• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.1
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• pp.33-42
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• 2005

Identifying color codes needs precise color information of their constituents, and is far from trivial because colors usually suffer severe distortions throughout the entire procedures from printing to acquiring image data. To accomplish accurate identification of colors, we need a reliable segmentation method to separate different color regions from each other, which would enable us to process the whole pixels in the region of a color statistically, instead of a subset of pixels in the region. Color image segmentation can be accomplished by performing edge detection on component image(s). In this paper, we separately detected edges on component images from RGB, HSI, and YIQ color models, and performed mathematical analyses and experiments to find out a pair of component images that provided the best edge image when combined. The best result was obtained by combining Y- and R-component edge images.

• The Journal of the Korea Contents Association
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• v.7 no.2
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• pp.109-116
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• 2007

To reduce the effect of color distortions on reading colors, it is more desirable to statistically process as many pixels in the individual color region as possible. This process may require segmentation, which usually requires edge detection. However, edges in color codes can be disconnected due to various distortions such as dark current, color cross, zipper effect, shade and reflection, to name a few. Edge linking is also a difficult process. In this paper, k-means clustering was performed on the images where edge detectors failed segmentation. Experiments were conducted on 311 images taken in different environments with different cameras. The primary and secondary colors were randomly selected for each color code region. While segmentation rate by edge detectors was 89.4%, the proposed method increased it to 99.4%. Color recognition was performed based on hue, a*, and b* components, with the accuracy of 100% for the successfully segmented cases.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.861-868
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• 2017

Near band infrared imaging technique has adopted for imaging EL2 and shallow level distributions in undoped semi-insulating LEC GaAs. This technique, which relies on the mapping of near bandgap infrared transmission, is both rapid and non-destructive. Until now no quantitative analysis has been reported for near band edge region which gives the reverse contrast on EL2 absorption images. This paper presents the spectral, spatial and temperature dependence of photoquenching forward and inverse mechanism in the band edge domain for cells and walls and for direct and inverted contrast conditions during transitory regimes. The difference in the threshold for the EL2w and EL2b defects could be attributed to the contribution of a different electrical assistance due to a different species of impurities. Quantitative analysis results show an increased density of EL2w and a small reduction of EL2b in the region of the walls where there is a high density of dislocations.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.6
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• pp.1-10
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• 2016

For the active control of a combustion instability, a change should be made in pressure fluctuation or heat release fluctuation using an acoustic driver or a secondary fuel injection. Also, to determine the location and timing of a secondary fuel injection, one needs to know the distribution of heat release fluctuation under combustion instability. In the present research, the distribution of heat release fluctuation has been experimentally measured by changing hydrocarbon fuel, inlet velocity, equivalence ratio, and acoustic forcing condition. It was confirmed that heat release fluctuation with regards to vortex shedding was significantly affected by the $Damk{\ddot{o}}hler$ number. Under the cases of the $Damk{\ddot{o}}hler$ number above approximately 4 - 5, hot spot region was generated in the leading edge of vortex and cold spot region was in the trailing edge. On the contrary, the cases of the $Damk{\ddot{o}}hler$ number below 3 showed the opposite trend.

• Polymer(Korea)
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• v.38 no.5
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• pp.640-644
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• 2014

As a process of plat panel display production, slot coating is widely used for the coating of photoresist on a wide glass substrate. A uniform coating thickness is important, and the coating uniformity is divided into nozzle and machine directions. The machine and nozzle directions coating uniformities are influenced by the operation condition of coater and flow uniformity inside the die, respectively. Non-uniform coating during steady coating process occurs according to those factors, however, non-uniform coating along the machine and nozzle directions has been observed at the beginning of coating by unsteady flow. In this study, steady and unsteady state flow simulations have been performed and compared with experiment to examine the causes of non-uniform coating. Computational results exhibited that it took a time to get a uniform pressure distribution at whole inside the die, and during this period of time edge regions showed lower exit velocity compared with center region. Subsequently edge regions had thinner coated layers than center region. However edge regions showed higher exit velocity than center region after steady state, and this made edge regions had thicker coated layer than center region.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.279-288
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• 2012

