failure in many electronic devices which use sliding contacts. Therefore, the quantitative observation of the contact surface is one of the most important subjects for improvement of contact reliability. In this study, in order to clarify the relationship between the contact resistance and the damage on the contact surface, a digital image measuring system (DIMS) was developed. A shadow image processing technique (SIPT) was applied to the damage analysis on the sliding contact surface. The damage width on the contact surface and the damaged image could be obtained with a 3-D graphic image by applying both DIMS and SIPT. Part of the relationship between the damage on the contact surface and the contact resistance could be obtained in the case when Cu is used for the moving contact and Cu and Ni are used for the static contact.

This paper proposes a human interface where a novel input method is used to substitute conventional input devices. It overcomes the deficiencies of physical devices, as it is based on image processing techniques. The proposed interface is composed of three parts: extraction of a person's handshape from a digitized image, detection of its fingertip, and interpretation by a software application. First, images of a pointing hand are digitized to obtain a sequence of monochrome frames. In each frame the hand is isolated from the background by means of gray-level slicing; with threshold values calculated dynamically by the combination of movement detection and histogram analysis. The advantage of this approach is that the system adapts itself to any user and compensates any changes in the illumination, while in conventional methods the threshold values are previously defined or markers have to be attached to the hand in order to give reference points. Second, once the hand is isolated, fingertip coordinates are extracted by scanning the image. Third, the coordinates are inputted to an application interface. Overall, as the algorithms are simple and only monochrome images are used, the amount of processing is kept low, making this system suitable to real-time processing without needing expensive hardware.

The Institute for Posts and Telecommunications Policy (IPTP) held its first character recognition competition in 1992 to ascertain the present status of ongoing research in character recognition and to find promising algorithms for handwritten numerals. In this paper, we report and analyze the results of this competition. In the competition, we adopted 3-digit handwritten postal code images gathered from live mail as recognition objects. Prior to the competition, 2,500 samples (7,500 characters) were distributed to the participants as traning data. By using about 10,000 different samples (29,883 characters), we tested 13 recognition programs submitted by five universities and eight manufacturing companies. According to the four kinds of evaluation criteria: recognition accuracy, recognition speed, robustness against degradation, and theroretical originality, we selected the best three recognition algorithms as the Prize of Highest Excellence. Interestingly enough, the best three recognition algorithms showed considerable diversity in their methodologies and had very few commonly substituted or rejected patterns. We analyzed the causes for these commonly substituted or rejected patterns and, moreover, examined the human ability to discriminate between these patterns. Next, by considering the complementary characteristics of each recognition algorithm, we studied a multi-expert recognition strategy using the best three recognition algorithms. Three kinds of combination rules: voting on the first candidate rule, minimal sum of candidate order rule, and minimal sum of dissimilarities rule were examined, and the latter two rules decreased the substitution rate to one third of that obtained by one-expert in the competition. Furthermore, we proposed a candidate appearance likelihood method which utilizes the conditional probability of each of ten digits given the candidate combination obtained by each algorithm. From the experiments, this method achieved surprisingly low values of both substitution and rejection rates. By taking account of its learning ability, the candidate appearance likelihood method is considered one of the most promising multi-expert systems.

We apply neural networks to implement a line shape recognition/classification system. The purpose of employing neural networks is to eliminate target-specific algorithms from the system and to simplify the system. The system needs only to be trained by samples. The shapes are captured by the following operations. Lines to be processed are segmented at inflection points. Each segment is extended from both ends of it in a certain percentage. The shape of each extended segment is captured as an approximate curvature. Curvature sequence is normalized by size in order to get a scale-invariant measure. Feeding this normalized curvature date to a neural network leads to position-, rotation-, and scale-invariant line shape recognition. According to our experiments, almost 100% recognition rates are achieved against 5% random modification and 50%-200% scaling. The experimental results show that our method is effective. In addition, since this method captures shape locally, partial lines (caused by overlapping etc.) can also be recognized.

It is known that the resolution conversion based on orthogonal transform has a problem that is difference of luminance between the converted image and the original. In this paper, the scale factor of the system employing various orthogonal transforms is generally formulated by considering the DC gain, and the condition of alias free for DC component is indicated. If the condition is satisfied, then the scale factor is determined by only the basis functions.