A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

An intelligent electronic appliance preferably includes a user interface, data input and/or output port, and an intelligent processor. A preferred embodiment comprises a set top box for interacting with broadband media streams, with an adaptive user interface, content-based media processing and/or media metadata processing, and telecommunications integration. An adaptive user interface models the user, by observation, feedback, and/or explicit input, and presents a user interface and/or executes functions based on the user model. A content-based media processing system analyzes media content, for example audio and video, to understand the content, for example to generate content-descriptive metadata. A media metadata processing system operates on locally or remotely generated metadata to process the media in accordance with the metadata, which may be, for example, an electronic program guide, MPEG 7 data, and/or automatically generated format. A set top box preferably includes digital trick play effects, and incorporated digital rights management features.

Intelligent electronic appliance system and method

An adaptive interface for a programmable system, for predicting a desired user function, based on user history, as well as machine internal status and context. The apparatus receives an input from the user and other data. A predicted input is presented for confirmation by the user, and the predictive mechanism is updated based on this feedback. Also provided is a pattern recognition system for a multimedia device, wherein a user input is matched to a video stream on a conceptual basis, allowing inexact programming of a multimedia device. The system analyzes a data stream for correspondence with a data pattern for processing and storage. The data stream is subjected to adaptive pattern recognition to extract features of interest to provide a highly compressed representation which may be efficiently processed to determine correspondence. Applications of the interface and system include a VCR, medical device, vehicle control system, audio device, environmental control system, securities trading terminal, and smart house. The system optionally includes an actuator for effecting the environment of operation, allowing closed-loop feedback operation and automated learning.

Ergonomic man-machine interface incorporating adaptive pattern recognition based control system

We define a new image feature called the color correlogram and use it for image indexing and comparison. This feature distills the spatial correlation of colors, and is both effective and inexpensive for content-based image retrieval. The correlogram robustly tolerates large changes in appearance and shape caused by changes in viewing positions, camera zooms, etc. Experimental evidence suggests that this new feature outperforms not only the traditional color histogram method but also the recently proposed histogram refinement methods for image indexing/retrieval.

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Image indexing using color correlograms

A self-scanned 1024 element photodiode array and minicomputer are used to measure the phase (wavefront) in the interference pattern of an interferometer to lambda/100. The photodiode array samples intensities over a 32 x 32 matrix in the interference pattern as the length of the reference arm is varied piezoelectrically. Using these data the minicomputer synchronously detects the phase at each of the 1024 points by a Fourier series method and displays the wavefront in contour and perspective plot on a storage oscilloscope in less than 1 min (Bruning et al. Paper WE16, OSA Annual Meeting, Oct. 1972). The array of intensities is sampled and averaged many times in a random fashion so that the effects of air turbulence, vibrations, and thermal drifts are minimized. Very significant is the fact that wavefront errors in the interferometer are easily determined and may be automatically subtracted from current or subsequent wavefrots. Various programs supporting the measurement system include software for determining the aperture boundary, sum and difference of wavefronts, removal or insertion of tilt and focus errors, and routines for spatial manipulation of wavefronts. FFT programs transform wavefront data into point spread function and modulus and phase of the optical transfer function of lenses. Display programs plot these functions in contour and perspective. The system has been designed to optimize the collection of data to give higher than usual accuracy in measuring the individual elements and final performance of assembled diffraction limited optical systems, and furthermore, the short loop time of a few minutes makes the system an attractive alternative to constraints imposed by test glasses in the optical shop.

Digital wavefront measuring interferometer for testing optical surfaces and lenses

An interferometric method for making equispaced circular gratings

A method is proposed in which the locations and electric current vectors of multiple biomagnetic current dipoles can be estimated without a priori information regarding the exact number of dipoles. In this method, an additional constraint is used in the cost function in conjunction with a constraint regarding degree of matching between estimated dipole parameters and a measured magnetic field. Two constraints, a constraint on the sum of current magnitude and that on the sum of each dipole's contribution on measured data, are proposed as the additional constraint in this paper. Computer simulation clearly shows that cither constraint can be effectively used to suppress the ambiguity caused by the lack of information regarding the exact number of dipoles. Since the cost function becomes highly nonlinear, the simulated annealing algorithm1,2 is essential to search for the minimum of the cost function.

Parameter estimation of multiple biomagnetic current dipoles using simulated annealing

Algebraic reconstruction methods have been successfully used to improve quality of positron emission tomography (PET) images by accurate modeling of measurement system, but they have computational burden The authors propose a fast PET image reconstruction method based on an algebraic technique In this method, reconstruction operators are pre-computed approximately using subsets of sensitivity functions The subsets contain the sensitivity functions that contribute significantly to each point to be reconstructed The proposed method was applied to simulated data and experimental data for the ECAT EXACT HR+ (Siemens/CTI) scanner operating in 2D mode These results show that the proposed method produces images with almost the same quality as the conventional algebraic methods do and has a similar computation time to the filtered backprojection method

Algebraic PET image reconstruction with pre-computed reconstruction operators using subsets of sensitivity functions

This paper shows a Fourier domain analysis of dual-sampling region-of-interest x-ray tomography and proposes a method to decrease the artifacts caused by the undersampling errors. Computer simulation is also presented.

Analysis and improvement in region-of-interest tomography

The architecture of 6-band HDTV camera system, which is newly developed for accurate color reproduction of motion picture based on spectral information is presented. The 6band HDTV camera is constructed by an optical system connecting the objective lens and two sets of conventional HDTV cameras whose spectral sensitivities are modified differently by interference filters inserted between the optical system and each camera. We evaluated the accuracy of the color estimations achieved by the 6-band and a conventional RGB (i.e. 3-band) HDTV camera. The evaluations are conducted using simulated camera signals and those obtained by experimental measurements. It is confirmed that the 6-band camera achieves the accurate color estimation for the use in extensive applications. In the experimental evaluation the average color difference of dEab obtained from the 6-band camera signals and the RGB camera signals became 1.43 and 4.12 respectively.

Nagaaki Ohyama

Papers

An interferometric method for making equispaced circular gratings

Parameter estimation of multiple biomagnetic current dipoles using simulated annealing

Algebraic PET image reconstruction with pre-computed reconstruction operators using subsets of sensitivity functions

Analysis and improvement in region-of-interest tomography

Six-Band HDTV Camera System for Color Reproduction Based on Spectral Information.