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240,000 participants have a screening for diagnosis of pneumoconiosis every year in Japan. Radiograph is used for staging of severity in pneumoconiosis worldwide. This paper presents a method for quantitative assessment of severity in pneumoconiosis using both size and frequency of lung nodules that detected by thin-section CT images. This method consists of three steps. First, thoracic organs (body, ribs, spine, trachea, bronchi, lungs, heart, and pulmonary blood vessels) are segmented. Second, lung nodules that have radius over 1.5mm are detected. These steps used functions of our developed computer aided detection system of chest CT images. Third, severity in pneumoconiosis is quantified using size and frequency of lung nodules. This method was applied to nine pneumoconiosis patients. The initial results showed that proposed method can assess severity in pneumoconiosis quantitatively. This paper demonstrates effectiveness of our method in diagnosis and prognosis of pneumoconiosis in CT screening.

In this paper we propose a multispectral image compression based on lossy to lossless coding, suitable for both spectral and color reproduction. The proposed method divides a multispectral image data into two groups, RGB and residual. The RGB component is extracted from the multispectral image, for example, by using the XYZ Color Matching Functions, a color conversion matrix, and a gamma curve. The original multispectral image is estimated from RGB data encoder, and the difference between the original and the estimated multispectral images, referred as a residual component in this paper, is calculated in the encoder. Then the RGB and the residual components are encoded by JPEG2000, respectively a progressive decoding is possible from the losslessly encoded code-stream. Experimental results show that, although the proposed method is slightly inferior to JPEG2000 with a multicomponent transform in rate-distortion plot of the spectrum domain at low bit rate, a decoded RGB image shows high quality at low bit rate with primary encoding of the RGB component. Its lossless compression ratio is close to that of JPEG2000 with the integer KLT.

One of the key issues in establishing an optical fiber sensing system based on fiber Bragg gratings (FBGs) is the selection of a suitable wavelength shift detection scheme in terms of the performance it offers. By use of a compact Fabry-Perot (F-P) tunable filter, the Bragg wavelength variation can be detected with a relatively high speed and satisfying resolution. In this paper, a dynamic strain sensing system based on F-P tunable filter is described, and the F-P tunable filter is demonstrated to have a significant impact on the system. The relationship between the collected spectrum of grating and the 3-dB bandwidth of the F-P tunable filter is discussed. The optimum 3-dB bandwidth of the F-P tunable filter for most FBGs is obtained. It is exhibited in this paper that the demodulation precision and sensitivity of the strain sensing system is influenced by the nonlinearity between the transmission wavelength of the F-P tunable filter and the drive voltage. The drive voltage is rectified using interpolation algorithm. The experimental results illustrate that the average error and the maximum error of the transmission wavelength are decreased by 96.4% and 80.9% respectively. The strain sensitivity of the optimized system is below 3μe. The error between the practical strain value demodulated by the system and theoretical value is below 5%.

This paper presents experimental results of a static aberration control algorithm based on the linear relation be- tween mean square of the aberration gradient and the second moment of point spread function for the generation of control signal input for a deformable mirror (DM). Results presented in the work of Yang et al.1 suggested a good feasibility of the method for correction of static aberration for point and extended sources. However, a practical realisation of the algorithm has not been demonstrated. The goal of this article is to check the method experimentally in the real conditions of the present noise, finite dynamic range of the imaging camera, and system misalignments. The experiments have shown strong dependence of the linearity of the relationship on image noise and overall image intensity, which depends on the aberration level. Also, the restoration capability and the rate of convergence of the AO system for aberrations generated by the deformable mirror are experi- mentally investigated. The presented approach as well as the experimental results finds practical application in compensation of static aberration in adaptive microscopic imaging system.

Criminal activity in virtual worlds is becoming a major problem for law enforcement agencies. Forensic investigators are becoming interested in being able to accurately and automatically track people in virtual communities. In this paper a set of algorithms capable of verification and recognition of avatar faces with high degree of accuracy are described. Results of experiments aimed at within-virtual-world avatar authentication and inter-reality-based scenarios of tracking a person between real and virtual worlds are reported. In the FERET-to-Avatar face dataset, where an avatar face was generated from every photo in the FERET database, a COTS FR algorithm achieved a near perfect 99.58% accuracy on 725 subjects. On a dataset of avatars from Second Life, the proposed avatar-to-avatar matching algorithm (which uses a fusion of local structural and appearance descriptors) achieved average true accept rates of (i) 96.33% using manual eye detection, and (ii) 86.5% in a fully automated mode at a false accept rate of 1.0%. A combination of the proposed face matcher and a state-of-the art commercial matcher (FaceVACS) resulted in further improvement on the inter-reality-based scenario.

