Yoshizumi Yasuda

Computer-Aided Diagnostic System For Mass Survey Chest Images

In order to support screening of chest radiographs on mass survey, a computer-aided diagnostic system that automatically detects abnormality of candidate images using a digital image analysis technique has been developed. Extracting boundary lines of lung fields and examining their shapes allowed various kind of abnormalities to be detected. Correction and expansion were facilitated by describing the system control, image analysis control and judgement of abnormality in the rule type programing language. In the experiments using typical samples of students radiograms, good results were obtained for the detection of abnormal shape of lung field, cardiac hypertrophy and scoliosis. As for the detection of diaphragmatic abnormality, relatively good results were obtained but further improvements will be necessary.

Design of Optimal LUT in Color-Reproduction of Dots Printer

Recently, digital hard copy machines have drawn a great attention because they have good performance of signal processing. Hard copies are directly obtained from video signal by connecting CRT monitor and digital hard copy machine. At that time, many signal processing are considered to produce the desired images. In the color reproduction process, the processing technique that can reproduce saturated and luminous color of CRT monitor by using color ink must be considered, because the color gamut of CRT color monitor is wider than the one that uses in ink for printing purpose. This paper proposes a method of color rearrangment along the constant hue locus to produce correctly the hue of the colors that exist between the ink gamut and CRT gamut. And then, it is shown that the effect is observed clearly in red comparing to the usual color rearrangment.

Optical design of airborne imaging spectrometer

Optical design of Air.bone liaging Spectroieter is described in this study. A new design of push.brooi type liaging Spectroseter using lens, prisa and CCD sensor systei is cospared to classical Isaging Spectrometers those were composed of all reflecting optical components. Advantage of using refracting elements against that of using mirror and reflection grating is the design flexibility of optical components and possibility of reducing and correcting many kind of aberrations. Disadvantage of lens system - chromatic aberration - is reduced to be negligibly small within 0.4 to 1.0 jim by selecting glass materials. The purpose of Imaging pectrometer is to monitor life conditions of vegetations from high altitudes by measuring spectral reflectance of foliage (chiorophyl). By such purpose, wavelength was limited from visible until near IR region.

Spectrum Analysis of the Sea Waves Using Coherent Optical System

The objective of the study is an analysis of the sea waves by the way of a combination with an aerial photography and a coherent optical system. The coherent optical system has been arranged to make a good divide of low frequency spectra by improving the system arrangement because sea waves in an aerial photography have generally slow variations. The direction and the wave length limits in the four properties of the wave are decided simply and easily by this spectrum analysis using this coherent optical system.

Feasibility of Discriminating Tree Species and Tree Vigor by Chromaticity of Color Infrared Photography

The feasibility of the tree species discrimination and tree vigor discrimination were examined by using of Chromaticity measurement of IR color film.The chromaticity of color image was determined from measuring spectral transmit-tance by the microspectrophotometer, and displaied on the CIE 1960 UCS diagram.Discrimination was based on the differences of the chromaticities, and discriminant functions to discriminate tree species were obtained.The result shows that discrimination of tree species is relatively easy in the case of some tree combination, and that discrimination of the tree vigor gradation is not feasible, by the chromaticity measurements.