Jongnam Kim - Academia.edu (original) (raw)

Papers by Jongnam Kim

Applied Sciences

Three-dimensional film images which are recently developed are seen as three-dimensional using th... more Three-dimensional film images which are recently developed are seen as three-dimensional using the angle, amount, and viewing position of incident light rays. However, if the pixel contrast of the image is low or the patterns are cloudy, it does not look three-dimensional, and it is difficult to perform a quality inspection because its detection is not easy. In addition, the inspection method has not yet been developed since it is a recently developed product. To solve this problem, we propose a method to calculate the width of pixels for a specific height from the image histogram of a 3D film image and classify it based on a threshold. The proposed algorithm uses the feature that the widths of pixels by height in the image histogram of the good 3D film image are wider than the image histogram of the bad 3D film image. In the experiment, it was confirmed that the position of the height section of the image histogram has the highest classification accuracy. Through comparison tests w...

Journal of Imaging Science and Technology, 2022

The procedures of white points detection and localization are practically complex on noisy images... more The procedures of white points detection and localization are practically complex on noisy images. In this paper, we propose an algorithm that detects and localizes white points on 3D film images. The proposed algorithm uses the fast Fourier transform to convert the binarized image into real and imaginary parts to obtain the number of white points along the horizontal and vertical. We determine the sorted coordinates of the white points by adding a brute-force solution to the coordinates obtained from the real part of the image. These sorted coordinates are obtained by subtracting the error between the Euclidean distances of the normalized coordinates along the vertical and horizontal direction. The proposed algorithm with and without brute-force achieved an average detection ratio of 0.98 and 0.88 respectively, while the others underperformed. We perform various experiments using the existing algorithms such as template matching, thresholding, and an iterative method to validate th...

ISCAS'99. Proceedings of the 1999 IEEE International Symposium on Circuits and Systems VLSI (Cat. No.99CH36349)

In the fields of low bit rate coding and real time video coding, the three-step search (TSS) algo... more In the fields of low bit rate coding and real time video coding, the three-step search (TSS) algorithm for fast motion estimation has played a key role because of its regularity, reasonable performance, and reduced amount of computation for searching the motion vector. In this work, a new fast TSS algorithm is proposed, which is based on UESA, half-stop method in matching pursuit and gradient-assisted adaptive matching scan for fast motion estimation. The first approach efficiently reduces checking points in the search range with reasonable PSNR performance. Two other algorithms remove unnecessary computations in obtaining the matching error without any degradation of error performance. This work is useful in the applications of software-based real-time video coding and low bit rate video coding.

When applying PDE algorithm according to the complexity of the image, the problem is how to get c... more When applying PDE algorithm according to the complexity of the image, the problem is how to get complexity of the image. J.N. Kim and et al. proposed one method, which results in significant reduced computation with the same predicted image quality of the conventional FS [1]. But by localizing the image well, we can get more the reduction of unnecessary computation. In general, image complexity is localized in pieces rather than the whole span of image or some fixed blocks. If we use localization with small subblocks, the PDE algorithm can be represented as shown in Eq. (1). Generally, image complexity is distributed sparsely in small patches rather than globally in whole image. From the viewpoint, we can well classify image complexity by small subblock unit rather than by whole row vector or column one of matching blocks. It is very important in Eq. (1) to detect the image area with larger matching error. That is, by first checking more complex area of matching block, we can get la...

The transition to digital in the TV broadcasting industry is already gradually being performed wh... more The transition to digital in the TV broadcasting industry is already gradually being performed while the complete digital switchover seems now possible to be accomplished within the near future. This article describes and analyses this phenomenon and the role of MPEG-21 may play in it. MPEG-21 is the ISO/IEC standard currently under development in MPEG (ISO/IEC JTC1/SC29/WG11). Unlike preceding MPEG standards MPEG-21 does not specify a coding format of the content but rather a set of standards to ease transactions of multimedia content and the provision of digital multimedia services in heterogeneous network environments, including broadcast. In this paper, we highlight the role of MPEG-21 in broadcasting, in particular in the deployment of digital TV services.

Estimation of 3-D objects from 2-D images is inherently performed by either motion or scene featu... more Estimation of 3-D objects from 2-D images is inherently performed by either motion or scene features methods as it has been described in different literatures. Structure from motion as a method employed in this study uses calibrated camera and reconstructed 3-D points from the structure of the scene for reliable and precise estimates. In this study we construct 3-D shapes using color pixels and reconstructed 3-D points to determine observable differences for the constructed 3-D images. The estimation using reconstructed 3-D points indicates that the sphere is recovered by the use of scale factor due to its known size while the one obtained by using color pixels has look similar to the former but different in the scales of the axes.

