• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.66-75
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• 2010

We proposed an occupant sensing system using single video camera and ultrasonic sensor for the advanced airbag. To detect the occupant form and the face position in real-time, we used the skin color and motion information. We made the candidate face block image using the threshold value of the color difference signal corresponding to skin color and difference value of current image and previous image of luminance signal to gel motion information. And then it detects the face by the morphology and the labeling. In case of night without color and luminance information, it detects the face by using the threshold value of the luminance signal get by infra-red LED instead of the color difference signal. To evaluate the performance of the proposed occupant detection system, it performed various experiments through the setting of the IEEE camera, ultrasonic sensor, and infra-red LED in vehicle jig.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.574-577
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• 2011

H.264/AVC는 휘도 신호 $4{\times}4$ 블록을 위하여 9개의 화면 내 예측모드를 사용한다. 예측 모드는 8개의 방향성을 가진 모드와 하나의 비방향성 DC 모드가 있다. 휘도 신호 $16{\times}16$ 블록에서는 4가지의 예측 모드가 있으며 색차 신호 $8{\times}8$ 에서도 4개의 예측모드를 사용한다. 이러한 예측 모드들 중 최적의 예측 모드를 선택하기 위하여, 부호화기는 선택 가능한 모든 예측 모드의 율-왜곡 비용을 계산한 후, 최적의 율-왜곡 비용을 가진 예측 모드를 사용하여 부호화를 수행한다. 따라서 H.264/AVC의 화면 내 예측 과정은 많은 계산 복잡도를 가진다. 특히 하이 프로파일에서는 휘도 신호 $8{\times}8$ 블록이 화면 내 예측을 위해서 고려되므로 더욱 많은 계산 복잡도를 요구한다. 이에 본 논문은 H.264/AVC 하이 프로파일의 화면 내 예측의 부호화 계산 복잡도를 줄이는 방법을 제안한다. 현재 매크로 블록의 분산을 계산한 후, 이를 이용하여 율-왜곡 최적화에 후보로 사용되어지는 블록 모드를 결정하고, 각 블록 모드에서 제공하는 예측 모드들을 효율적으로 선택하는 방법을 연구 개발하였다. 제안된 방법은 기존 H.264/AVC 참조 소프트웨어인 JM13.1 부호화 시간 대비 약 83%의 연산시간이 감소하는 결과를 보였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.118-124
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• 2001

In this paper, we proposed the novel digital watermarking for color still image using the characteristics of human visual system and the distribution of DCT coefficients. We insert watermark signal in the chromatic components of YCrCb color space according the characteristics of the human visual system that chromatic component are less sensitive than achromatic components. In order to extract the watermark signal, we use the relationship among the DCT coefficients of watermarked image without using original one. Simulation results show that the proposed watermarking method is better quality on invisibility than the conventional methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.511-516
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• 2006

In this raper, we propose the Sequentiel Couleur Avec Memoire or Sequential Color with Memory (SECAM) video encoder system using modified anti-cloche filters and the SECAM video decoder system using a band pass filter (BPF) and an error-free square root. The SECAM encoder requires an anti-cloche filter recommended by International Telecommunication Union-Recommendation (ITU-R) Broadcasting service Television (BT) 470. However, the design of the anti-cloche filter is difficult because the frequency response of the anti-cloche filter is very sharp around rejection-frequency area. So, we convert the filter into a hish pass filter (HPF) by shifting the rejection frequency of 4.286MHz to 0Hz frequency. The design of HPF becomes very easy, compared to that of the anti-cloche filter. The proposed decoder also uses an error-free square root, two differentiators and trigonometric functions to extract color-component information of Db and Dr accurately from frequency modulation (FM) signals in SECAM systems. Also, the BPF in decoder it used for removing color noise in chrominance and dividing CVBS into chrominance and luminance. The proposed systems are experimentally demonstrated with Altera FPGA APEX20KE EP20K1000EBC652-3 device and TV sets.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.269-274
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• 2004

The marine electronic system for safe navigation such as ECDIS has been contributing to increase the safety of navigation, decreasing the mariner's load of navigation. The ECDIS should be developed and approved by international standard of IMO for performance standard and IEC for type-approval method and required results. However, these standards have some ambiguities for us not to directly adopt them for real approval system, so we should analyze them for more clear meaning and prepare our own detail standard for type-approval system. The first thing to do for the goal of this research was to analyze the standard in detail and make ambiguity be cleared in our own standards, considering each test item in view of test methodology. For the result of analysis we could develop more evident and detail type-approval standard for each test item with test technology needed. Especially, we developed the colour differentiation test process of ECDIS monitor, which include the colour differentiation formula derived from CIE colour scheme. Several test items require sensor informations of navigation equipment compatible with IEC 61162. We also developed the signal simulator for general messages of IEC 61162 that must be provided. Additionally, the type-approval processes and standards for Back-up arrangement and RCDS mode were developed.

