• The Journal of Society for e-Business Studies
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• v.17 no.3
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• pp.1-14
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• 2012

As the techniques of electronic and information are advancing, the computing power of a smart phone is becoming more powerful and the storage capacity of a smart phone is becoming larger. As the result, various new useful services are becoming available on smart phones. The context-aware service and mobile augmented reality have recently been the most popular research topics. For those newly developed services, identifying the object in the picture taken by the camera on the phone performs an extremely important role. So, many researches of identifying pictures have been published and most of them are based on the time consuming image recognition techniques. On the contrary, this paper introduces a very fast and effective method of identifying the objects on the photo making use of the sensor data obtained from the smart phone and electronic maps. Our method estimates the line of sight of the camera with the location and orientation information provided by the smart phone. Then it finds any element of the map which intersects the line of sight. By investigating those intersecting elements, our method identifies the objects on the photo.

• Journal of the Korea Society of Computer and Information
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• v.19 no.7
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• pp.17-25
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• 2014

In the devices that leave video records, it is an important issue to distinguish whether the input image is a real object or a photo when securing an identifying image. Using a single image and sensor, which is a simple way to distinguish the target from distance measurement has many weaknesses. Thus, this paper proposes a way to distinguish a simple photo and a real object by using stereo images. It is not only measures the distance to the target, but also checks a three-dimensional effect by making the depth map of the face area. They take pictures of the photos and the real faces, and the measured value of the depth map is applied to the learning algorithm. Exactly through iterative learning to distinguish between the real faces and the photos looked for patterns. The usefulness of the proposed algorithm was verified experimentally.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.1
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• pp.95-103
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• 1999

Low pressure combustion characteristics of the composite solid propellants were studied in terms of the propellant burning rate, ignition processes, and the structure of the extinguished surfaces. Optical Vacuum Strand Burner(OVSB) system was designed and configured for this purpose. Burning rates of the propellants were measured at subatmospheric pressure by developed test method in OVSB. The ignition and combustion phenomena of the studied propellants in the combustion chamber of OVSB were recorded and analyzed with the camera and VCR(30 frames/s). Burning surfaces of the propellants were extinguished by rapid depressurization method and analyzed with Scanning Electron Microscope(SEM).

• Journal of Digital Convergence
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• v.11 no.6
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• pp.269-273
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• 2013

Exposure dose to the examinee was measured using glass dosimeter in the test using panorama device at the time of dental treatment. As a result of measuring expose dose to lens according to the different sizes of Pb banding of own manufacturing to reduce exposure dose to lens especially sensitive to radiation, it was verified that exposure dose to lens varied depending on the size of the Pb banding. With the size of Pb banding of $3{\times}20{\times}0.2cm$, exposure dose tended to increase higher than normal value, and with the size of or more than $5{\times}20{\times}0.2cm$, it decreased. And also, the obtained image with the size of $7{\times}20{\times}0.2cm$ was not suitable for diagnosis. Therefore, it is expected that exposure dose would be reduced by using Pb banding of the size of not less than $5{\times}20{\times}0.2cm$ and not more than $6{\times}20{\times}0.2cm$ in the test, to minimize exposure dose and conduct panorama test efficiently.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.114-123
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• 2014

Vehicle Black Box (Event Data Recorder EDR) only recognizes the general surrounding environments of load. In addition, general EDR is difficult to recognize the images of a sudden illumination change. It appears that the lens is being a severe distortion. Therefore, general EDR does not provide the clues of the circumstances of the accident. To solve this problem, we estimate the value of Normalized Luminance Descriptor(NLD) and Normalized Contrast Descriptor(NCD). Illumination change is corrected using Normalized Image Quality(NIQ). Second, we are corrected lens distortion using model of Field Of View(FOV) based on designed method of fisheye lens. As a result, we propose integration algorithm of two methods that correct distortions of images using each Gamma Correction and Lens Correction in parallel.

