• Progress in Medical Physics
• /
• v.24 no.4
• /
• pp.205-212
• /
• 2013

Recent developments of image guided radiation therapy (IGRT), especially the On Board Imaging (OBI) system and the cone beam CT (CBCT), enable the radiation treatment more accurate and reliable. IGRT is widely used in the radiation therapy as a standard of care. Use of IGRT is even expected to increase in the near future. IGRT is only beneficial to patients when it is used with proper considerations of safety and appropriateness of the techniques. Institutional procedure should be developed based on the clinical need and the deep understanding of the system before applying the new technique to the clinic. Comprehensive QA program should be established before to the clinic and imaging dose should be considered when preparing the departmental practice guidelines for IGRT.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.468-470
• /
• 2002

We have designed X-ray detection system and multi-channel data acquisition system for Spiral CT application. X-ray detection system consists of scintillator and photodiode. Scintillator converts X-ray into visible light. Photodiode converts visible light into electrical signal. The multi-channel data acquisition system consists of analog, digital, master and backplane board. Analog board detects electrical signal and amplifies signal by 140dB. Digital board consists of MUX(Multiplex) which routes multi-channel analog signal to preamplifier, and ADC(Analog to Digital Converter) which converts analog signal into digital signal. Master board supplies the synchronized clock and transmits the digital data to image reconstructor. Backplane provides electrical power, analog output and clock signal. The system converts the projected X-ray signal over the detector array with large gain, samples the data in each channel sequentially, and the sampled data are transmitted to host computer in a given time frame. To meet the timing limitation, this system is very flexible since it is implemented by FPGA(Field Programmable Gate Array). This system must have a high-speed operation with low noise and high SNR(signal to noise ratio), wide dynamic range to get a high resolution image.

• Archives of design research
• /
• v.13 no.1
• /
• pp.247-256
• /
• 2000

Recently, foreign tourists and car owners or motorists are increasing, so tourist sign boards are necessary to inform them. Unfortunately, tourist sign boards are difficult to understand because they are often written incorrectly. This paper has a thorough grasp of this problem and will present an ideal standard model which is precise and detailed. This paper includes research of tourist boards sign Seoul, Kyongju, Pusan, Kwangju, Yosu, Kwang reung in Korea. Also tourist sign boards in the U.K, France, Switzerland, Italy and Austria will be discussed. A survey was conducted of eight hundred people to determine tourist information is obtained. In conclusion, tourist sign board should convey accurate and useful information to people of all ages. Tourist information should be systematic and logical. An ideal standard model of tourist signs will render traveling easier for tourists all over the world. It will be more convenient for both kinds of tourist; domestic and foreign. Futhermore good tourist sign board will give an excellent and bright image.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.2005-2006
• /
• 2011

Due to the advantages of small sizes, more I/O ports, etc., Ball Grid Array (BGA) has been used in the production of printed circuit board (PCB). However, BGA voids can degrade the performance of the board and cause failure. To automatically detect the voids in X-ray image, a novel blob filter that makes use of the local image gradient magnitude is proposed in this paper. The utilization of the local image gradient magnitude makes the proposed filter invariant to the image brightness, void shape, void position, and component interference. Furthermore, different sizes of box filters are employed to analyze the image in multi-scale, and as a result, the proposed blob filter is robust to void size. Experimental results show that the proposed method can obtain void detection accuracy up to 96.104% while keep low false ratio.

• Journal of Broadcast Engineering
• /
• v.23 no.5
• /
• pp.606-613
• /
• 2018

This study is concerned with implementing an external memory expansion device for large-scale image processing. It consists of an external memory adapter card with a PCI(Peripheral Component Interconnect) Express Gen3 x8 interface mounted on a graphics workstation for image processing and an external memory board with external DDR(Dual Data Rate) memory. The connection between the memory adapter card and the external memory board is made through the optical interface. In order to access the external memory, both Programmable I/O and DMA(Direct Memory Access) methods can be used to efficiently transmit and receive image data. We implemented the result of this study using the boards equipped with Altera Stratix V FPGA(Field Programmable Gate Array) and 40G optical transceiver and the test result shows 1.6GB/s bandwidth performance.. It can handle one channel of 4K UHD(Ultra High Density) image. We will continue our study in the future for showing bandwidth of 3GB/s or more.

