https://scholar.dgist.ac.kr/handle/20.500.11750/4347 2026-04-04T07:33:45Z https://scholar.dgist.ac.kr/handle/20.500.11750/46982 Title: Image Broadcasting for Heterogeneous User Devices in MIMO Networks Author(s): Jang, Soyoung; Chang, Seok-Ho; Kim, Minyeong; Cho, Sunghyun Abstract: This paper considers a multimedia broadcasting scenario in which two types of heterogeneous users with different display resolutions and different numbers of antennas stay in the service area. We propose an image broadcasting scheme that uses the image super-resolution (SR) techniques, spatial diversity, and diversity-multiplexing tradeoff (DMT) achieving codes. The proposed scheme broadcasts a low-resolution (LR) image to two types of users, along with residual pixel-error map containing high-frequency details of high-resolution (HR) image. Then, a user retaining an HR screen employs SR to reconstruct an HR image from the received LR image, and exploits the residual map to further enhance the image quality. Our scheme properly trains the neural network models of the deep learning-based SR by taking into account the source coding rates of the images. Considering the relationship between the number of antennas and screen resolution, based on hardware space of user devices, the proposed scheme encodes an LR image with spatial diversity, and encodes residual map with DMT-achieving codes. Numerical evaluation shows that our scheme significantly outperforms the baseline strategy that broadcasts either HR or LR images. © 2019 IEEE. 2019-05-21T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/13198 Title: 360도 영상 재생 방법 및 장치 Author(s): 조성현; 강경국 Abstract: 본 발명은 360도 영상 재생 방법 및 장치에 관한 것이다. 본 발명의 일 실시예에 따른 360도 영상 재생 방법은 360도 영상의 일부 영역을 재생하는 방법으로서, 복수의 360도 영상 프레임 각각의 복수 픽셀에 대해, 옵티컬 플로우(optical flow)과 돌출성(saliency)을 각각 계산하는 전처리 단계; 계산된 옵티컬 플로우와 돌출성을 이용하여 각 360도 영상 프레임에서의 가상 카메라 경로를 설정하는 설정 단계; 및 설정된 가상 카메라 경로를 따라 360도 영상의 일부 영역을 재생하는 재생 단계;를 포함한다. https://scholar.dgist.ac.kr/handle/20.500.11750/13048 Title: 동영상 수평 조정 시스템, 방법 및 컴퓨터 프로그램 Author(s): 원주철; 조성현 Abstract: 본 발명의 일 실시예에 따르면 사용자 단말로부터 입력 비디오를 획득하는 비디오 입력부; 회전 추정 네트워크를 이용하여 상기 입력 비디오의 회전각의 초기 추정치를 산출하는 제1 회전각 추정부; 이미지의 복수개 로컬영역별 회전각의 추정을 이용하는 오류모델에 기반하여 상기 초기 추정치로부터 최종 회전각을 추정하는 제2 회전각 추정부; 상기 최종 회전각에 기반하여 상기 입력 비디오의 프레임을 역회전시키는 프레임 회전부; 를 포함하는 동영상 수평 조정 시스템이 제공된다. https://scholar.dgist.ac.kr/handle/20.500.11750/12919 Title: Video Upright Adjustment and Stabilization Author(s): Won, Jucheol; Cho, Sunghyun Abstract: We propose a novel video upright adjustment method that can reliably correct slanted video contents. Our approach combines deep learning and Bayesian inference to estimate accurate rotation angles from video frames. We train a convolutional neural network to obtain initial estimates of the rotation angles of input video frames. The initial estimates are temporally inconsistent and inaccurate. To resolve this, we use Bayesian inference. We analyze estimation errors of the network, and derive an error model. Based on the error model, we formulate video upright adjustment as a maximum a posteriori problem where we estimate consistent rotation angles from the initial estimates. Finally, we propose a joint approach to video stabilization and upright adjustment to minimize information loss. Experimental results show that our video upright adjustment method can effectively correct slanted video contents, and our joint approach can achieve visually pleasing results from shaky and slanted videos. © 2019. The copyright of this document resides with its authors. It may be distributed unchanged freely in print or electronic forms. 2019-09-09T15:00:00Z