• Journal of the Korean Society of Radiology
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• v.1 no.2
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• pp.23-30
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• 2007

This paper presents a method of generating 3-dimensional images by preprocessing 2-dimensional abdominal images obtained using CT (computed tomography) and MRI (magnetic resonance imaging) through segmentation, threshold technique, etc. and apply the method to virtual endoscopy. Three-dimensional images were visualized using indirect volume rendering, which can render at high speed using a general-purpose graphic accelerator used in personal computers. The algorithm used in the rendering is Marching Cubes, which has only a small volume of calculation. In addition, we suggested a method of producing 3-dimensional images in VRML (virtual reality modeling language) running on the Web browser without a workstation or an exclusive program. The number of nodes, the number of triangles and the size of a 3-dimensional image file from CT were 85,367, 174,150 and 10,124, respectively, and those from MRI were 34,029, 67,824 and 3,804, respectively.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.2
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• pp.24-31
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• 2011

This paper proposes spatio-temporal denoising algorithm based on nonlocal means. Though the conventional denoising algorithms based on nonlocal means have good performance in noise removal, it is difficult to implement them into the hardware system due to much computational load and the need for several frame buffers. Therefore we adopted infinite impulse response temporal noise reduction algorithm in the proposed algorithm. Proposed algorithm shows less artificial denoised result in the motionless region. In the motion region, spatial filter based on efficiently improved nonlocal means algorithm conduct noise removal with less motion blur. Experimental results including comparisons with conventional algorithms for various noise levels and test images show the proposed algorithm has a good performance in both visual and quantitative criteria.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.569-578
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• 2009

In this paper, we describe the color reproduction system for color images captured by digital camera. The system uses a color compensation chart to estimate the transformation between the colors in the image and the reference colors in the chart. The color reproduction process consists of two steps, i.e., the profile creation process and the profile application process. During the pro-file creation process, the relationships between the captured colors and the ref-erence colors are estimated. And the system creates a color profile and embeds the estimation result in the profile. During the profile application process, the colors in the images which are captured under the same condition as that of the chart image are reproduced using the created color profile. To evaluate the per-formance of the system, we perform experiments under various conditions. And we compare the results with those of widely used commercial applications.

• Korean Journal of Digital Imaging in Medicine
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• v.9 no.2
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• pp.23-30
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• 2007

This study attempts to propose an appropriate method of using digital medical imaging equipments, by studying the effects of automatic exposure control(AEC), grid ratio and the change of radiography distance on the patient dose and detertor acquisition dose during the procedure of acquiring image through a digital medical imaging detector. The change of dose following the change of grid ratio's exposure and radiography distance was measured, by using an abdominal phantom organized with tissue equivalent materials in an amorphous silicon thin film transistor detecter installed with AWC. The case to use grid ratio 12 : 1, focal distance 180cm to radiography distance 110cm in AEC, the patient dose increased rather when we used grid ration 10 : 1, focal distance 110cm. When AEC was not used,the dose necessary for image acquisition decreased as the grid ratio became higher and the distance became further. but detector acquisition dose was not reduced when in applied AEC. When purchasing digiral medical imaging equipments, optional items such as AEC and grid shall be accurately selected to satisfy the use of the equipments. Radiography error made by radiation technologist and unnenessary patient dose can be reduced by selecting equipments with a radiography distance marker equipment when it did not apply AEC. These equipments can also be helpful in maintaining high imaging quality, one of the merits of digital detectors.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.597-602
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• 2020

The study was conducted to improve the efficiency of the test and to reduce the exposure dose of patients and operators by analyzing the difference in the moving speed of Lipiodol according to the temperature during lymphography. The device for injecting Lipiodol at a constant pressure was self-made, and after inserting Lipiodol into the Connecting Tube, the moving speed of the contrast agent was photographed at temperatures of 26℃, 36℃, and 46℃ using a heat transfer device. Lipiodol movement time from the Support Catheter to 20cm was measured and analyzed, and statistical significance was confirmed. In the 46℃ environment, the average moving time was 11 seconds, at 36℃ the average was 13 seconds, and at 26℃ the average was 17 seconds. Lipiodol showed a significant difference in moving time with increasing temperature (p<.001), and it was confirmed that the higher the temperature, the faster the moving speed. In the case of lymphangiography, when heated to a certain temperature (46 degrees) rather than injecting Lipiodol at room temperature, the injection speed can be increased and the speed of movement in the lymphatic vessel can be improved.