• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.273-276
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• 1997

Seeing is an intelligent act. Retina is the most important part among the components of eye which is comprised of iris, pupil, lens, optic disk, and so forth. Because retina acts like a photo receiver to detect light from every object, if damaged, animals have a severe problem to live along with themselves and sometimes they lose their sight. In the ophthalmology, doctors use special instrument to see exact retina image of object and operate the surgery by rotating focus control knob. In this study, a basic test is done to achieve the auto focus control instrument. Specially made sledge and attenuator are installed on the optic bed to change the distance and laser power between the first reflective mirror and the second one. Control panel which is compiled by Visual C t t to control stepping motors ,laser power and photodiode are implemented with ADA-board.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.82-87
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• 1998

Laser printer, faximile and copy machine are a few examples of OA(office automation) system. In such a system, the reflecting mirror has been employed for transmitting a target image to optical device. Therefore, to develope a good quality of optical system, the quality control of optical mirror was required. In recent years, considerable efforts have been directed toward the development of automated optical glass inspection system because the inspection is eye-fatigue and monotonous job for humans to perform. In this paper, we propose a inspection system applying algorithm of image processing for detecting defects of optical glass such as pinhole, scratch. From the experiments, the proposed inspection system shows reliable results.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.1045-1048
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• 1999

In this paper, we calculate the moving velocity of viewer by using two eye images obtained at different time through the camera. This process is necessary for future 3D display technique, in which moving viewer can see 3D image continuously We firstly extract two eyes image and calculate the pixel coordinate of center point between two eyes. Next, we calculate the moving velocity in two dimension by comparing two center point coordinates obtained at different time.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.689-692
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• 2002

To show a retina shape and thickness on the computer, a laser has been used in Scanning Laser Ophthalmoscope (SLO) equipment using the travelling difference. This method requires exact synchronize control of laser travelling in optic system to show this image. In this study, a synchronize control of the galvanometer to make 3-dimentional retina image. To obtain a clear 3-dimentional image, this exact synchronism is very Important for making perfect plane scanning.

• Journal of Biomedical Engineering Research
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• v.11 no.1
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• pp.31-38
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• 1990

Image correction of the fluorescein angiogram with the low contrast and geometrically distorted is studied. The procedure is divided into two steps : A template matching step and a geometrical transformation step. Based on the sequential similiarity detection algorithm, more Improved matching results are obtained with edge enhanced image. For the reference points and the corresponding matchimg points, the geometrical transformationss by the use of the average value of the X, Y translational shifts and a pair of these points, respectively are described. Then the corrected images are obtained using bilinear interpolation. It is proven that the usefullness of this study for the image correction of the ocular fundus fluoresceln angiogram with low contrast and geometrically distorted mainly due to the eye movements.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.3
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• pp.294-303
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• 1999

To improve the visual servoing performance, several strategies were proposed in the past such as redundant feature points, using a point with different height and weighted selection of image features. The performance of these visual servoing methods depends on the configuration between the camera and object. And redundant feature points require much computation efforts. This paper proposes the visual servoing method based on the disturbance obsever, which compensates the upper off-diagonal component of image feature jacobian to be the null. The performance indices such as sensitivity for a measure of richness, sensitivity of the control to noise, and comtrollability are shown to be improved when the image feature Jacobian is given as a block diagonal matrix. Computer simulations are carried out for a UUMA560 robot and show some results to verify the effectiveness of the proposed method.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.177-180
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• 2002

To show a retina shape and thickness on the computer monitor, a laser has been used in Scanning Laser Ophthalmoscope(SLO) equipment using the travelling difference. This method requires exact synchronous control of laser travelling in optic system to show a clear 3-dimensional image of retina. To obtain this image, this exact synchronism is very important for making the perfect plane scanning. In this study, a synchronous control of the galvanometer using deadbeat torque observer to make 3-dimensional retina image is presented. For the more, a very simple mathematical model of the galvanometer is approved by experimental result.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.285-291
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• 2022

With the growing exchange of data between individuals and institutions through various electronic communication, valuable data protection is in high demand to ensure that it is not hacked and that privacy is protected. Many security techniques, such as encryption and steganography, have emerged to prevent security breaches. The purpose of this research is to integrate cryptographic and steganography techniques to secure text message sending. The Rijndael algorithm was used to encrypt the text message, and the Least Significant Bit algorithm was also used to hide the encrypted message in a color image. Experiments on the suggested method have proven that it can improve the security of sent messages due to the human eye's inability to identify the original image from the image after it has been covered, as well as the encryption of the message using a password.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.351-354
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• 2011

This paper discusses on facial features extraction based on proposed skin color model. Different parts of face from input image are segmented based on skin color model. Moreover, this paper also discusses on concept to detect the eye and mouth position on face. A height and width ratio (${\delta}=1.1618$) based technique is also proposed to accurate detection of face region from the segmented image. Finally, we have cropped the desired part of the face. This exactly exacted face part is useful for face recognition and detection, facial feature analysis and expression analysis. Experimental results of propose method shows that the proposed method is robust and accurate.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.3
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• pp.95-101
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• 2006

A face detection plays an important role in face recognition, video surveillance, and human computer interaction. In this paper, we propose a progressive threshold method to detect human faces in real time. The consecutive face images are acquired from camera and transformed into YCbCr color space images. The skin color of the input images are separated using a skin color filter in the YCbCr color space and some candidated face areas are decided by connected component analysis. The intensity equalization is performed to avoid the effect of many circumstances and an arbitrary threshold value is applied to get binary images. The eye area can be detected because the area is clearly distinguished from others in the binary image progressive threshold method searches for an optimal eye area by progressively increasing threshold from low values. After progressive thresholding, the eye area is normalized and verified by back propagation algorithm to finalize the face detection.