Eriko Watanabe

High-precision microscopic phase imaging without phase unwrapping for cancer cell identification

A high-dynamic-range two-dimensional phase measurement system that does not need phase unwrapping processing was developed. The optical path difference distribution about three wavelengths could be measured, demonstrating the high dynamic-range of this system. We also experimentally investigate the potential of this approach for biological applications that are cancer identification and assessing the limitations of the passage culture of biological cells.

High-speed holographic correlation system by a time-division recording method for copyright content management on the internet

Using a holographic disc memory on which a huge amount of data can be stored, we constructed an ultra-high-speed, all-optical correlation system. In this method, multiplex recording is, however, restricted to “one page” on “one spot.” In addition, signal information must be normalized as data of the same size, even if the object data size is smaller. Therefore, this system is difficult to apply to part of the object data scene (i.e., partial scene searching and template matching), while maintaining high accessibility and programmability. In this paper, we develop a holographic correlation system by a time division recording method that increases the number of multiplex recordings on the same spot. Assuming that a four-channel detector is utilized, 15 parallel correlations are achieved by a time-division recording method. Preliminary correlation experiments with the holographic optical disc setup are carried out by high correlation peaks at a rotational speed of 300 rpm. We also describe the combination of an optical correlation system for copyright content management that searches the Internet and detects illegal contents on video sharing websites.

Optical correlation-based cross-domain image retrieval system

A novel cross-domain image retrieval system that is based on a high-speed optical correlator with a coaxial holographic system is presented. Our newly designed conversion module for the optical correlator allows various kinds of data to be converted to pagedata with a uniform optical intensity by using an autoencoder, which is difficult with other conventional methods. By using our conversion module, an existing model for deep learning could be utilized as a feature extractor. A sketch-based cross-domain image retrieval system with the goal of discovering similar photos by querying freehand human sketches was experimentally demonstrated using our optical correlator. We believe that this proposed optical correlation-based system helps expand the applications of the optical correlator.

High-speed holographic correlation system for video identification on the internet

Automatic video identification is important for indexing, search purposes, and removing illegal material on the Internet. By combining a high-speed correlation engine and web-scanning technology, we developed the Fast Recognition Correlation system (FReCs), a video identification system for the Internet. FReCs is an application thatsearches through a number of websites with user-generated content (UGC) and detects video content that violates copyright law. In this paper, we describe the FReCs configuration and an approach to investigating UGC websites using FReCs. The paper also illustrates the combination of FReCs with an optical correlation system, which is capable of easily replacing a digital authorization sever in FReCs with optical correlation.

High Speed Holographic Optical Correlator for Face Recognition

Owing to the Japanese government plan, U-Japan, which promised to bring about the socalled ‘ubiquitous society’ by 2010, the use of Internet has dramatically increased and accordingly, development of the system through IT networks is thriving. The term ‘ubiquitous society’ became a buzzword, signifying easy access to content on the internet for anybody, anywhere and at any time. Face recognition has become the key technique, as a ‘face’ carries valuable information, captured for security purposes, without physical contact. They can function as identity information for purposes such as login for bank accounts, access to buildings, anti-theft or crime detection systems using CCTV cameras. Furthermore, within the domain of entertainment, face recognition techniques are applied to search for celebrities who look alike. Against this backdrop, a high performance face recognition system is sought after. Face recognition has been used in a wide range of security systems, such as monitoring credit card users, identifying individuals with surveillance cameras and monitoring passengers at immigration control. Face recognition has been studied since the 1970s, with extensive research into and development of digital processing (Kaneko & Hasegawa, 1999; Kanade, 1971 ; Sirovich & Kirby, 1991 ; Savvides, M. et al. 2004). Yet there are still many technical challenges to overcome; for instance, the number of images that can be stored is limited in currently available systems, and the recognition rate needs to be improved to take account of photographic images taken at different angles and in varying conditions. In contrast to digital recognition, optical analog operations process two-dimensional images instantaneously and in parallel, using a lens-based Fourier transform function. In the 1960s, two main types of correlator came into existence; the Vanderlugt Correlator and the Joint Transform Correlator (JTC) (Goodman & Moeller, 2004). Some correlators were a combination of the two (Thapliya & Kamiya, 2000; Kodate Inaba Watanabe & Kamiya, 2002 ; Kobayashi & Toyoda, 1999 ; Carrott Mallaley Dydyk & Mills, 1998). The authors previously proposed and produced the FARCO (Fast Face Recognition Optical Correlator), which was based on the Vanderlugt Correlator((a) Watanabe & Kodate 2005; (b)Watanabe & Kodate, 2005). Combined with high-speed display devices, four-channel processing was able to achieve operational speeds of up to 4000 faces/s. Running trial experiments on a 1-to-N identification basis using the optical parallel correlator, we succeeded in acquiring low error rates of 1 % False Acceptance Rate (FAR) and 2.3 % False Rejection Rate (FRR)( Savvides et O pe n A cc es s D at ab as e w w w .in te ch w eb .o rg

Bio-imaging using planar lightwave circuit digital holographic microscope

We have proposed a digital holographic microscope using a planar lightwave circuit. Using the system, we report the evaluation of the spatial resolution and measurement of Closterium.

Optical–digital hybrid image search system in cloud environment

To improve the versatility and usability of optical correlators, we developed an optical–digital hybrid image search system consisting of digital servers and an optical correlator that can be used to perform image searches in the cloud environment via a web browser. This hybrid system employs a simple method to obtain correlation signals and has a distributed network design. The correlation signals are acquired by using an encoder timing signal generated by a rotating disk, and the distributed network design facilitates the replacement and combination of the digital correlation server and the optical correlator.

Automated Disease Identification using computational 3D Optical Sensing and Imaging Systems

In this invited paper, we present an overview of our reported work on 3D sensing and imaging applied to automated cell identification. The sensing and imaging methods include digital holographic imaging, interferometric systems, and integral imaging. We show that 3D sensing and imaging approaches combined with appropriate pattern recognition algorithms provide an impressive approach for automated cell identification with compact field portable systems.

High-resolution and wide-field phase imaging through lensless digital holographic microscopy

This paper presents the development of phase-shifting lensless digital holographic microscopy that has high resolution (0.98 µm) and supports wide-field imaging (2 mm × 2 mm) with localized autofocusing.

Improvement of the correlation speed in an optical correlation system using a holographic disc

We developed an optical correlation system that has a potential to achieve data transfer speed higher than 110 Gbps. An equal error rate of 0% with a 2-µm recording pitch and a disc rotation speed of 900 rpm were obtained.