• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.18-21
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• 2021

This paper analyzes the distortion correction of the in the micro DMD(digital micro mirror device) projector system using 0.25 or less optical throwing distance ratio. The distortion of projected image occurs depending on the performance of the optical lens, the installation location of the projection system, and the tilt of the screen. This study analyzed the physical tilt values influencing of the distortion of projected image, removed the tilt distortion of throwing distance ratio optical lens, and adjusted the distortion image by the simulation of calibration displacements. The results of this study demonstrated within 5% TV distortion reference. Moreover, the correction method reduced the pin-distortion correction of projection system.

• Journal of Digital Convergence
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• v.11 no.8
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• pp.331-340
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• 2013

Depaysement, suggested by the well-known surrealist Rene Magritte, has been used for and applied to many media. Application of depaysement through various media such as TV, commercial, and advertisement, attempted to provide interest by deviation from fixed ideas and visual shock, placing common objects in new and strange environment. The study applied screen projection mapping using a transparent screen and objet for different purposes to projection mapping media, applying depaysement to the artwork 'Illusion' in order to suggest visual pleasure, possibility as a new media, and projection mapping using transparent screen and objet. The work cases were suggested by applying expressive methods and effects according to three classifications - modulation of space, combination of conflicting images, and transformation and change of objects - in depaysement, and analyzed by types based on classification of the layout, typography, image, color, and time. Through 'Illusion,' new objet and characteristics of the media are applied and expanded by using projection mapping and depaysement.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.5
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• pp.43-51
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• 2009

In this paper, we propose an efficient method of face retrieval by using PCA(principal component analysis) based features. The coarse-to-fine strategy is adopted to sort the retrieval results in the lower dimensional eigenface space and to rearrange candidates at high ranks in higher dimensional eigenface space. To evaluate similarity between a query face image and class reference image, we utilize the PD (projection distance), MQDF(modified quadratic distance function) and MED(minimum Euclidean distance). The experimental results show that the proposed method which rearrange the retrieval results incrementally by using projection distance is efficient for face image retrieval.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.8
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• pp.1785-1791
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• 2003

This paper presents the mosaic method that the video sequence with shift and rotation information after Mellin Transform. The results are used to compute the projection matrix for each image registration. So before registration, we process camera calibration in order to reduce the image warp by camera and then compute the global projection matrix for image registration for reducing errors from rut image to last image. This paper describes the mosaic method that compute duplication and movement information quickly and robust noise using projection matrix on Mellin Transform.

• Journal of KIISE:Software and Applications
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• v.34 no.3
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• pp.266-274
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• 2007

This paper proposes a new reconstruction method of high-resolution facial image from a low-resolution facial image based on top-down machine learning and recursive error back-projection. A face is represented by a linear combination of prototypes of shape and that of texture. With the shape and texture information of each pixel in a given low-resolution facial image, we can estimate optimal coefficients for a linear combination of prototypes of shape and those that of texture by solving least square minimizations. Then high-resolution facial image can be obtained by using the optimal coefficients for linear combination of the high-resolution prototypes. In addition, a recursive error back-projection procedure is applied to improve the reconstruction accuracy of high-resolution facial image. The encouraging results of the proposed method show that our method can be used to improve the performance of the face recognition by applying our method to reconstruct high-resolution facial images from low-resolution images captured at a distance.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.3
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• pp.209-214
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• 2010

This paper proposes an algorithm of segmentation and title detection for document image. The automated title detection method that we have developed is composed of two phases, segmentation and title area detection. In the first phase, we extract and segment the document image. To perform this operation, the binary map is segmented by combination of morphological operation and CCA(connected component algorithm). The first phase provides segmented regions that would be detected as title area for the second stage. Candidate title areas are detected using geometric information, then we can extract the title region that is performed by removing non-title regions. After classification step that removes non-text regions, projection is performed to detect a title region. From the fact that usually the largest font is used for the title in the document, horizontal projection is performed within text areas. In this paper, we proposed a method of segmentation and title detection for various forms of document images using geometric features and projection profile analysis. The proposed system is expected to have various applications, such as document title recognition, multimedia data searching, real-time image processing and so on.

