• Journal of information and communication convergence engineering
• /
• 제16권3호
• /
• pp.153-159
• /
• 2018

In this paper, we present a three-dimensional (3D) optical encryption technique for quick response (QR) code using computational synthesized integral imaging, computational volumetric reconstruction, and double random phase encryption. Two-dimensional (2D) QR code has many advantages, such as enormous storage capacity and high reading speed. However, it does not protect primary information. Therefore, we present 3D optical encryption of QR code using double random phase encryption (DRPE) and an integral imaging technique for security enhancement. We divide 2D QR code into four parts with different depths. Then, 2D elemental images for each part of 2D QR code are generated by computer synthesized integral imaging. Generated 2D elemental images are encrypted using DRPE, and our method increases the level of security. To validate our method, we report simulations of 3D optical encryption of QR code. In addition, we calculated the peak side-lobe ratio (PSR) for performance evaluation.

• 한국정보통신학회논문지
• /
• 제20권12호
• /
• pp.2363-2369
• /
• 2016

본 논문에서는 집적 영상과 컴퓨터 재생 기술을 활용한 3차원 QR 코드 생성 기술을 제안한다. 제안하는 기술에서는 2차원 QR 코드를 네 개의 면으로 나누어 각각의 면을 서로 다른 깊이에 배치한 뒤 깊이가 추가된 3차원 QR 코드를 합성조리개 집적 영상과 컴퓨터 재생 기술을 사용하여 생성한다. 이 과정에서 3차원 영상 기술 중 하나인 집적 영상 기술을 사용한다. 마지막으로, 3차원 QR 코드를 집적영상을 이용하여 컴퓨터 재생을 한 뒤 각 면을 배치했던 깊이 부분에서 영상을 재생하고 조합하면 3차원 QR 코드를 읽을 수 있다. 따라서 QR 코드를 읽을 때 보안을 강화할 수 있다. 본 논문에서는 제안된 기술이 QR 코드를 읽을 때 보안을 강화할 수 있음을 보이기 위하여 광학적 실험과 컴퓨터 재생을 수행하였다. 또한, 재생 깊이를 알고 있을 때, 3차원 QR 코드를 읽을 수 있음을 보였다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제46권5호
• /
• pp.427-433
• /
• 2023

This study aimed to quantitatively compare the diameters measured directly from the coronal plane or sagittal plane of 2D digital subtraction angiography (DSA) and the cross-sectional area-converted diameters calculated from contrast-enhanced MR (CE-MR) imaging. A retrospective analysis was conducted on 20 patients who underwent both 2D DSA and CE-MR imaging. Firstly, the venous diameters of the superior sagittal sinus (SSS) and transverse sinus (TS) were directly measured from 2D DSA. Subsequently, the axial planes for SSS diameter and the sagittal plane for TS in CE-MR imaging were utilized to calculate cross-sectional area-based converted diameters. The numerical values obtained from 2D DSA and CE-MR imaging were compared pairwise at each location. For SSS, the diameter measured by 2D DSA was 27% larger than the conversion-based diameter from CE-MR imaging (9.8±1.4 mm vs. 7.1±1.3 mm, P<0.05). Similarly, for the right TS, the difference was 16% (8.8±3.2 mm vs. 7.4±2.0 mm, P<0.05), and for the left TS, the difference was 22% (8.4±2.8 mm vs. 6.6±1.3 mm, P<0.05). In conclusion, the diameter measured directly in conventional 2D DSA may be larger than the diameter converted based on the cross-sectional area. Therefore, when selecting the size of the stent, it is crucial to make precise determinations while keeping this fact in mind.

• 한국안전학회지
• /
• 제18권4호
• /
• pp.98-104
• /
• 2003

Various nondestructive evaluation (NDE) techniques have been studied to locate steel rebars of dowel, and to detect invisible damage such as voids and cracks inside concrete and debonding between rebars and concrete caused by corrosions and earthquakes. In this study, the aurhors developed 3-dimensional (3D) electromagnetic (EM) imaging technology to detect such damage and to identify exact location of steel rebars of dowel. The authors have developed sub-surface two-dimensional (2D) imaging technique using tomographic antenna array in previous works. In this study, extending the earlier analytical and experimental works on 2D image reconstruction, a 3D microwave imaging system using tomographic antenna array was developed, and multi-frequency technique was applied to improve quality of the reconstructed image and to reduce background noises. This paper presents the analytical expressions of numerical focusing procedures for 3D image reconstruction and numerical simulation to study the resolution of the system and the effectiveness of multi-frequency technique. Also, the design of 4?4 antenna array with switching devices is introduced as a preliminary study for the final design of whole array.

