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

Filtered backprojection (FBP) method for positron emission tomography (PET) produces artifacts in the reconstructed images when the measurement system has the shift-variant characteristics. On the other hand, the conventional algebraic reconstruction methods, such as the generalized analytic reconstruction from discrete samples (CARDS), the natural pixel decomposition (NPD) and the algebraic reconstruction technique (ART), can correct these characteristics, while these methods have computational burden. Here, the authors propose a fast image reconstruction method for PET using an algebraic technique. In this method, a reconstruction operator is given approximately using subsets of sensitivity functions. The subsets are designed by selecting the sensitivity functions that have high sensitivity to each point to be reconstructed and by keeping an accuracy of the reconstructed images. The proposed method was applied to simulated data for the scanner, ECAT EXACT HR+ (Siemens/CTI) working in the 2D mode. This result shows that the proposed method produces images with almost the same quality as the conventional algebraic methods do and has a similar computation time to FBP method.

Fast algebraic reconstruction using subsets of PET data

To increase the detection efficiency and improve the spatial resolution, a coded-aperture imaging method is applied to nuclear medicine. The aperture consists of nine pinholes arranged in a square grid. Three kinds of coding are sequentially used to record the same number of projections including parallax and overlap. The overlapped images are partially separated, and good tomograms of a ring phantom and a human myocardium are reconstructed using a modified backprojection algorithm with variable damping factor.

Coded-aperture imaging system for reconstructing tomograms of human myocardium.

Compensation of color shift due to the multiple reflection of illumination in CCD endoscopic color measurement: (1) principle and basic experiment

Physical staining is indispensable in pathology. While physical staining uses chemicals, "digital staining" exploits the
differing spectral characteristics of the different tissue components to simulate the effect of physical staining. Digital
staining for pathological images involves two basic processes: classification of tissue components and digital
colorization whereby the classified tissue components are impressed with colors associated to their reaction to specific
dyes. Spectral features, i.e. spectral transmittance, of the different tissue structures are dependent on the staining
condition of the tissue slide. Thus, if the staining condition of the test image is different, classification result is affected,
and the resulting digitally-stained image may not reflect the desired result. This paper shows that it is possible to obtain
robust classification results by correcting the dye amount of each test-image pixel using Beer Lambert's Law. Also the
effectiveness of such technique to be incorporated to the current digital staining scheme is investigated as well.

Nagaaki Ohyama

Papers

Fast algebraic reconstruction using subsets of PET data

Coded-aperture imaging system for reconstructing tomograms of human myocardium.

Compensation of color shift due to the multiple reflection of illumination in CCD endoscopic color measurement: (1) principle and basic experiment

Digital staining of pathological images: dye amount correction for improved classification performance

New Method for Reproducing Fluorescent Colors.