Showing papers by "Jumpei Tsujiuchi published in 1988"
TL;DR: A pseudo-3-D surface reconstruction of the gastric surface by mapping the endoscopic image onto the retrieved elevation information is proposed, and some results of stereopair matching with color image correlation are presented.
Abstract: We propose finding an optimal generalized color plane to carry out digital color image correlation. We seek the optimization of the correlation peak’s sharpness and, for the purpose of analysis, we make some assumptions regarding the statistical properties of images to be considered. The analysis leads to a simple solution involving a projection onto the Karhunen-Loeve vectors corresponding to the smallest eigenvalues of the interprimary colors covariance matrix. We use our results in the retrieval of the gastric mucosal surface structure from stereopairs taken through an endoscope. Study of the statistics of the endoscope images shows that the assumptions used earlier can be applied to this type of image. We present some results of stereopair matching with color image correlation. We conclude by proposing a pseudo-3-D surface reconstruction of the gastric surface by mapping the endoscopic image onto the retrieved elevation information.
30 citations
TL;DR: In this article, it was shown that the phase of a reference wave can be determined by using a Fourier analysis in a continuous space, and the accuracy of the phase determination was analyzed in case of additive noise.
Abstract: In the fringe-scanning methods such as the three- and four-bucket methods, the phase of a reference wave is generally changed at equal intervals from 0 to 2π. In practice, however, it is difficult or almost impossible for some interferometers, such as the dynamic zone plate interferometer, to realize an equal phase shift and to make a full scanning of 2π, which are necessary for discrete Fourier transform analysis. We show that even in such a case, phases in an interferogram can be obtained by using a Fourier analysis in a continuous space, and we analyze the accuracy of the phase determination in case of additive noise.
28 citations
TL;DR: A fringe scanning scatter plate interferometer, which uses a polarized light to achieve the required phase shift between the reference and test beam, is described in this article, where the authors also describe a particle filter.
23 citations
TL;DR: A least-squares filter for restoration of blurred color images was developed directly from spectral and spatial correlations and on the basis of a mathematical model that assumes that spectroscopic images of an object are specified by spectral vectors and that a set of such orthonormal vectors forms a multidimensional color space.
Abstract: A least-squares filter for restoration of blurred color images was developed directly from spectral and spatial correlations and on the basis of a mathematical model that assumes that spectroscopic images of an object are specified by spectral vectors and that a set of such orthonormal vectors forms a multidimensional color space. Primary colors are expressed by a linear combination of spectral vectors, and color images are given by the projection of spectroscopic images onto the primary color or observation vectors. Detailed discussions and a computer simulation are presented.
21 citations
TL;DR: It is shown that the formulation not only provides us with a spatial/spectral recognition filter but also reduces to an easily implemented prefiltering operator which increases selectivity, much like high-pass filtering.
21 citations
15 Jan 1988
TL;DR: In this article, the fundamental properties of reconstructed images from a multiplex hologram are studied, and conditions for compensating distortions and for designing a reconstructing source are proposed for medical objects.
Abstract: Fundamental properties of reconstructed images from a multiplex hologram are studied, and conditions for compensating distortions and for designing a reconstructing source are proposed. Applications of multiplex hologram to medical objects are reviewed, and a computer-aided hologram synthesizing system is proposed for obtaining better images and wider applications. An example of multiplex holograms synthesized from a series of CT images is also presented.
9 citations
TL;DR: In this article, a simple interferometric method is proposed for constructing equispaced circular gratings, which uses only a cylindrical mirror and a collimating lens, and the radial spatial frequency of the gratings thus constructed is a function of the focal length of the collimation lens.
6 citations
TL;DR: In this paper, a new method for fringe pattern analysis is proposed, which needs the introduction of defocusing into the fringe patern, and the fringe pattern with defocusing is analyzed using a 2D Fresnel transform.
6 citations