Communications in Computer and Information Science

Abstract. In this paper, we propose a real-time video watermarking chip and system which is hardw... more Abstract. In this paper, we propose a real-time video watermarking chip and system which is hardware based watermark embedding system of SD/HD (standard definition/high definition) video with STRATIX FPGA device from ALTERA as well as we implement the watermark ...

Journal of Computer and Communications, 2019

Applications of Digital Image Processing XXI, 1998

The three-step search (TSS) has played a key role in real time video encoding because of its ligh... more The three-step search (TSS) has played a key role in real time video encoding because of its light computational complexity, regularity of search rule, and reasonable performance for reduced computation. Many researches about modified TSS algorithms have been studied for reducing the amount of computation or improving the quality of the image predicted with obtained motion vector. This paper explains a new concept of hierarchical search in motion estimation for more reduction of computational complexity and better error performance compared with conventional modified TSS algorithms. The structure of the proposed algorithm is similar to that of the conventional TSS algorithm. The proposed algorithm, however, has different precision of search for each step. It will be shown that the proposed algorithm is very efficient in terms of speed up for computation and has improved error performance over the conventional modified TSS algorithms. Our proposed algorithm will be useful in software-based real-time video coding and low bit rate video coding.

SPIE Proceedings, 1999

Three-step search (TSS) has been studied for low bit-rate video communications because of signifi... more Three-step search (TSS) has been studied for low bit-rate video communications because of significantly reduced computation, simplicity and reasonable performance in the motion estimation. Many other modified TSS algorithms have been developed for higher speedup of computation and improved error performance of motion compensation. Among the modified TSS algorithms, new three-step search (NTSS) shows very good error performance with more reduced computation on the average. However, the method can exceed about 30% compared with the computation of TSS for some cases. It can be serious problem in real-time video coding at the worst case. This paper proposes an efficient and adaptive three-step search (EATSS) algorithm with adaptive search strategy considering unequal subsampling and partial distortion elimination (PDE). Proposing search strategy reduces useless checking points of the first step in the NTSS by using initial sum of absolute difference (SAD) and predefined threshold of SAD. Instead of checking 17 candidate points in the first step as the NTSS, our search algorithm starts with 1 or 9 checking points according to the comparison between initial SAD and predefined threshold of SAD. Experimentally, our algorithm shows good performance in terms of PSNR of predicted images and average checking points for each block compared with NTSS and TSS.

Image and Video Communications and Processing 2000, 2000

New three-step search (NTSS) algorithm obtains good picture quality in predicted images with more... more New three-step search (NTSS) algorithm obtains good picture quality in predicted images with more reduced computation on the average. To reduce more the computation while keeping error performance compared with NTSS, this paper proposes a fast NTSS algorithm using unimodal error surface assumption correlation of causal adjacent matching errors, partial distortion elimination (PDE) algorithm and cross search algorithm. Proposing algorithm reduces less important checking points of the first step in the NTSS by using initial sum of absolute difference (SAD) and adaptive threshold of SAD. Instead of checking seventeen candidate points in the first step like the NTSS, our search algorithm starts with nine checking points according to the result of comparison between initial SAD and adaptive threshold of SAD. We get adaptive threshold of SAD according to the causal adjacent SADs. For more computational reduction without any degradation in prediction quality, we employ PDE and cross search algorithm. Therefore, we can apply this algorithm to variety of applications because the threshold is adaptive to the characteristics of each sequence. Experimentally, our algorithm shows good performance in terms of PSNR of predicted images and average-checking points for each block compared with the conventional NTSS and TSS algorithms.

Journal of Korea Multimedia Society, 2013

Journal of the Institute of Electronics and Information Engineers, 2014

With the advancement of the digital broadcasting and popularity of Internet, there is an increasi... more With the advancement of the digital broadcasting and popularity of Internet, there is an increasing demand for digital data. Recently, several studies have been made on the digital watermarking for copyright protection of digital data. We propose a blind video watermarking using minimum modification of motion vectors. Conventional methods based on motion vectors do watermarking using modification of motion vectors. However, change of motion vectors results in the degradation of video quality. Thus, our proposed algorithm minimizes modification of the original motion vectors to avoid degradation of video quality using simple embedded conditions. Besides, our scheme guarantees the amount of embedded watermark data using the adaptive threshold considering the human visual characteristic. In addition, this is compatible with current video compression standards without changing the bitstream. Experimental result shows that the proposed scheme obtains better video quality than other previous algorithms by about .