• Journal of the Institute of Convergence Signal Processing
• /
• v.11 no.3
• /
• pp.189-196
• /
• 2010

In this paper, we proposed the adaptive local sigma filter reducing noises generated by an image sensor. The small noises generated by the image sensor are amplified by increased an analog gain and an exposure time of the image sensor together with information. And the goal of this work was the system design that is reduce the these amplified noises. Edge data are extracted by Flatness Index Map algorithm. We made the threshold adaptively changeable by the luminance average in this algorithm that extracts the edge data not in high luminance, but just low luminance. The Local Sigma Filter performed only about the edge pixel that were extracted by Flatness Index Map algorithm. To verify the performance of the designed filter, we made the Window test program. The hardware was designed with HDL language. We verified the hardware performance of Local Sigma Filter system using FPGA Demonstration board and HD image sensor, $1280{\times}720$ image size and 30 frames per second.

• Korean Journal of Remote Sensing
• /
• v.15 no.3
• /
• pp.209-216
• /
• 1999

KITSAT-3, the third satellite of KITSAT series which has been developed for the last four and half years with purely Korean design and implementation technology, was launched successfully at last. All subsystems were tested and validated during the initial operation of the satellite. During the initaial operation phase, the Earth imaging camera on board KITSAT-3 acquisited several tens of scenes all over the world and transmitted the image data to ground station. The quality of images and the reliability of data transmission-reception system were tested qualititively and quantititively, respectively. In this paper, we summarize the camera, data handling, on-board memory, and image data transmission system of KITSAT-3 as well as the image receiving and archiving system in ground station. The error rate of image data transmission and reception was tested during the initial operation phase. The average data transmission error rate satisfied the initial requirement of less than 1%. The error rate will be reduced through the continuous work of test and stabilization of the ground system hardware.

• Journal of Biosystems Engineering
• /
• v.26 no.3
• /
• pp.279-286
• /
• 2001

The purpose of this study were to organize a sorting system, to develop an algorithm of image processing for the shape sorting, and to finally develop a scientific and objective shape sorting system of Korean Red-Ginseng for mechanization of the shape sorting. The results of this study are followed. 1. The shape sorting system of Korean Red-Ginseng consists of a control computer, a color CCD camera(WV-CP4110) for image processing, an image processing board(DT3153), and an image acquisition unit. 2. Many image processing skill, such as sliding, stretching, threshold, binary and D$\sub$t/ were used to analyze the shape sorting factors of Korean Red-ginseng. 3. The sorting accuracy of the shape sorting system for the Korean Red-Ginseng was 74.7%. It is 21.1% lower than that of human inspector. Although the system has low accuracy, using more cameras may improve its sorting accuracy.

• Journal of Information Processing Systems
• /
• v.2 no.3 s.4
• /
• pp.153-158
• /
• 2006

In this paper, we propose an image interpolator for low computational complexity. The proposed image interpolator supports the image scaling using a modified cubic convolution interpolation between the input and output resolutions for a full screen display. In order to reduce the computational complexity, we use the difference in value of the adjacent pixels for selecting interpolation methods and linear function of the cubic convolution. The proposed image interpolator is compared with the conventional one for the computational complexity and image quality. The proposed image interpolator has been designed and verified by Verilog HDL(Hardware Description Language). It has been synthesized using the Xilinx VirtexE FPGA, and implemented using an FPGA-based prototype board.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.11a
• /
• pp.503-507
• /
• 2004

This paper is concerned with the measurement of low-frequency vibrations of structures using the image processing method. To measure the vibrations visually, the measurement system consists of a camera, an image grabber board, and a computer. The specific target installed on the structure is used to calculate the vibration of structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the size of image. In this paper, we discuss the methodology for the vibration measurement using the image processing method. The method enables us to measure the displacement directly without any contact. The resolution of the vibration measurement can be refined but limited to the sub centimeter displacement.