Showing papers by "Nagaaki Ohyama published in 1996"

Image processing apparatus using correlation among images

Abstract: An image processing apparatus comprises a CPU, an information input unit, a main storage made up of a RAM, an image input interface, a display interface, and a ROM. These components are mutually connected on a bus. The CPU includes an image processor which operates according to programs stored in the ROM. The image processor comprises a corresponding point detector for detecting corresponding points in multiple images, an image matching unit for matching at least two images according to the output result of the corresponding point detector, and an image synthesizer for synthesizing at least part of at least one image portion matched by said image matching unit with at least part of image information of other images to form a single image. The information input unit is a keyboard for entering the type of an electronic endoscope and other data. The image input interface is connected to image memories and receives image data from the memories.

Color image recording and reproducing system

Abstract: A spectral image photographing section photographs the image of an object to be photographed as spectrum information in units of pixels so as to mutually record and reproduce a faithful image between two points. A photographing light spectrum detecting section detects the spectrum distribution of illumination light at a photographing point. A reproduction environment light spectrum detecting section detects the spectrum distribution of illumination light at a reproduction point. A spectral reflectance distribution calculating section eliminates the influence of the spectrum distribution of illumination light from the spectrum information photographed by the spectral image photographing section, and calculates the spectral reflectance distribution of the object. A spectrum converting section calculates, on the basis of the reproduction environment light spectrum detected by the reproduction environment light spectrum detecting section and the spectral reflection distribution calculated by the spectral reflectance distribution calculating section, a spectrum distribution obtained when the image of the object is photographed under illumination light substantially identical to that at the reproduction point. A vector imaging section converts the spectrum distribution of each pixel converted by the spectrum converting section into three-dimensional color.

Optical image reconstructing apparatus capable of reconstructing optical three-dimensional image having excellent resolution and S/N ratio

Abstract: An optical image reconstructing apparatus includes an optical image forming system. A focused surface controller moves the position of an object surface focused by the optical image forming system. An image pickup converts an image of an object formed by the optical image forming system into an electrical signal and outputs the electrical signal as an image signal. An adder adds a plurality of image signals output from the image pickup while the position of the object surface is moved by the focused surface controller. A frequency filtering device performs a frequency filtering operation on an image signal outputted from the adder to produce a filtered image signal. A rotation controller rotates the object or the optical image forming system at a predetermined angular interval around one point on an optical axis of the optical image forming system. An image synthesizing device performs interpolation on a plurality of filtered image signals output from the frequency filtering device while the object or the optical image forming system is rotated at the predetermined angular interval by the rotation controller, to synthesize images in a surface direction parallel to a rotation control surface of the rotation controller, thereby preparing a reconstructed three-dimensional image.

High‐speed recording of full‐parallax holographic stereograms by a parallel exposure system

Abstract: A full-parallax holographic stereogram, which is suitable for the holographic 3-D printer (holoprinter), is being developed for the output device of three-dimensional (3-D) image hard copies of computer data. A new optical system of the holoprinter for high-speed printing is presented. The new optical system realizes the parallel exposure of elementary holograms using an array of small lenses and reduction optics. In the experiment, 12 elementary holograms were simultaneously exposed by each exposure, and the printing speed became about 10 times faster than the previous experiments, since each exposure time was almost equivalent to the case of the conventional single exposure. The effect of the alignment error of the lens array is also described.

Microscopic Computed Tomography Based on Generalized Analytic Reconstruction from Discrete Samples

Abstract: We propose a computed tomography (CT) for the incoherent optical system based on a generalized analytic reconstruction method from discrete samples (GARDS), by which an object image defined in a continuous space is reconstructed from discrete images acquired through the imaging system. We apply this method to reconstruct depth structures of micro-specimens using conventional fluorescence microscopes. Also, we discuss the optimal sampling distance in the depth direction through a generalized singular value decomposition of a continuous-to-discrete imaging system. We next apply the GARDS-based CT method to a double-axis microscope, in which two microscopes are set up perpendicularly to cover a missing frequency band of each microscopic imaging system. We show simulation results which verify the effectiveness of our proposed method.

Three-dimensional computed tomography using a double-axis fluorescence microscope

Abstract: We developed a double-axis fluorescence microscope as a new type of 3D microscope, in which two conventional microscopes are placed perpendicularly to one another. This optical microscope provides a solution to extend the spatial frequency band in the depth direction, which is greatly limited for conventional single-axis microscopes. In addition, this equipment has a capability of implementing a fast image acquisition system by simultaneously taking images through both microscopes. We evaluated the 3D imaging properties of our system using 3D observation images of a micro-fluorescent sphere. In order to reconstruct 3D images of micro-objects, we applied a CT-based method we proposed to the 3D microscopic imaging system. Our experiments using a biological micro-specimen verified usefulness and effectiveness of our system.