The material removal mechanism in machining is significantly affected by the cutting edge geometry. Its effect becomes even more substantial when the depth of cut is relatively small as compared to the characteristic length which represents the shape and size of the cutting edge. Conventionally, radius or focal length has been employed as the characteristic length with the assumption that the shape of cutting edge is round or parabolic. However, in reality, there could be various ways to determine the radius or focal length even for the same tool edge profile, depending on the region to be considered as cutting edge in the measured profile and the constraints to be set in constructing the best fitted circle or parabola. In this regard, the present study proposes various models to determine the characteristic length in terms of radius or focal length. Their physical compatibility are validated by carrying out 2D orthogonal cutting experiments using inserts with a wide range of characteristic length ($30{\sim}180\;{\mu}m$ in terms of radius) and then by investigating the correlation between the characteristic length and the cutting forces. Such validation is based on the common belief that the larger the characteristic length is, the blunter the cutting edge is and the higher the cutting forces are. Interestingly, the results showed that the correlation is higher for the radius or focal length obtained with a constraint that the center of best fitted circle or the focus of the best fitted parabola should be on the bisectional line of the wedge angle of tool.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.1
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• pp.29-34
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• 2002

Because do dilution (5%) in Venzotriazol distilled water and is kept UV interception departure woe which make to time each 1, 2, 5, 15, 20, 30 minutes by dip method, produced sample ore of UV interception lens. Spectrum of transmittance for each sample are measured in 320~450nm sacred grounds. The result optical absorption edge is each 403, 408, 414, 419nm regions, and absorption edge appeared in each band of 3.07, 3.04, 2.99, 2.96 eV. UV-cut lens departure solution make 2-Hydroxy-4-n-octoxyhenzophenones of 5%, 10% because solvent methanol and UV-cut lens made by Spray pyrolysis method. Transmission edge of each lens that do spray to same warelength showed sameinwavelength spectra. Being storehouse absorption edgethat increase 385, 398 and 417nm region of when do spray for 2, 4 and 6 minutes, band is accomplishing each 3.22, 3.11, 2.97 eV.

• 전자공학회논문지 IE
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• v.45 no.4
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• pp.47-53
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• 2008

A new intra-field deinterlacing algorithm with edge direction vector (EDV) in the image block is introduced. This proposed filter is suitable to the region with high motion or scene change. We first introduce an EDV, which is computed by Sobel mask used edge map, so that filer resolution of the edge direction can be acquired. The proposed EDV oriented deinterlacing system operates by identifying small pixel variations in five orientations, $26.5^{\circ}$, $45^{\circ}$, $90^{\circ}$, $135^{\circ}$, and $153.5^{\circ}$. The EDV values work as inputs of Sobel mask and return edge direction degree and confidence parameters. Based on edge direction degree and confidence parameters the missing pixel is computed. The results of computer simulations demonstrate that the proposed method outperforms a number of intra-field deinterlacing methods in the literature.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.4
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• pp.82-92
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• 2006

In the field of image recognition, research on face recognition has recently attracted a lot of attention. The most important step in face recognition is automatic eye detection researched as a prerequisite stage. Existing eye detection methods for focusing on the frontal face can be mainly classified into two categories: active infrared(IR)-based approaches and image-based approaches. This paper proposes an eye region detection method in non-frontal faces. The proposed method is based on the edge--based method that shows the fastest computation time. To extract eye region in non-frontal faces, the method uses edge orientationhistogram of the global region of faces. The problem caused by some noise and unfavorable ambient light is solved by using proportion of width and height for local information and relationship between components for global information in approximately extracted region. In experimental results, the proposed method improved precision rates, as solving 3 problems caused by edge information and achieves a detection accuracy of 83.5% and a computational time of 0.5sec per face image using 300 face images provided by The Weizmann Institute of Science.

• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.33-40
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• 2017

In this paper, we propose a text extraction method by pattern analysis on contour for effective text detection in image. Text extraction algorithms using edge based methods show good performance in images with simple backgrounds, The images of complex background has a poor performance shortcomings. The proposed method simplifies the color of the image by using K-means clustering in the preprocessing process to detect the character region in the image. Enhance the boundaries of the object through the High pass filter to improve the inaccuracy of the boundary of the object in the color simplification process. Then, by using the difference between the expansion and erosion of the morphology technique, the edges of the object is detected, and the character candidate region is discriminated by analyzing the pattern of the contour portion of the acquired region to remove the unnecessary region (picture, background). As a final result, we have shown that the characters included in the candidate character region are extracted by removing unnecessary regions.