This paper proposes a robust ear identification system which is developed by fusing SIFT features of color segmented slice regions of an ear. The proposed ear identification method makes use of Gaussian mixture model (GMM) to build ear model with mixture of Gaussian using vector quantization algorithm and K-L divergence is applied to the GMM framework for recording the color similarity in the specified ranges by comparing color similarity between a pair of reference ear and probe ear. SIFT features are then detected and extracted from each color slice region as a part of invariant feature extraction. The extracted keypoints are then fused separately by the two fusion approaches, namely concatenation and the Dempster-Shafer theory. Finally, the fusion approaches generate two independent augmented feature vectors which are used for identification of individuals separately. The proposed identification technique is tested on IIT Kanpur ear database of 400 individuals and is found to achieve 98.25% accuracy for identification while top 5 matched criteria is set for each subject.

The availability of reliable silicon-based laser sources is at the basis of the integration of photonic and microelectronic devices on a single chip with consequent development of wavelength division multiplexing telecommunication systems. A high efficiency Si-based laser source with good stability at room temperature would encourage and push the large scale of integration of electronic and photonic devices within a single chip. Several techniques have been proposed for generating light with an internal quantum efficiency some order of magnitude greater than that typical of silicon (10-6) by using either electrical or optical pumping. Among them we mention the improvement of some fabrication process steps, reduction of the channels of non-radiative recombination, quantum confinement, the use of silicon nanocrystals (Si-ncs) incorporated in a silica matrix. This last technique is used in combination with Er3+ doping to generate light emission around 1500 nm in silicon, since Er-doped Si-ncs behave as electron-hole pairs trap, and the presence of Er shifts the emission peak to around 1500 nm. In this paper we have pointed out the optical model of a Si-based DBR laser including a Si-ncs Er-doped SiO2 rib waveguide, working at a wavelength in C-band. In particular, after a brief description of the structural and optical properties of the silicon crystals, we report on the model and design of the Er:Si-nc/SiO2 rib waveguide, of the optical cavity and of the Bragg mirrors. Numerical results are in good agreement with the literature.

Polar orbiting satellites with low spatial resolution sensors, such as the AVHRR, provide repeated global coverage of the Earth. The data is directly transmitted to ground stations, and in some cases distributed immediately after the data acquisition. Near real time applications can be implemented if the adequate processing tools are available. This paper presents a near real time processing system, developed for NOAA/AVHRR data acquired from the Dundee satellite station. The system performs image calibration, geometric corrections and atmospheric corrections with minimum operator intervention. The geometric corrections consist of an orbital-based correction refined by the automatic identification of Ground Control Points (GCPs) by image matching. The atmospheric correction is based on simulations performed on the 6S radiative transfer code using a set of typical and expected values for the most significant parameters. An attempt to evaluate the error associated with the simplified atmospheric correction method was carried out. As an illustration, 3 AVHRR images from NOAA 16 were processed. The ranges of values encountered for the most relevant parameters were analyzed. The range and average values for the reflectance channels 1 and 2 with and without the atmospheric correction are compared. These were used to produce standard Normalized Difference Vegetation Index (NDVI) images and atmospheric corrected NDVI images.

Industrial, military, medical, and research and development applications of lasers frequently require a beam with a specified irradiance distribution in some plane. A common requirement is a laser profile that is uniform over some cross-section. Such applications include laser/material processing, laser material interaction studies, fiber injection systems, optical data image processing, lithography, medical applications, and military applications. Laser beam shaping techniques can be divided into three areas: apertured beams, field mappers, and multi-aperture beam integrators. An uncertainty relation exists for laser beam shaping that puts constraints on system design. In this paper the authors review the basics of laser beam shaping and present applications and limitations of various techniques.

Automated distinction of medical images is an important preprocessing in Computer-Aided Diagnosis (CAD) systems. The CAD systems have been developed using medical image sets with specific scan conditions and body parts. However, varied examinations are performed in medical sites. The specification of the examination is contained into DICOM textual meta information. Most DICOM textual meta information can be considered reliable, however the body part information cannot always be considered reliable. In this paper, we describe an automated distinction of DICOM images as a preprocessing for lung cancer CAD system. Our approach uses DICOM textual meta information and low cost image processing. Firstly, the textual meta information such as scan conditions of DICOM image is distinguished. Secondly, the DICOM image is set to distinguish the body parts which are identified by image processing. The identification of body parts is based on anatomical structure which is represented by features of three regions, body tissue, bone, and air. The method is effective to the practical use of lung cancer CAD system in medical sites.

We have developed an anonymization system for DICOM images. It requires consent from the patient to use the DICOM images for research or education. However, providing the DICOM image to the other facilities is not safe because it contains a lot of personal data. Our system is a server that provides anonymization service of DICOM images for users in the facility. The distinctive features of the system are, input interface, flexible anonymization policy, and automatic body part identification. In the first feature, we can use the anonymization service on the existing DICOM workstations. In the second feature, we can select a best policy fitting for the Protection of personal data that is ruled by each medical facility. In the third feature, we can identify the body parts that are included in the input image set, even if the set lacks the body part tag in DICOM header. We installed the system for the first time to a hospital in December 2005. Currently, the system is working in other four facilities. In this paper we describe the system and how it works.