J. Tsujiuchi

Color image correlation

Abstract A formulation for color image correlation is proposed. After suitable image transformations the correlator is capable of discriminating between images according to their color as well as their spatial information. A few examples are shown and some applications are suggested.

Multiplex holograms of a skull made of CT images

Abstract A multiplex hologram is sythesized from a series of CT (computer-aided tomogram) sectional images of the head of a patient taken with a small interval along the body axis. To show a skull shape in three dimensions through a synthesized hologram, images of the skull are first extracted by level slicing. Then, these images are transformed into a series of projected images and each view of different direction around the body axis is successively reconstructed and transformed into a hologram. The 3D shape of the skull is fairly well reconstructed by the synthesized hologram.

Digital processing of endoscopic color images

Abstract A basic concept is shown of color image processing such as color emphasis, contrast enhancement, and resolution improvement without destroying the color balance. An application to bronchus images taken through a fiber endoscope is also presented. The main purpose of this application is to make it easier to detect cancers on the bronchus surface by, for example, emphasizing small blood vessels.

Solvent vapour method in thermoplastic photoconductor media

The solvent vapour method, which uses solvent vapour to soften a plastic layer, has been developed in order to improve many defects originating in the Joules heat of the usual heating method. The behavior of charge carriers in the thermoplastic-photoconductor system has been studied and the following are found. First, the sensitivity and the maximum diffraction efficiency have been improved. Secondly, the electron cannot be injected from a transparent conductor layer to a photoconductor layer, but the electron can be injected in the heating method. Thirdly, the minus electrification is better than the plus electrification; however, the contrary result is given in the heating method. Finally the PLA effect is not observed so well.

A method of distortion compensation of multiplex holograms

Abstract A new method for making distortion-free multiplex holograms is proposed. The original images of them are processed by a computer to cancel the distortion of the final image. Examples of the reconstructed images are also presented.

An improved technique for holographic recording on thermoplastic-photoconductor (II)

Abstract An improved technique (PLA method) for holographic recording on thermoplastic-photoconductor has three main features: higher amplification, a wider spatial frequency range of recording and improved reciprocity. Research has been carried out to explain these features. It was found that a stronger deformation force, finer frost, memory effect and edge effect are involved in explaining these features.

Holography of 3d Surface Reconstructed Ct Images

A multiplex hologram (cylindrical holographic stereogram) was successfully made from three-dimensional (3D) surface reconstruction CT images of a child with plagiocephaly. This method appears to be suitable as one of the projectional aids of 3D surface reconstruction CT images that are proving useful in plastic and reconstructive surgery. The principle of the method is described. Also discussed is the possibility of developing a computer-aided hologram synthesizing system that could be used for images obtained with U-arm X-ray equipment (by either cinefilm, or videotape, or digital subtraction angiography) or by CT as well as MR. For practical use, it is necessary for the hologram to be synthesized in a short time. One of the key problems in developing such a machine is the need for an incoherent-to-coherent image converter.

Synthesis Of Multiplex Holograms And Their Application To Medical Objects

A multiplex hologram is synthesized by using a special optical system from an original film composed of a series of conventional photographs taken from different horizontal directions. An automatic apparatus for synthesizing multiplex holograms is built and fundamental properties of reconstructed images such as distortion and resolution are studied for both ordinary and medical objects. Some techniques to compensate the distortion are developed.

Image blur of multiplex holograms

Abstract The image blur of multiplex holograms is discussed by considering the reconstruction of a point object, and it is derived that influences of the vertical length of the illuminating light source are more serious than the case of rainbow holograms. Some examples are presented by calculation and experiments.

An experiment of image-subtraction using holographic beam splitter

Abstract A holographic beam splitter is applied to a two-beam interferometer for the purpose of the complex image subtraction. The two-beam interferometer with this beam splitter can be constructed without requiring the components of the optical system to be of a high quality and a “more-than-three-beam” interferometer can be realized.