Author
T. Honda
Bio: T. Honda is an academic researcher from Tokyo Institute of Technology. The author has contributed to research in topics: Aperture & Image restoration. The author has an hindex of 2, co-authored 4 publications receiving 28 citations.
Papers
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TL;DR: In this article, a special scanning aperture with a circular shape and ten concentric rings with equal separation was used to restore the defocused point-spread function of a single image.
Abstract: Defocused pictures are restored by the convolution operation with a special scanning aperture. The scanning aperture has a circular shape with an extent smaller than twice that of the defocused point-spread function, and is divided into ten concentric rings with equal separation. The restoration experiment is executed using a digital computer image-processing system, and some experimental results evaluating the effectiveness of the aperture are described.
14 citations
TL;DR: The restoration of one-dimensional linear blur is taken as an example, and methods of designing the aperture array and evaluating its performance are discussed.
Abstract: An approach to image processing is made by means of image scanning with an aperture array. The restoration of one-dimensional linear blur is taken as an example, and methods of designing the aperture array and evaluating its performance are discussed. The quality criterion of restored images with regard to resolution and detection is introduced and applied to the practical system.
11 citations
TL;DR: In this paper, the effects of the operation range of convolution and of the width of a segment in the aperture upon the restoration of linear motion blurring by the convolution method, realized by scanning a picture to be processed with an aperture of special form, is considered.
Abstract: The restoration of linear-motion blurring by the convolution method, realized by scanning a picture to be processed with an aperture of special form, is considered. Effects of the operation range of convolution and of the width of a segment in the aperture upon the restoration are discussed. The influence of noise in restoration processing with typical apertures is also discussed.
2 citations
TL;DR: The amount of motion in a linear motion blurred picture is estimated by finding the spatial frequency where the power spectrum of the blurred picture, calculated by a digital computer, shows a minimum value.
Abstract: The amount of motion in a linear motion blurred picture is estimated by finding the spatial frequency where the power spectrum of the blurred picture, calculated by a digital computer, shows a minimum value. Influences of the structure of the original pattern and the noise added in recording blurred pictures to the estimation of the motion blur are also discussed.
1 citations
Cited by
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29 Feb 1980
TL;DR: This paper reviews these methods for performing bipolar spatial filtering operations with incoherent optical systems, and, to a limited extent, compares them.
Abstract: In this chapter we have analyzed the basic characteristics of incoherent optical processing, considering three major classes of systems: (1) systems that rely on diffraction; (2) systems that rely on plane-to-plane imaging in the geometrical optics sense; and (3) systems that rely on diffractionless geometrical optics “shadow casting” for their operation. Incoherent systems are often characterized by a redundancy and immunity to noise not associated with coherent optical systems. However, the non-negative real nature of the information-bearing irradiance distributions precludes direct implementation of incoherent systems in many signal processing applications, and various tricks must be employed. Dynamic range limitations with incoherent systems are an area of active study, and the relative advantages of incoherent systems over coherent systems are not known conclusively.
30 citations
TL;DR: A new digital method of superresolution or restoration of band-limited images in the presence of noise is described, an iterative regularized pseudoinverse (RPI) algorithm that is based on the principle of least squares that acquires the advantage of tolerance to noise.
Abstract: We describe a new digital method of superresolution or restoration of band-limited images in the presence of noise. The restoration procedure is an iterative regularized pseudoinverse (RPI) algorithm that is based on the principle of least squares. This method acquires the advantage of tolerance to noise by incorporating additional constraints of nonnegativity of the object and adaptive regularization as well as the finite extent of the object. After discussing the convergence of the iterative RPI algorithm, we present some results of computer simulations that demonstrate the effectiveness of the proposed method.
21 citations
TL;DR: A time selection technique is described which has been employed to correct for the image wandering using multiple frame image sequences and is mathematically analyzed and demonstrated experimentally with a sequence of images of an underwater bar.
20 citations
TL;DR: In this article, the angular selectivity of volume diffraction gratings is exploited to form a spatial-frequency filter, which is recorded in a thick recording medium as a superposition of several simple gratings or as a single grating with a modulation that varies in depth.
Abstract: The angular selectivity of volume diffraction gratings is exploited to form a spatial-frequency filter. The filter is recorded in a thick recording medium as a superposition of several simple gratings or as a single grating with a modulation that varies in depth. Such a device can have controlled angular selectivity so as to alter the relative amplitude and phase of selected spatial-frequency components. A coupled-wave formalism is used to analyze the angular selectivity of this device and experimental results demonstrate its usefulness in improving motion-blurred images.
15 citations
TL;DR: In this article, a special scanning aperture with a circular shape and ten concentric rings with equal separation was used to restore the defocused point-spread function of a single image.
Abstract: Defocused pictures are restored by the convolution operation with a special scanning aperture. The scanning aperture has a circular shape with an extent smaller than twice that of the defocused point-spread function, and is divided into ten concentric rings with equal separation. The restoration experiment is executed using a digital computer image-processing system, and some experimental results evaluating the effectiveness of the aperture are described.
14 citations