• Journal of Korea Multimedia Society
• /
• v.24 no.4
• /
• pp.538-549
• /
• 2021

In this paper, we introduce a technique for 360-degree panoramic video streaming with multiple virtual cameras in real-time. The proposed technique consists of generating 360-degree panoramic video data by ORB feature point detection, texture transformation, panoramic video data compression, and RTSP-based video streaming transmission. Especially, the generating process of 360-degree panoramic video data and texture transformation are accelerated by CUDA for complex processing such as camera calibration, stitching, blending, encoding. Our experiment evaluated the frames per second (fps) of the transmitted 360-degree panoramic video. Experimental results verified that our technique takes at least 30fps at 4K output resolution, which indicates that it can both generates and transmits 360-degree panoramic video data in real time.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.3
• /
• pp.1121-1139
• /
• 2015

In texture-plus-depth format, depth map compression is an important task. Different from normal texture images, depth maps have less texture information, while contain many homogeneous regions separated by sharp edges. This feature will be employed to form an efficient depth map coding scheme in this paper. Firstly, the histogram of the depth map will be analyzed to find an appropriate threshold that segments the depth map into the foreground and background regions, allowing the edge between these two kinds of regions to be obtained. Secondly, the two regions will be encoded through rate distortion optimization with a shape adaptive wavelet transform, while the edges are lossless encoded with JBIG2. Finally, a depth-updating algorithm based on the threshold and the depth range is applied to enhance the quality of the decoded depth maps. Experimental results demonstrate the effective performance on both the depth map quality and the synthesized view quality.

• Journal of Korea Game Society
• /
• v.19 no.6
• /
• pp.91-98
• /
• 2019

This study verified the memory occupancy, CPU processing speed, and average frame comparison of texture formats of ASTC and ETC in mobile Android OS. The virtual game scene was implemented as an experimental environment and built on the Android platform. Based on this, comparative verification data was extracted. ASTC has a 36% lower share of memory usage of 2D textures than ETC. CPU processing speed was 18% faster. The average frame confirmed 54 frames that was 58% higher. In the smart mobile game environment, ASTC confirmed the result of comparative advantage over ETC.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.31B no.2
• /
• pp.45-55
• /
• 1994

In this paper, a block based image approximation technique using the Self Affine System(SAS) from the fractal theory is suggested. Each block of an image is divided into 4 tiles and 4 affine mapping coefficients are found for each tile. To find the affine mapping cefficients that minimize the error between the affine transformed image block and the reconstructed image block, the matrix euation is solved by setting each partial differential coefficients to aero. And to ensure the convergence of coding block. 4 uniformly partitioned affine transformation is applied. Variable block size technique is employed in order to applynatural image reconstruction property of fractal image coding. Large blocks are used for encoding smooth backgrounds to yield high compression efficiency and texture and edge blocks are divided into smaller blocks to preserve the block detail. Affine mapping coefficinets are found for each block having 16$\times$16, 8$\times$8 or 4$\times$4 size. Each block is classified as shade, texture or edge. Average gray level is transmitted for shade bolcks, and coefficients are found for texture and edge blocks. Coefficients are quantized and only 16 bytes per block are transmitted. Using the proposed algorithm, the computational load increases linearly in proportion to image size. PSNR of 31.58dB is obtained as the result using 512$\times$512, 8 bits per pixel Lena image.

• Applied Microscopy
• /
• v.44 no.1
• /
• pp.34-39
• /
• 2014

Electron backscatter diffraction (EBSD) is widely used for quantitative microstructural analysis of the crystallographic nature of variety of materials such as metals, minerals, and ceramics. EBSD can provide a wide range of information on materials including grain size, grain orientation, texture, and phase identity. In the case of metallic alloys, EBSD now has become an essential technique to analyze the texture, particularly when severe deformation is applied to the alloys. In addition, EBSD can be one of the very useful tools in identification of twin, particularly in Mg alloys. In Mg alloys different type of twin can occur depending on the c/a ratio and stacking fault energy on the twinning plane. Such an occurrence of different type of twin can be most effectively analyzed using EBSD technique. In this article, the recent development of Mg alloys and occurrence of twin in Mg are reviewed. Then, recently published example for identification of tension and compression twins in AZ31 and ZX31 is introduced to explain how EBSD can be used for identification of twin in Mg.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.31 no.6
• /
• pp.1171-1179
• /
• 2021

Image forensic is performed to check image limpidness. In this paper, a robust scheme is discussed to detect median filtering in low quality images. Detection of median filtering assists in overall image forensic. Improved spatial statistical features are extracted from the image to classify pristine and median filtered images. Image array data is rescaled to enhance the spatial statistical information. Features are extracted using Markov model on enhanced spatial statistics. Multiple difference arrays are considered in different directions for robust feature set. Further, texture operator features are combined to increase the detection accuracy and SVM binary classifier is applied to train the classification model. Experimental results are promising for images of low quality JPEG compression.

• Transactions of Materials Processing
• /
• v.33 no.5
• /
• pp.363-370
• /
• 2024

This study investigated the evolution behavior of microtexture developed in Ta-10W alloy during cold rolling. The changes in microtexture during the cold rolling process were experimentally analyzed using EBSD techniques. At relatively low rolling reductions (20%, 40%), θ-fiber and α-fiber textures were developed. However, as the reduction increased to 60% and 80%, strong α-fiber and γ-fiber textures were observed. The microtexture behavior was theoretically predicted using the VPSC polycrystal model under plane strain compression(PSC) and conditions considering deformation in the transverse direction. The VPSC model results under PSC predicted the strong development of θ-fiber texture at low reductions (20%, 40%) and the development of α-fiber and γ-fiber textures as the reduction increased to 60% and 80%. The VPSC model considering transverse deformation predicted results similar to the plane strain PSC at low reductions (20%, 40%), but as the reduction increased to 60% and 80%, it predicted that the development of α-fiber texture would be relatively weak, and the θ-fiber texture would still remain even at an 80% reduction. It was confirmed that the VPSC model considering transverse deformation more accurately predicts the evolution behavior of microtexture observed experimentally.

• Journal of the Korea Computer Industry Society
• /
• v.2 no.11
• /
• pp.1465-1476
• /
• 2001

For the applications like video indexing, text understanding, and automatic captions localization system, real-time localization of captions is an essential task. This paper presents a algorithm for localization of captions in MPEG compression images based on I frame. In this algorithm, caption text regions are segmented from background images using their distinguishing texture characteristics and chrominance information. Unlike previously published algorithms which fully decompress the video sequence before extracting the text regions, this algorithm locates candidate caption text region directly in the DCT compressed domain.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.11 no.4
• /
• pp.235-241
• /
• 2016

Compared to the former H.264 standard, the number of the prediction modes has highly increased in HEVC intra prediction. Compression efficiency and accurate prediction are significantly improved. However, the computational complexity increases as well. To solve this problem, this paper proposes the new scheme where not only prediction modes but also block partition candidate are early chosen. Compared to the original intra prediction in HEVC, the proposed scheme achieves about 38% reduction in processing cycles with a marginal loss in compression efficiency.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.3
• /
• pp.616-621
• /
• 2005

In this paper. digital watermarking algorithm based on human visual system and transform domain is presented. Firstly, original image is separated into RGB thannels, watermark is embedded into the coefficients of DCT so as to consider a contrast sensitivity and texture degrees. In preprocessing, DCT domain based transform is involved and binary image of visually recognizable patterns is utilized as a watermark. Consequently, experimental results showed that proposed algorithm is robust and imperceptibility such destruction attack as JPEG compression.