International Conference on Hybrid Information Technology, Nov 11, 2008

Shot change detection is the main technique for automatic temporal segmentation of video. Until n... more Shot change detection is the main technique for automatic temporal segmentation of video. Until now, there were little research reports about real-time shot change detection for applying to hardware terminals with low performance such as PMPs (Portable Multimedia Player) and cellular phones. In this paper, we propose an adaptive real-time shot change detection algorithm using sub-sampling, weighting variance, and an adaptive threshold. We use weighting variance of frame difference for dividing feature extraction at a changed frame. We set an adaptive threshold using the average of variance from the next one of a last shot change frame to the previous one of a current frame. In the experiments, we obtained the detection rate of about 94.4% in overall accuracy. We verified real-time operation of shot change detection by implementing our algorithm on the TVUS HM-900 PMP from the company of Homecast. Therefore, our proposing algorithm will be helpful in searching video data on portable media player such as PMPs and cellular phones.

2009 11th International Conference on Advanced Communication Technology, Feb 15, 2009

in this paper, we propose a real-time encryption method without additional information in digital... more in this paper, we propose a real-time encryption method without additional information in digital multimedia broadcasting (DMB) contents using AES (advanced encryption standard) encryption algorithm and implement it on a personal multimedia player (PMP). As the experimental result, we examined the operation of real time encryption and decryption in PMP with format compliance, while without increment of file size. Additionally, we confirmed that the saved contents in a PMP were not played in other devices without decryption key. Our implemented system can be useful in real-time applications requiring contents protection service such as video on demand, IPTV and digital TV.

At July 2008, the nationwide DMB (Digital Multimedia Broadcasting) has got started. As DMB device... more At July 2008, the nationwide DMB (Digital Multimedia Broadcasting) has got started. As DMB device's volume of sales has been over 12 million already, the development of rapidly changing network systems has increased the dangers of infringing the copyright of DMB contents. For solving this problem, we suggest that real-time encryption algorithm without additional expenses, and implemented that on PMP. We used the SEED algorithm for encryption. As the experimental result, we confirmed that the real-time encryption and decryption of DMB videos were working well. Also confirmed that recorded contents in PMP were not replayed in other devices, and also the contents recorded by other devices were not played in PMP. Suggested algorithms can be useful in the VOD, IPTV or cable TV.

In this paper, we propose a fast motion estimation algorithm for video encoding. Conventional fas... more In this paper, we propose a fast motion estimation algorithm for video encoding. Conventional fast motion estimation algorithms have a serious problem of low prediction quality in some frames. However, full search based fast algorithms have low computational reduction ratio. In the paper, we propose an algorithm that significantly reduces unnecessary computations, while keeping prediction quality almost similar to that of the full search. The proposed algorithm uses distribution probability of motion vectors and adaptive search patterns and block matching criteria. By taking different search patterns and error criteria of block matching according to distribution probability of motion vectors, we can reduces only unnecessary computations efficiently. Our algorithm takes only 20~30% in computational amount and has decreased prediction quality about 0~0.02dB compared with the fast full search of the H.264 reference software. Our algorithm will be useful to real-time video coding applications using MPEG-2 or MPEG-4 AVC standards.

Proceedings of the 11th International Conference on Advanced Communication Technology Volume 3, Feb 15, 2009

CAS is positively necessary to streaming service such as IPTV and VOD, charging cable TV broadcas... more CAS is positively necessary to streaming service such as IPTV and VOD, charging cable TV broadcasting channels, charging satellite broadcasting channels and so on . CAS system must show clean images to authorized users and have unauthorized users unable to enjoy the images normally. To make these environments, algorism that costs less additional expenses is needed, encryption is suggested as the method. In this paper, optional encryption of H.264 image was implemented for authorization system. Suggested method is to transcode the contents of various formats, convert into YUV format, compress it using H.264 codec and encrypt the particular part following needs. By the experiment, unauthorized users without encryption key cannot see the images properly, and that when make the intensity of encryption high, playing was possible but recognition of the images was not possible is recognizable. Also, encrypting the image of 300 frames took 71.3 seconds on the average, so being very fast is recognizable, too. Suggested contents are usable to the areas of user authorization and copyright protection in streaming service such as IPTV and VOD.