• Imaging Science in Dentistry
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• v.33 no.1
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• pp.43-49
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• 2003

Purpose : To evaluate the differences in bone height, bone width, and visibility of posterior spiral tomographic images according to various exposure directions, image layer thickness, and inclination of the mandibular inferior border. Materials and Methods: Six partially and completely edentulous dry mandibles were radiographed using Scanora spiral tomography. Spiral tomography was performed at different exposure directions (dentotangential and maxillotangential projection), image layer thicknesses (2 mm, 4 mm and 8 mm), and at various inclinations to the mandibular border (+ 100, 00 and -10°). The bone height and width was measured using selected tomographic images. The visibility of mandibular canal, crestal bone, and buccal and lingual surfaces were graded as 0, 1, or 2. Results : The bone width at the maxillo-tangential projection was wider than at the dento-tangential projection (p < 0.05). The visibility of buccal and lingual surface at the maxillo-tangential projection was higher than at the dento-tangential projection (p<0.05). Thinner image layer thicknesses resulted in greater visibility of buccal and lingual surfaces (p < 0.05). Bone height was greatest in the -10° group, and at the same time the bone width of the same group was the narrowest (p < 0.05). The visibility of alveolar crest and buccal surface of the + 10° group was the highest, while the visibility of the mandibular canal was greatest in the 00 group. Conclusion: When spiral tomography is performed at the mandibular posterior portion for visualization prior to implant surgery, it is important that the inferior border of mandible be positioned as parallel as possible to the floor. A greater improvement of visibility can be achieved by maintaining a thin image layer thickness when performing spiral tomography.

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.949-966
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• 1996

To establish the method for the most effective radiography and fluoroscopy, the abdominal organs of cats were investigeted using omnidirectional angles with the center of the body as the axis using an omnidirectional protective shielding X-ray system and a $360^{\circ}$ rotary restraint unit for use in small animals. The organs examined were the diaphragm, liver, stomach, colon, spleen and kidney. The results obtained in the present study were as follows: 1. Regardless of gas in the stomach present or not, it was feasible to distinguish the left and right crura in the lumbar portion of diaphragm in the oblique projection inclined over $30^{\circ}$ and under $90^{\circ}$ from the lateral projection. 2. Outlines of the exterior left lobe and the interior right lobe of the liver were observed in the oblique image inclined up to $60^{\circ}$ from the lateral image, while that of the exterior right lobe was noted in the oblique image inclined up to $60^{\circ}$ from the ventrodorsal-dorsoventral images. 3. It was necessary to have gas present in the stomach for detailed morphological observations of the stomach. It was most clearly observed in the right $30^{\circ}$ ventral-left dorsal oblique projection($120^{\circ}$ image) and the left $60^{\circ}$ dorsal-right ventral oblique projection($300^{\circ}$ image). 4. Morphology of the colon was observable in detail by the oblique projection inclined over $30^{\circ}$ from the lateral projection. 5. To observe the whole spleen it was required to have images from the ventrodorsal projection ($90^{\circ}$ image) to the right $60^{\circ}$ ventral-left dorsal oblique projection ($150^{\circ}$ image) as well as those from the dorsoventral projection ($270^{\circ}$ image) to the left-right lateral projection $0^{\circ}$ image). 6. Dorsal and ventral sides of the kidney were observable in the oblique images inclined $30^{\circ}$ from the lateral image. 7. Considering above findings collectively, it was thought that the results of present study might be useful for the analysis of abnormalies in each organ of cat.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.4
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• pp.145-151
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• 2011

The purpose of this study is to know some changes of resolution and image if we remove scattered ray using lead plate when doing lumbar lateral projection. Using 3 DR system(2 FD types, 1 CCD type) equipments and 2 film system equipments, we gain the image whether the phantom of abdomen equivalent sticking resolution chart has lead plate or not, whether we do collimation or not. Also, we use ion chamber, measure radiation exposure rate and change to entrance surface dose from it. we gain that images in the greatest condition of taking in clinic. 5 people in this group decoded resolution with our eyes, measured thickness of images and compared them from each equiments. Resolution has difference to size of collimation in DR FD type. Also there is no difference the original image with the new image which we abbreviated mAs. In DR CCD type, resolution didn't have difference whether lead plate is or not and whether we do collimation or not. In film type, existing or nonexisting of lead plate didn't influence on resolution. Lead plate makes the quality of image higher due to reducing scattered ray, it doesn't influence on resolution.

• Journal of information and communication convergence engineering
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• v.11 no.1
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• pp.62-68
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• 2013

This paper proposes a method for identification of harmful video images based on the degree of harmfulness in the video content. To extract harmful candidate frames from the video effectively, we used a video color extraction method applying a projection map. The procedure for identifying the harmful video has five steps, first, extract the I-frames from the video and map them onto projection map. Next, calculate the similarity and select the potentially harmful, then identify the harmful images by comparing the similarity measurement value. The method estimates similarity between the extracted frames and normative images using the critical value of the projection map. Based on our experimental test, we propose how the harmful candidate frames are extracted and compared with normative images. The various experimental data proved that the image identification method based on the 2-dimensional projection map is superior to using the color histogram technique in harmful image detection performance.