In recent years, tele-communication using video calling functions of, e.g., PCs and smartphones has been used in various situations, such as conversations in personal life and online meetings at work. Aiming at the enhancement of the sense of presence in video telecommunication systems, a holographic off-axis mirror, which is a see-through off-axis reflector fabricated as a holographic optical element (HOE), is utilized as an upright screen for a virtual- image display and a face image capture with eye-contact. Since the chromatic dispersion of the HOE causes image blur, we previously proposed a optical dispersion compensation technique for this system. In this paper, we extend the dispersion-compensation technique to full-color virtual-imaging systems with a holographic off-axis mirror exposed by red, green, and blue lasers. We demonstrate the proof of concept system experimentally using an A4-sized full-color holographic off-axis mirror. We also apply the same concept to the off-axis image capturing system using a full-color holographic mirror, which is also experimentally demonstrated. The proposed full-color virtual-image display and camera system will enable more attractive visual telecommunication systems, such as video phone or online conference.
Human epidermal growth factor receptor 2 (HER2), a transmembrane tyrosine kinase receptor encoded by the ERBB2 gene on chromosome 17q12, is a predictive and prognostic biomarker in invasive breast cancer (BC). Approximately 20% of BC are HER2-positive as a result of ERBB2 gene amplification and overexpression of the HER2 protein. Quantification of HER2 is performed routinely on all invasive BCs, to assist in clinical decision making for prognosis and treatment for HER2-positive BC patients by manually counting gene signals. We propose an automated system to quantify the HER2 gene status from chromogenic in situ hybridization (CISH) whole slide images (WSI) in invasive BC. The proposed method selects untruncated and nonoverlapped singular nuclei from the cancer regions using color unmixing and machine learning techniques. Then, HER2 and chromosome enumeration probe 17 (CEP17) signals are detected based on the RGB intensity and counted per nucleus. Finally, the HER2-to-CEP17 signal ratio is calculated to determine the HER2 amplification status following the ASCO/CAP 2018 guidelines. The proposed method reduced the labor and time for the quantification. In the experiment, the correlation coefficient between the proposed automatic CISH quantification method and pathologist manual enumeration was 0.98. The p-values larger than 0.05 from the one-sided paired t-test ensured that the proposed method yields statistically indifferent results to the reference method. The method was established on WSI scanned by two different scanners. Through the experiments, the capability of the proposed system has been demonstrated.
Whole slide imaging (WSI) scanner scans pathological specimens to produce digital slides to use in pathology practice, research and computational pathology which enables monitor-based diagnosis and image analysis. However, the scanned image is sometimes insufficient in quality such as focusing-error and noise. Therefore, a quality evaluation method is obligatory for practical use of WSI system. In previous work, referenceless quality evaluation technique was proposed for this purpose but some artefacts (i.e. tissue-fold, air-bubble) in slide would also be detected as false positives, while they are useless. In this paper, we proposed a method for the practical system to assess WSI quality with eliminating false detection due to the artefacts. Firstly, support vector machine (SVM) was utilized for detecting ROIs with artefacts and then the image quality was evaluated excluding detected ROIs. Through the experiments, the effectiveness of proposed system has been demonstrated.
Volume hologram, which has unique characteristics such as wavelength and angular selectivity, is a powerful tool for enabling computational imaging. For example, light-field three-dimensional imaging can be realized with a thin, flat, and transparent material by utilizing the volume hologram. This report mainly introduces the light-field imaging system utilizing volume hologram with describing a calibration method and an experimental result. The talk corresponding to this report also addresses other imaging applications of the volume hologram.
We propose a fast calculation method to synthesize a computer-generated hologram (CGH) of realistic deep three-dimensional
(3D) scene. In our previous study, we have proposed a calculation method of CGH for reproducing such scene
called ray-sampling-plane (RSP) method, in which light-ray information of a scene is converted to wavefront, and the
wavefront is numerically propagated based on diffraction theory. In this paper, we introduce orthographic projection to the
RSP method for accelerating calculation time. By numerical experiments, we verified the accelerated calculation with the
ratio of 28-times compared to the conventional RSP method. The calculated CGH was fabricated by the printing system
using laser lithography and demonstrated deep 3D image reconstruction in 52mm×52mm with realistic appearance effect
such as gloss and translucent effect.