• 복식문화연구
• /
• 제19권2호
• /
• pp.316-323
• /
• 2011

This research aim concerns questioning how we can generate environments suggestive of nature fused with built environments through textiles. Through literature reviews and experiments with available the 3D imaging techniques of Holography, Lenticular and other new technologies. We also have researched towards finding the most effective method for 3D imaging techniques for textile applications. The advantage of the combining technique is to create the possibility of seeing a number of different floating 3D illusory images, depending on the viewing angle. This objective is to produce intriguing textile patterns and images in which the objects and colours change as viewpoints change. Experimental work was carried out in collaboration with professional textile researchers, scientists, artists and designers conducting research in this field.

• 대한의용생체공학회:의공학회지
• /
• 제31권3호
• /
• pp.177-186
• /
• 2010

In 3D ultrasound color Doppler imaging (CDI), 8-16 pulse transmissions (ensembles) per each scanline are used for effective clutter rejection and flow estimation, but it yields a low volume acquisition rate. In this paper, we have evaluated three flow estimation methods: autoregression (AR), eigendecomposition (ED), and autocorrelation combined with adaptive clutter rejection (AC-ACR) for a small ensemble size (E=4). The performance of AR, ED and AC-ACR methods was compared using 2D and 3D in vivo data acquired under different clutter conditions (common carotid artery, kidney and liver). To evaluate the effectiveness of three methods, receiver operating characteristic (ROC) curves were generated. For 2D kidney in vivo data, the AC-ACR method outperforms the AR and ED methods in terms of the area under the ROC curve (AUC) (0.852 vs. 0.793 and 0.813, respectively). Similarly, the AC-ACR method shows higher AUC values for 2D liver in vivo data compared to the AR and ED methods (0.855 vs. 0.807 and 0.823, respectively). For the common carotid artery data, the AR provides higher AUC values, but it suffers from biased estimates. For 3D in vivo data acquired from a kidney transplant patient, the AC-ACR with E=4 provides an AUC value of 0.799. These in vivo experiment results indicate that the AC-ACR method can provide more robust flow estimates compared to the AR and ED methods with a small ensemble size.

• 한국정보통신학회논문지
• /
• 제18권11호
• /
• pp.2799-2804
• /
• 2014

본 논문에서는 집적 영상 기술을 사용하여 3차원 정보를 추출하는 지도 시스템을 제안한다. 집적 영상 기술은 렌즈 배열을 가지는 2차원 영상 획득장치를 사용하여 다수의 서로 다른 원근감을 가지는 요소 영상을 기록하고 이를 이용하여 3차원 정보를 획득하고 디스플레이하는 기술이다. 본 논문에서는 각 요소 영상간의 위치 차이를 절대 차이의 합 (Summation of Absolute Difference: SAD)를 사용하여 구하고 이를 이용하여 3차원 정보를 추출한다. 따라서, 3차원 물체의 높이 정보를 구할 수 있다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.1318-1321
• /
• 2006

We describe the 3D/2D convertible color display based on modified integral imaging. In the proposed method a color liquid crystal display panel is used as a transmission-type display panel and enables a color 3D/2D convertible display system. The principle of the proposed method will be explained and methods to overcome the color dispersion problem will be discussed also.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.1127-1130
• /
• 2008

Integral imaging is a three-dimensional display technique which has 100 years of history. The method is characterized by offering full parallax, almost-continuous viewpoints and easiness of moving picture display. In this paper, the history of the method is briefly explained and overview of its current status is provided.

• 한국방사선학회논문지
• /
• 제16권7호
• /
• pp.969-974
• /
• 2022

디지털 엑스레이 디텍터 영상 취득에 있어 동적 범위를 최대화하고 영상지연을 최소화하기 위해서는 엑스레이 영상센서의 픽셀내 포토다이오드에 존재하는 잔류 정전기생용량을 빠르고 완전하기 제거하는 것이 매우 중요하다. 이러한 요구사항은 특히 고속 프레임과 낮은 영상지연이 필요한 산업용 2D/3D 자동화 엑스레이 검사와 의료용 CT 엑스레이 디텍터에 특별히 요구된다. 본 연구는 리셋 박막트랜지스터, 리드아웃 박막트랜지스터 그리고 포토다이오드로 픽셀이 구성된 듀오픽스^TM 엑스레이 영상센서를 처음으로 제안한다. 듀오픽스^TM 엑스레이 영상센서의 구동을 검증하기 위해 105 ㎛의 픽셀 사이즈, 347 mm × 430 mm의 영상영역 그리고 3300 × 4096의 픽셀 (13.5M pixels)을 갖는 듀오픽스^TM 엑스레이 영상센서를 설계, 제작하여 모듈테스터와 영상취득 프로그램을 통해 영상을 취득하였다.