• The korean journal of orthodontics
• /
• v.32 no.1 s.90
• /
• pp.59-69
• /
• 2002

The purpose of this study was to evaluate the reproducibility of lateral cephalometric landmarks according to radiographic image enhancement, and to contribute to the identification of cephalometric landmarks. Lateral cephalograms of ten individuals were taken and stored into computer. The images were then enhanced up to four grades by Quick Ceph Image Pro$^{TM}$ on condition that the gray-scale equalization number was 50 and the detail enhancement number was 50. After thirty two landmarks were identified on monitor images by five observers, the deviations from the mean, the distances estimated between identified points and the mean point of five identified points, were evaluated for each landmark at each enhancement grade. Through the statistical analysis, following results were obtained. 1. In case of unenhanced radiographic images, the inter-observer reproducibility of the landmarks showed a large variation. 2. The comparison of deviation from the mean according to the degree of radiographic image enhancement for each landmark showed that the inter-observer reproducibility was significantly different at 5 landmarks. 3. The landmark of pterygomaxillary fissure showed higher reproducibility at enhancement grade 1 and 2 images than at unenhanced images. So did the landmark of posterior nasal spine at enhancement grade 1 images, and the landmark of menton at enhancement grade 2, 3 and 4 images respectively. The above results suggest that the reproducibility of some landmarks can be increased by radiographic image enhancement during the identification of the lateral cephalometric landmarks on the monitor.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.3
• /
• pp.1233-1243
• /
• 2015

The contrast enhancement is great challenge in the image processing when images are suffering from poor contrast problem. Therefore, in order to overcome this problem an automatic method is proposed for contrast enhancement of natural color images. The proposed method consist of two stages: in first stage lightness component in YIQ color space is normalized by sigmoid function after the adaptive histogram equalization is applied on Y component and in second stage automatic color contrast enhancement algorithm is applied on output of the first stage. The proposed algorithm is tested on different NASA color images, hyperspectral color images and other types of natural color images. The performance of proposed algorithm is evaluated and compared with the other existing contrast enhancement algorithms in terms of colorfulness metric and color enhancement factor. The higher values of colorfulness metric and color enhancement factor imply that the visual quality of the enhanced image is good. Simulation results demonstrate that proposed algorithm provides higher values of colorfulness metric and color enhancement factor as compared to other existing contrast enhancement algorithms. The proposed algorithm also provides better visual enhancement results as compared with the other existing contrast enhancement algorithms.

• Journal of Korea Multimedia Society
• /
• v.22 no.9
• /
• pp.983-991
• /
• 2019

Histogram equalization method is a popular contrast enhancement technique. However, there are some drawbacks, namely, over-enhancement, under-enhancement, structure information loss, and noise amplification. In this paper, we propose an edge-enhancing histogram equalization algorithm while suppressing over-enhancement simultaneously. Firstly, over-enhancement is suppressed by clipping a transfer function, then, edge enhancement is achieved by using guided image filter. Experiments are carried out to evaluate the performance of the various HE algorithms. As a result, both qualitative and quantitative assessment showed that the proposed algorithm successfully suppressed over-enhancement while enhancing edges.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.6 no.2
• /
• pp.193-198
• /
• 2010

In this paper, an efficient contrast enhancement algorithm using histogram stretching is proposed. Histogram equalization (HE) and histogram stretching (HS) are effective techniques for contrast enhancement. However, HE and HS result often in excessive contrast enhancement. Proposed technique not only produces better results than those of conventional contrast enhancement techniques, but is also adaptively adjusted to image contents.

• Proceedings of the KIEE Conference
• /
• 2004.05a
• /
• pp.111-113
• /
• 2004

Histogram Equalization is the most popular algorithm for contrast enhancement due to its effectiveness and simplicity. In this paper, We propose the advanced contrast enhancement method using genetic algorithm. We propose a novel objective criterion for enhancement, and attempt finding the best image according to the respective criterion. Due to the high complexity of the enhancement criterion proposed, we employ a Genetic Algorithm. We compared our method with other enhancement techniques, like Global Histogram Equalization and Partially Overlapped Sub-Block Histogram Equalization(POSHE).

• Journal of Information Processing Systems
• /
• v.19 no.3
• /
• pp.370-376
• /
• 2023

Aiming at the problems of low image enhancement accuracy, long enhancement time and poor image quality in the traditional robot sequence motion image enhancement methods, an adaptive enhancement method for robot sequence motion image is proposed. The feature representation of the image was obtained by Karhunen-Loeve (K-L) transformation, and the nonlinear relationship between the robot joint angle and the image feature was established. The trajectory planning was carried out in the robot joint space to generate the robot sequence motion image, and an adaptive homomorphic filter was constructed to process the noise of the robot sequence motion image. According to the noise processing results, the brightness of robot sequence motion image was enhanced by using the multi-scale Retinex algorithm. The simulation results showed that the proposed method had higher accuracy and consumed shorter time for enhancement of robot sequence motion images. The simulation results showed that the image enhancement accuracy of the proposed method could reach 100%. The proposed method has important research significance and economic value in intelligent monitoring, automatic driving, and military fields.

