• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.5
• /
• pp.1147-1154
• /
• 2011

Auto exposure (AE) in image signal processor (ISP) controls brightness of input image to the proper brightness when it is too dark or bright. But conventional AEs often fail to get proper brightness since AE controls only average brightness of image. Especially in applications that require object recognition, it cannot be solved the problem by AE of ISP. In this paper proposes Histogram Equalization (HE) processes that is the alternative of AE. It also proposes proper method to realize hardware and compensate HE problems conventional by using simple calculation.

• Journal of the Korea Society of Computer and Information
• /
• v.24 no.11
• /
• pp.71-78
• /
• 2019

Most 3D displays that are currently in the market adopt the binocular disparity method creating a different image for the left and right eye for a 3 dimensional effect. However, commercialized 3D image output devices lack in performance making it uncomfortable for the viewer and restrict the viewer to certain positions. In this paper, we propose a single-cell polarized lens type stereoscopic system which has a smaller viewing angle and reduced crosstalk, with improved light penetration compared to existing double-cell structures; and analyzed the single-cell polarized lens type stereoscopic system properties, and conducted an effect analysis of performance improvement compared to the dual-cell type. Results showed that the single-cell type had a 25% improved performance, and the 3D crosstalk index which is an important index for quality characteristics of stereoscopic systems, increased over about 37%, compared to the dual-cell type.

• Journal of the Korea Convergence Society
• /
• v.7 no.6
• /
• pp.1-6
• /
• 2016

In this paper, we propose an image enhancement method for vehicle recorder by dividing the images into sub-images and finding local histograms of the sub-images. The proposed method includes the following steps. Firstly, the input image is divided into ($N{\times}M$) pieces. And the sub-images are used to make groups using the adjacent piece-images (eg. piece-imagei,j, piece-imagei,j+1, piece-imagei+1,j and piece-imagei+1,j+1). Secondly, the contrast enhancement processes are executed using the local histogram of the sub-images. Finally, overall image is reconstructed by using a transfer function that reflects the characteristics of the sub-image. The proposed method might achieve more enhanced images for vehicle recorder by suppressing excessive image contrast.

• Journal of Korea Multimedia Society
• /
• v.12 no.8
• /
• pp.1082-1088
• /
• 2009

Fundus images are highly useful in evaluating patients' retinal conditions in diagnosing eye diseases. In particular, vessel regions are essential in diagnosing diabetes and hypertension. In this paper, we used top-hat filter to compensate for non-uniform background. Image contrast was enhanced by using contrast limited adaptive histogram equalization (CLAHE) method. Hessian matrix was next applied to detect vessel regions. Results indicate that our method is 1.3% more accurate than matched filter method. Our proposed method is expected to contribute to diagnosing eye diseases.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.12
• /
• pp.2398-2405
• /
• 2007

This paper proposes a contrast enhancement technique which stretches the intensity surfaces of image to improve the quality of the digital photos. The proposed method enhances the contrast of image by stretching the intensity surface of the original image to the maximum range of the output image in proportion to the distances between the original intensity surface and upper, lower intensity surface, respectively. The upper and lower intensity surfaces are generated from the original intensity surface by gaussian smoothing. In the experiments, digital color images in a variety of illumination conditions were used and the proposed method was compared with other several existed image enhancement algorithms, which are histogram stretching, surface stretching, histogram equalization, gamma correction and retinex. It was proved that the experimental results were more natural visually without deterioration of gradation.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1991.10a
• /
• pp.205-217
• /
• 1991

본 연구의 목적은 포항제철소 스테인레스 냉연공장 가동계획에 의거 stainless소둔산세공장 H-CPL에서 냉연공장 정정 line까지의 material flow 및 설비운영상 제약상항을 simulation하므로서 생산성 향상에 필요한 조업대비 기준 및 문제점을 도출하여 정상조업도 조기 달성에 기여하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.1
• /
• pp.28-35
• /
• 2014

Surveillance cameras in national border and coastline area often occur the video distortion because of rapidly changing weather and light environments. It is positively necessary to enhance the distorted video quality for keeping surveillance. In this paper, we propose an adaptive video enhancement algorithm in the various environment changes. To solve an unstable performance problem of the existing method, the proposed method is based on Retinex algorithm and uses enhanced curves which is adapted in foggy and low-light conditions. In addition, we mixture the weighted HSV color model to keep color constancy and reduce noise to obtain clear images. As a results, the proposed algorithm improves the performance of well-balanced contrast enhancement and effective color restoration without any quality loss compared with the existing algorithm. We expect that this method will be used in surveillance camera systems and offer help of national defence with reliability.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2015.10a
• /
• pp.1491-1493
• /
• 2015

본 논문에서는 GPU를 이용하여 x-ray영상의 질을 개선시키기 위해 라플라시안 피라미드 방법을 제시한다. 의료영상에서 중요시하는 특징의 추출을 위해 원영상을 다중레벨의 부영상으로 신호를 분해하며, 각 레벨에서 가우시안 스무딩 함수를 사용하여 영상의 대비를 확장시킨다. 분해된 영상을 기반으로 전체영상을 재구성하여 영상의 질을 향상시키게 된다. 이러한 과정은 많은 계산을 필요로하며, 효과적이고 바른 처리를 위해 GPU를 사용한다., 결과에서 GPU를 이용한 cuda 프로그램이 효과적으로 동작하며, 영상의 질을 향상시킴을 보인다.

• Journal of Broadcast Engineering
• /
• v.24 no.2
• /
• pp.292-298
• /
• 2019

In this paper, we show how to provide high quality image service using cloud server and image quality enhancement algorithm. In other words, based on the concept of ViVa (Video Value Addition) proposed in the paper, we propose an improved system compared to the existing streaming service by providing a high-quality video with the transmission bit rate and calculation amount necessary to serve low-quality images.

• Journal of Broadcast Engineering
• /
• v.22 no.4
• /
• pp.496-508
• /
• 2017

In this paper, we propose a Tone Mapping Operator (TMO) that preserves global contrast and precisely preserves boundary information. In order to reconstruct a High Dynamic Range (HDR) image to a Low Dynamic Range (LDR) display by using Threshold value vs. Intensity value (TVI) based on Human Visual System (HVS) and contrast value. As a result, the global contrast of the image can be preserved. In addition, by combining the boundary information detected using Guided Image Filtering (GIF) and the detected boundary information using the spatial masking of the Just Noticeable Difference (JND) model, And improved the perceived image quality of the output image. The conventional TMOs are classified into Global Tone Mapping (GTM) and Local Tone Mapping (LTM). GTM preserves global contrast, has the advantages of simple implementation and fast execution time, but it has a disadvantage in that the boundary information of the image is lost and the regional contrast is not preserved. On the other hand, the LTM preserves the local contrast and boundary information of the image well, but some areas are expressed unnatural like the occurrence of the halo artifact phenomenon in the boundary region, and the calculation complexity is higher than that of GTM. In this paper, we propose TMO which preserves global contrast and combines the merits of GTM and LTM to preserve boundary information of images. Experimental results show that the proposed tone mapping technique has superior performance in terms of cognitive quality.