• Journal of IKEEE
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• v.25 no.1
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• pp.139-147
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• 2021

This paper introduces an image decomposition-based deep learning method and loss function to improve low-light images. In order to remove color distortion and halo artifact, illuminance channel of an input image is decomposed into reflectance and luminance channels, and a decomposition-based multiple structural deep learning process is applied to each channel. In addition, a mixed norm-based loss function is described to increase the stability and remove blurring in reconstructed image. Experimental results show that the proposed method effectively improve various low-light images.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.578-581
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• 2011

H.264/AVC에서는 율-왜곡 최적화 기법을 사용하여 부호화 성능을 이전 보다 대폭 향상시켰다. 율-왜곡 최적화 기법은 선택할 수 있는 모든 코딩 모드들의 비용을 계산한 후, 최소의 비용을 가진 모드를 선택하여 부호화를 한다. 따라서 코딩 모드들이 많아질수록 복잡도 역시 증가하며, 기존 표준보다 다양한 코딩모드를 지원하는 H.264에서는 복잡도가 더 많이 증가한다. 본 논문에서는 SAHTD(Sum of Absolute Hadamard Transform Difference)를 이용하여 화면 내 모드 결정부에서 빠른 화면내 모드 결정을 하면서도 압축 손실이 적게 발생하는 방법을 제시하였다. 휘도 신호 $16{\times}16$블록, 휘도 신호 $4{\times}4$블록, 색차 신호 $8{\times}8$블록 모두 SAHTD를 기준으로 최적의 모드가 결정된다. 휘도 신호 $16{\times}16$블록에서 SAHTD값에 따라 $4{\times}4$블록 부호화 과정을 조기 종결이 가능하게 하는 것과, 휘도 신호 $4{\times}4$에서는 SAHTD 값이 가장 낮은 3개의 모드와 MPM(Most Probable Mode)을 후보 모드로 선택하여 율-왜곡 최적화를 수행하는 방식이 사용되었다. MPM이 SAHTD값이 가장 낮을 경우 MPM이 휘도신호 $4{\times}4$블록의 최적의 모드로 선택되고 종료된다. JM 참조 소프트웨어를 통한 실험결과 제안된 기법은 기존 JM의 방식에 비해 화면 내 프레임의 부호화 시간의 84.7% 감소와 0.049dB의 PSNR 감소율, 0.595%의 비트 증가율을 보여주었다.

• Journal of Korea Multimedia Society
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• v.13 no.5
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• pp.710-721
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• 2010

Recently, for the advancement of embedded technology about mobile device, a new kind of service, mash-up is appeared. It is service or application combining multimedia content making tool or device and web-GIS(geographic information system) service in the mobile environment. This service can be ease to use for casual user and can apply in various ways. So, It is served in web 2.0 environment actively. But, in the mashup service, because generated multimedia contents linked with web map are new type of multimedia contents which include user's migration routes in the space such as GPS coordinates. Thus, there are no protection ways for intellectual property created by GIS web-map service users and user's privacy. In this paper, we proposed a location and user information hiding scheme for GIS web-map service. This scheme embeds location and user information into a picture that is taken by camera module on the mobile phone. It is not only protecting way for user's privacy but is also tracing way against illegal photographer who is peeping person through hidden camera. And than, we also realized proposed scheme on the mobile smart phone. For minimizing margin of error about location coordinate value against contents manipulating attacks, GPS information is embedded into chrominance signal of contents considering weight of each digit about binary type of GPS coordinate value. And for tracing illegal photographer, user information such as serial number of mobile phone, phone number and photographing date is embedded into frequency spectrum of contents luminance signal. In the experimental results, we confirmed that the error of extracted information against various image processing attacks is within reliable tolerance. And after file format translation attack, we extracted embedded information from the attacked contents without no damage. Using similarity between extracted one and original templete, we also extracted whole information from damaged chrominance signal of contents by various image processing attacks.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.77-83
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• 2016

This paper presents an adaptive retinex algorithm using skewness for contrast enhancement of color images. In order to estimate the degree of low contrast of an image, skewness of luminance of an observed image is used to define a parameter, and a non-linear function is proposed to compensate the reflectance using the parameter and estimated reflectance. In addition, determination of gain and offset of the non-linear function is addressed using statistics of the estimated reflectance. The relation between an observed luminance and the compensated luminance is used to compensate color components with the reduction of computational cost. The experimental results show that the proposed algorithm has the capability to effectively improve the contrast without color distortion.

• Journal of Korea Multimedia Society
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• v.9 no.11
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• pp.1455-1464
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• 2006

In this paper, we propose an adaptive image enhancement algorithm. The proposed algorithm is classified with the MIE technique for intensity enhancement of input image and MSE techniques for saturation enhancement. The MIE technique is proposed to control the gamut mapping problem and a sudden change in image-brightness while Luminance signal is processing, The MSE techniques are proposed to control de-saturation or over-saturation while chrominance signal is processing. The proposed algorithm is focused on processing preference color for human vision in order to generate better image quality than the algorithms focused on processing uniformly to whole images, This algorithm can be applied to a monitor, TV and other display devices for high quality image.