• International conference on construction engineering and project management
• /
• 2015.10a
• /
• pp.122-126
• /
• 2015

Credit enhancement is absolutely essential for financing Independent Power Producer (IPP) projects in Asia particularly for countries whose sovereign credit rating is on non-investment grade and foreign investment is difficult to achieve. Due to nexus of agreements among varies parties in IPP project, it is hard to clearly visualize the roles of these agreements. Examples are: What credit enhancement factors are most influential to minimize the associated risks of IPP projects? Why are they powerful? What are their roles? Who are less powerful and what are the obstacles that causes them less powerful? A research is conducted to identify the credit enhancement factors for IPP projects in Asia. IPP professionals validated 27 out of 28 identified credit enhancement factors, and five factor groupings were made through factor analysis. Afterwards, network theory is applied to find the unanswered questions, which by graphical and mathematical representations show that the host government's credit enhancement, MDBs, ECAs and other parties' credit enhancement are prominent and of great importance to handle the associated risks of IPP projects in Asia

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.15 no.1
• /
• pp.35-44
• /
• 2015

The main purpose of image enhancement is to improve certain characteristics of an image to improve its visual quality. This paper proposes a method for image contrast enhancement that can be applied to both medical and natural images. The proposed algorithm is designed to achieve contrast enhancement while also preserving the local image details. To achieve this, the proposed method combines local image contrast preserving dynamic range compression and contrast limited adaptive histogram equalization (CLAHE). Global gain parameters for contrast enhancement are inadequate for preserving local image details. Therefore, in the proposed method, in order to preserve local image details, local contrast enhancement at any pixel position is performed based on the corresponding local gain parameter, which is calculated according to the current pixel neighborhood edge density. Different image quality measures are used for evaluating the performance of the proposed method. Experimental results show that the proposed method provides more information about the image details, which can help facilitate further image analysis.

• Korean Journal of Human Ecology
• /
• v.23 no.2
• /
• pp.281-292
• /
• 2014

This study was designed to examine the influence of gratitude enhancement program on preschoolers' aggression perceived by their teacher and mother. The subjects in this study were 40 four-year-old children in kindergarten in U city. This study employed a pre/post-test control group design, and so all subjects were assigned to an experimental group(gratitude enhancement program) or comparative group(general education program according to the year curriculum). Preschoolers' aggression was measured by the teacher and mother of the subjects and the collected data were analyzed by independent and paired t-test. This study also computed Cohen's d to estimate effect size of gratitude enhancement program on preschoolers' aggression. The findings of this study were as follows. Firstly, gratitude enhancement program and general education program were all effective in reducing preschoolers' aggression(aggression against things, verbal aggression and total aggression) perceived by their teacher except of aggression against others. But gratitude enhancement program was more effective than general education program in reducing these sort of aggression. Meanwhile, only gratitude enhancement program was effective in reducing preschoolers' aggression against others. Secondly, gratitude enhancement program was effective in reducing preschoolers' aggression(aggression against things, aggression against others, verbal aggression and total aggression).

• Journal of Families and Better Life
• /
• v.23 no.1 s.73
• /
• pp.1-18
• /
• 2005

The purpose of this study was to construct the Marital Relationship Enhancement Program based on PREP(Prevention and Relationship Enhancement Program), and to examine the effect of it for couples in the early marriage stage. To perform this program, six session of time-limited(two hour) were carried out experimental group. and subjects were assigned to experimental group(N=6 couples) and control group(N=6 couples). Scales of PREPARE II (PREmarital Personal And Relationship Evaluation), Couple Communication Scales and Commitment Scales were used as pre-post-follow instruments of this study. Major finding were as follows : 1. Marital Relationship Enhancement Program for couples in the early marriage stage has meaningful consequences for the improvement of participants' couple relationship. 2. Marital Relationship Enhancement Program had meaningful consequence for the improvement of participants' realistic expectation of marriage, communication and conflict resolution skills and leisure activities. These positive effects maintained at follow-up. However, it hadn't meaningful consequence for the improvement of participants' marital commitment. 3. Marital Relationship Enhancement Program had also meaningful consequence for the improvement of the wives' realistic expectation of marriage, communication and conflict resolution skills and leisure activities, of the husbands' communication and conflict resolution skills.