• Korean Journal of Optics and Photonics
• /
• v.19 no.6
• /
• pp.389-393
• /
• 2008

Enhanced reconstruction of heavy occluded objects was represented using estimation of variance in computational integral imaging. The system is analyzed to extract information of enhanced reconstruction from an elemental images set. To obtain elemental images with enhanced resolution, low focus error, and large depth of focus, synthetic aperture integral imaging (SAII) utilizing a digital camera has been adopted. The focused areas of the reconstructed image are varied with the distance of the reconstruction plane. When an occluded object is occluded heavily, an occluded object can not be reconstructed by removing the occluding object. To obtain reconstruction of the occluded object by remedying the effect of heavy occlusion, the statistical technique has been adopted.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.5
• /
• pp.1207-1212
• /
• 2015

In this paper, we propose three-dimensional (3D) visualization and recognition techniques of micro-objects under photon-starved conditions using photon counting integral imaging microscopy. To capture high resolution 2D images with different perspectives in the proposed method, we use Synthetic Aperture Integral Imaging (SAII). Poisson distribution which is mathematical model of photon counting imaging system is used to extract photons from the images. To estimate 3D images with 2D photon counting images, the statistical estimation is used. Therefore, 3D images can be obtained and visualized without any damage under photon-starved conditions. In addition, 3D object recognition can be implemented using nonlinear correlation filters. To prove the usefulness of our technique, we implemented the optical experiment.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.12
• /
• pp.49-55
• /
• 2013

A high-voltage highly-integrated analog front-end (AFE) IC for medical ultrasound imaging applications is implemented using standard 0.18-${\mu}m$ CMOS process. The proposed AFE IC is composed of a high-voltage (HV) pulser utilizing stacked transistors generating up to 15 Vp-p pulses at 2.6 MHz, a low-voltage low-noise transimpedance preamplifier, and a HV switch for isolation between the transmit and receive parts. The designed IC consumes less than $0.15mm^2$ of core area, making it feasible to be applied for multi-array medical ultrasound imaging systems, including portable handheld applications.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.7
• /
• pp.1598-1603
• /
• 2011

This paper describes an enhancement method for a computational pickup model. The conventional computational pickup model utilizes the ray-trace model and the pinhole model. The conventional model is very useful, however, it suffers from quality degradation of reconstructed images at long distances. To overcome the problem, we propose an accurate pickup model. The proposed model includes integration of the rays incoming to a sensor that generates a pixel, resulting in robustness on the Aliasing artifact. To show the effectiveness of the proposed method, experimental results are carried out. The results indicated that the proposed method is superior to the conventional method.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.5
• /
• pp.1171-1176
• /
• 2011

This paper describes an analysis on the relationship between elemental image size and object locations in the computational integral imaging reconstruction and in the pickup using a periodically-distributed lenslet array. A sparse sampling effect arises from a periodically-distributed lenslet array in the pickup of 3D objects. The relationship between elemental image size and object location is also reported. Based on the analysis, a method to eliminate the sparse sampling is proposed. To show the effectiveness of the proposed method, experimental results are carried out. It turns out that the theory works.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.9
• /
• pp.1711-1717
• /
• 2017

In this paper, we propose a fast and accurate method of extracting lens array lattice in integral imaging by using an appropriate calibration pattern image and fast median filtering. In order to extract the lattice of a lens array, vertical and horizontal edge images are required. To extract edge images, the well-known previous method used separable median filters. However, this method is slow and difficult to determine the median filter size. In order to overcome this problem, we try to improve speed by calculating median value through binary counting method. In addition, we propose a calibration pattern image that detects edges well and improves the accuracy. Experimental results indicate that the proposed method is superior to the existing method in extracting the lattice of a lens array in integral imaging.

• Korean Journal of Optics and Photonics
• /
• v.18 no.1
• /
• pp.24-30
• /
• 2007

We have studied depth conversion of a reconstructed image by means of recombination of the elemental images in the integral imaging system for 3D display. With the recombination, depth conversion to the pseudoscopic, the orthoscopic, the real or the virtual as well as to arbitrary depth without any distortion is possible under proper conditions. The conditions on the recombinations for the depth conversion are theoretically derived. The reconstructed images using the converted elemental images are presented.

• Korean Journal of Optics and Photonics
• /
• v.15 no.3
• /
• pp.234-240
• /
• 2004

In the integral imaging system for 3D display, we have investigated the image distortions, such as duplication and omission, which are presented in the reconstructed image. We have also discussed the quantitative condition which minimizes the distortion, with several fundamental variables. In addition, we present the experimental results which support the quantitative analysis of the distortion.

• Korean Journal of Optics and Photonics
• /
• v.16 no.3
• /
• pp.225-234
• /
• 2005

In the integral imaging system for 3D display, the elemental image size is closely related to the several variables, such as the size of elemental lens, the distance between elemental lens and elemental image, etc., on the pick up system. We have analyzed the geometric relation between the variables. In addition, we have investigated the integrated image variation for the individual and whole conversion of the size of the elemental images, different from in pick up process, and presented experimental results.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2005.11a
• /
• pp.21-24
• /
• 2005

본 논문에서는 3DTV를 위한 다시점 동영상 부호화 기법을 제안한다. 제안하는 다시점 동영상 부호화기는 다수의 카메라 입력에 대하여 기존의 MPEG 기반의 부호화 기법에서 사용된 시 ${\cdot}$ 공간적 중복성 제거와 각 시점에 해당하는 영상간의 공간적 중복성을 제거하여 부호화효율을 개선할 수 있다. 각 시점 영상간의 공간적 중복성을 효율적으로 제거하기 위하여 전역 시차보상(global disparity compensation)된 집적영상(Accumulated Image)를 사용하였다. 또한 기존의 디지털 TV 전송 표준인 MPEG-2를 기반으로 하였기 때문에 기존의 디지털 TV 표준을 크게 수정하지 않고 3DTV를 구현 할 수 있다. 제안하는 기법은 기존의 MPEG-2 기법으로 각 시점에 해당하는 영상을 각각 부호화한(simulcast 기법) 결과와 비교하여 객관적 화질면에서 우수하였으며, 각 시점간의 동기화 문제도 해결 할 수 있었다.