• Proceedings of the Korean Information Science Society Conference
• /
• 2001.04a
• /
• pp.187-189
• /
• 2001

In this study, the Web Camera System is implementation and simulated on two different architectures. In the one architecture, a Web-server and Camera-server are implemented on the same system, and the system transfers motion picture which compressed to JPEG file to users on the WWW(World Wide Web). In the other architecture, the Web-server and Camera-server are implemented on different systems, and the motion picture is transferred from the Camera-server to Web-server, and finally to users. In order to compare system performance between two architecture, data traffic is measured and simulated in the unit of byte per second and frame per second.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.8
• /
• pp.75-84
• /
• 2004

In this paper, we proposed an efficient hardware architecture of line-based lifting algorithm for Motion JPEG2000. We proposed a new architecture of a lifting-based filtering cell which has an optimized and simplified structure. It was implemented in a hardware accommodating both (9,7) and (5,4) filter. Since the output rate is linearly proportional to the input rate, one can obtain the high throughput through parallel operation simply by adding the hardware units. It was implemented into both of ASIC and FPGA The 0.35${\mu}{\textrm}{m}$ CMOS library from Samsung was used for ASIC and Altera was the target for FRGA. In ASIC, the proposed architecture used 41,592 gates for the lifting arithmetic and 128 Kbit memory. For FPGA it used 6,520 LEs(Logic Elements) and 128 ESBs(Embedded System Blocks). The implementations were stably operated in the clock frequency of 128MHz and 52MHz, respectively.

• Journal of Broadcast Engineering
• /
• v.9 no.2
• /
• pp.119-130
• /
• 2004

We have developed a prototype super-high-definition (SHD) digital cinema distribution system that can store, transmit, and display eight-million-pixel motion pictures that have the image quality of a 35-mm film movie. The system contains a movie server, a real-time decoder, and an SHB projector. Using a Gigabit Ethernet link and TCP/IP, the server transmits JPEG2000 compressed motion picture data streams to the decoder at transmission speeds as high as 300 Mbps. The received data streams are decompressed by the decoder, and then projected onto a screen via the projector. By using an enlarged TCP window, multiple TCP streams, and a shaping function to control the data transmission quantity, we achieved real-time streaming of SHD movie data at about 300 Mbps between Chicago and Los Angeles, a distance of more than 3000 km. We also improved the decoder performance to show movies with Image qualities of 450 Mbps or higher. Since UDP is more suitable than TCP for fast long-distance streaming, we have developed an SHD digital cinema UDP relay system, in which UDP is used for transmission over a fast long-distance network. By using four pairs of server-side-proxy and decoder-side-proxy, 450-Mbps movie data streams could be transmitted.

• Proceedings of the KSME Conference
• /
• 2000.04b
• /
• pp.655-660
• /
• 2000

Animation technique from the PIV database is particularly emphasized to give macroscopic and quantitative description of complex flow fields. This paper shows animation construction and application example for the post-processing of PIV data. As examples, first case is a pitching airfoil immersed in tree surface water circulating tunnel. Second case is a wake of a model-ship. Third case of PIV data is a large scale surface flow field. Obtained images are processed in time sequence by PIV exclusive routines where an efficient and reliable cross correlation algorithm is included for vector identification. All. animation Jobs are implemented completely on single personal computer environment. Compressed digital images are obtained initially by Motion-JPEG board and various An files are finally obtained through graphic processes.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.45-45
• /
• 2000

This paper proposes a remote control system that combines computer network and an autonomous mobile robot. We control remotely an autonomous mobile robot with vision via the internet to guide it under unknown environments in the real time. The main feature of this system is that local operators need a World Wide Web browser and a computer connected to the internet communication network and so they can command the robot in a remote location through our Home Page. The hardware architecture of this system consists of an autonomous mobile robot, workstation, and local computers. The software architecture of this system includes the server part for communication between user and robot and the client part for the user interface and a robot control system. The server and client parts are developed using Java language which is suitable to internet application and supports multi-platform. Furthermore, this system offers an image compression method using motion JPEG concept which reduces large time delay that occurs in network during image transmission.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.2C
• /
• pp.113-123
• /
• 2007

In Ubiquitous communication environment, various conversions of images are essential, and most digital images are compressed by standard methods such as the Joint Photographic Expert Group (JPEG) and Motion Picture Expert Group (MPEG) which are based on the discrete cosine transform (DCT). In this paper, various image resizing algorithms in the DCT domain are analyzed, and a new image resizing algorithm, which shows superior performance compared with the conventional methods, is proposed. For arbitrary-ratio image resizing in the DCT domain, several blocks of $8{\times}8$ DCT coefficients are converted into one block using the conversion formula in the proposed algorithm, and the size of the inverse discrete cosine transform (IDCT) is decided optimally. The performance is analyzed by comparing the peak signal to noise ratio (PSNR) between original images and converted images. The performance of the proposed algorithm is better than that of the conventional algorithm, since the correlation of pixels in images is utilized more efficiently.

