Biomedical subjects

Tadashi Aruga

Publications and source records attributed to Tadashi Aruga.

3 recordsLinked to original sources

PubMed2005

Blurred image recovery by a phase-processing method with tilt correction.

We present an improved method that incorporates tilt correction for blurred image recovery. A previously proposed method, which can compensate image blurring due to atmospheric turbulence, was improved to increase recovered image quality by correcting the tilt effect resulting from, e.g., a telescope's tracking jitter. Real-image analysis based on data from a 1.5 m diameter telescope with an infrared camera as well as from a computer simulation were performed. The results suggest that using the tilt-correction method yields an image quality that is much better than that obtained without the correction.

Algorithms↗

PubMed2004

Method of hologram multiplexing by use of a fiber bundle with rotary movement.

A simple method of rotating an optical fiber bundle is presented to apply the random-pattern referencing scheme to hologram multiplexing. In the theoretical study, a dependence of the diffraction efficiency on the number of spatial frequencies in the reference pattern is estimated with the Bragg diffraction theory. In the experiment, hologram multiplexing is performed in which 30 holograms are recorded in a LiNbO3 crystal and are read out by rotating a fiber bundle. The result shows that this simple approach enables us to perform the hologram multiplexing and also contributes to the building of a compact optical setup.

Journal Article↗

PubMed2003

Recovery of blurred images obtained through turbulent media.

Method for recovering blurred images taken through turbulent media, such as the atmosphere is presented. In this method amplitude and phase of the object's image are separately determined by special techniques of data processing, and finally the original image can be recovered. Principle and algorithm are described and the techniques to determine amplitude and phase are introduced by use of the results of computer simulations as well as light propagation experiments. As a demonstration to verify the utility of this method, images recovered by this method by use of data taken through a telescope of 1.5 m diameter, and the results of a computer simulation with atmospheric turbulence are shown. The results suggest that the presented method is well suited for the retrieval of blurred images.

Journal Article↗