• KIPS Transactions on Software and Data Engineering
• /
• v.10 no.10
• /
• pp.421-428
• /
• 2021

The High Efficiency Image File Format (HEIF) is an MPEG-developed image format that utilizes the video codec H.265 to store still screens in a single image format. The iPhone has been using HEIF since 2017, and Android devices such as the Galaxy S10 have also supported the format since 2019. The format can provide images with good compression rates, but it has a complex internal structure and lacks significant compatibility between devices and software, making it not popular to replace commonly used JPEG (or JPG) files. However, despite the fact that many devices are already using HEIF, digital forensics research regarding it is lacking. This means that we can be exposed to the risk of missing potential evidence due to insufficient understanding of the information contained inside the file during digital forensics investigations. Therefore, in this paper, we analyze the HEIF formatted photo file taken on the iPhone and the motion photo file taken on the Galaxy to find out the information and features contained inside the file. We also investigate whether or not the software we tested support HEIF and present the requirement of forensic tools to analyze HEIF.

• The KIPS Transactions:PartC
• /
• v.9C no.1
• /
• pp.9-16
• /
• 2002

As existing analog video surveillance systems could save and retrieve data only in a limited space within short distance, it had many constraints in developing into various application systems. However, on the back of development of the Internet and computer technologies, digital video surveillance systems can be controlled from a remote location by web browser without space limits. Moreover, data compression and management technologies with Index Search algorithm make it possible to efficiently handling, storing, and retrieving a large amount of data and further motion detection algorithm enhances a recording speed and efficiency for a practical application, that is, a practical remote recordable video surveillance system using our efficient algorithms as mentioned, called WebCam. The WebCam server system can intelligently record and save video images digitized through efficient database management, monitor and control cameras in a remote place through user authentication, and search logs.

• Proceedings of the Korea Contents Association Conference
• /
• 2007.11a
• /
• pp.837-841
• /
• 2007

최근 영상을 중심으로 여러 형태의 정보를 결합하여 저장하거나 전송하는 멀티미디어가 많은 관심을 받고 있다. 현재 카메라와 관련된 동영상 캡처기술은 Motion JPEG이 주류를 이루고 있으며, 텔레비전, DMB 등의 방송 분야 및 DVD, VCR 분야에서는 MPEG-2, MPEG-4, H.264 및 WMV9 등의 압축 코덱이 채용되고 사용되고 있다. 그러나 이러한 다양한 영상 표준방식은 디코딩시 호환성 문제가 발생하게 되고 이에 따라 통합 코덱 연구가 필요하다. 이에 본 논문은 일반적 스텝 양자화외에 데드존 양자화를 사용하고 "$4{\times}4$", "$4{\times}8$", "$8{\times}4$", "$8{\times}8$"의 다양한 블록크기의 변환을 지원하는 VC-1을 기반으로 한 ITIQ C언어를 통해 시뮬레이션하고 최적화된 결과를 VHDL로 구현하여 향후 통합코덱 연구에 응용 가능하도록 연구 및 분석평가 하였다. 설계결과 4:2:0의 YCbCr포맷의 최초 $16{\times}16$블록을 복원하는데 483~510클록이 소요되었고 Xilinx XCVPC100 FF1696-6 환경에서 93,128개의 게이트 수와 71.469MHz의 동작속도를 나타내었다. 이는 640*480 크기의 컬러영상을 디코딩 하는데 프레임 당 최대 0.0074초가 소요됨을 의미하며 초당 30프레임의 영상에서도 0.222초면 디코딩이 가능한 결과이다.

• Journal of the Korea Computer Graphics Society
• /
• v.25 no.3
• /
• pp.1-9
• /
• 2019

The image obtained from systems such as autonomous driving cars or fire-fighting robots often suffer from several degradation such as noise, motion blur, and compression artifact due to multiple factor. It is difficult to apply image recognition to these degraded images, then the image restoration is essential. However, these systems cannot recognize what kind of degradation and thus there are difficulty restoring the images. In this paper, we propose the deep neural network, which restore natural images from images degraded in several ways such as noise, blur and JPEG compression in situations where the distortion applied to images is not recognized. We adopt the channel attention modules and skip connections in the proposed method, which makes the network focus on valuable information to image restoration. The proposed method is simpler to train than other methods, and experimental results show that the proposed method outperforms existing state-of-the-art methods.