• Title/Summary/Keyword: temporal feature

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Video Object Segmentation with Weakly Temporal Information

  • Zhang, Yikun;Yao, Rui;Jiang, Qingnan;Zhang, Changbin;Wang, Shi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.3
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    • pp.1434-1449
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    • 2019
  • Video object segmentation is a significant task in computer vision, but its performance is not very satisfactory. A method of video object segmentation using weakly temporal information is presented in this paper. Motivated by the phenomenon in reality that the motion of the object is a continuous and smooth process and the appearance of the object does not change much between adjacent frames in the video sequences, we use a feed-forward architecture with motion estimation to predict the mask of the current frame. We extend an additional mask channel for the previous frame segmentation result. The mask of the previous frame is treated as the input of the expanded channel after processing, and then we extract the temporal feature of the object and fuse it with other feature maps to generate the final mask. In addition, we introduce multi-mask guidance to improve the stability of the model. Moreover, we enhance segmentation performance by further training with the masks already obtained. Experiments show that our method achieves competitive results on DAVIS-2016 on single object segmentation compared to some state-of-the-art algorithms.

Semi-fragile Watermarking Scheme for H.264/AVC Video Content Authentication Based on Manifold Feature

  • Ling, Chen;Ur-Rehman, Obaid;Zhang, Wenjun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.12
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    • pp.4568-4587
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    • 2014
  • Authentication of videos and images based on the content is becoming an important problem in information security. Unfortunately, previous studies lack the consideration of Kerckhoffs's principle in order to achieve this (i.e., a cryptosystem should be secure even if everything about the system, except the key, is public knowledge). In this paper, a solution to the problem of finding a relationship between a frame's index and its content is proposed based on the creative utilization of a robust manifold feature. The proposed solution is based on a novel semi-fragile watermarking scheme for H.264/AVC video content authentication. At first, the input I-frame is partitioned for feature extraction and watermark embedding. This is followed by the temporal feature extraction using the Isometric Mapping algorithm. The frame index is included in the feature to produce the temporal watermark. In order to improve security, the spatial watermark will be encrypted together with the temporal watermark. Finally, the resultant watermark is embedded into the Discrete Cosine Transform coefficients in the diagonal positions. At the receiver side, after watermark extraction and decryption, temporal tampering is detected through a mismatch between the frame index extracted from the temporal watermark and the observed frame index. Next, the feature is regenerate through temporal feature regeneration, and compared with the extracted feature. It is judged through the comparison whether the extracted temporal watermark is similar to that of the original watermarked video. Additionally, for spatial authentication, the tampered areas are located via the comparison between extracted and regenerated spatial features. Experimental results show that the proposed method is sensitive to intentional malicious attacks and modifications, whereas it is robust to legitimate manipulations, such as certain level of lossy compression, channel noise, Gaussian filtering and brightness adjustment. Through a comparison between the extracted frame index and the current frame index, the temporal tempering is identified. With the proposed scheme, a solution to the Kerckhoffs's principle problem is specified.

Fast Video Detection Using Temporal Similarity Extraction of Successive Spatial Features (연속하는 공간적 특징의 시간적 유사성 검출을 이용한 고속 동영상 검색)

  • Cho, A-Young;Yang, Won-Keun;Cho, Ju-Hee;Lim, Ye-Eun;Jeong, Dong-Seok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.11C
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    • pp.929-939
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    • 2010
  • The growth of multimedia technology forces the development of video detection for large database management and illegal copy detection. To meet this demand, this paper proposes a fast video detection method to apply to a large database. The fast video detection algorithm uses spatial features using the gray value distribution from frames and temporal features using the temporal similarity map. We form the video signature using the extracted spatial feature and temporal feature, and carry out a stepwise matching method. The performance was evaluated by accuracy, extraction and matching time, and signature size using the original videos and their modified versions such as brightness change, lossy compression, text/logo overlay. We show empirical parameter selection and the experimental results for the simple matching method using only spatial feature and compare the results with existing algorithms. According to the experimental results, the proposed method has good performance in accuracy, processing time, and signature size. Therefore, the proposed fast detection algorithm is suitable for video detection with the large database.

A New Covert Visual Attention System by Object-based Spatiotemporal Cues and Their Dynamic Fusioned Saliency Map (객체기반의 시공간 단서와 이들의 동적결합 된돌출맵에 의한 상향식 인공시각주의 시스템)

  • Cheoi, Kyungjoo
    • Journal of Korea Multimedia Society
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    • v.18 no.4
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    • pp.460-472
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    • 2015
  • Most of previous visual attention system finds attention regions based on saliency map which is combined by multiple extracted features. The differences of these systems are in the methods of feature extraction and combination. This paper presents a new system which has an improvement in feature extraction method of color and motion, and in weight decision method of spatial and temporal features. Our system dynamically extracts one color which has the strongest response among two opponent colors, and detects the moving objects not moving pixels. As a combination method of spatial and temporal feature, the proposed system sets the weight dynamically by each features' relative activities. Comparative results show that our suggested feature extraction and integration method improved the detection rate of attention region.

A new approach for content-based video retrieval

  • Kim, Nac-Woo;Lee, Byung-Tak;Koh, Jai-Sang;Song, Ho-Young
    • International Journal of Contents
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    • v.4 no.2
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    • pp.24-28
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    • 2008
  • In this paper, we propose a new approach for content-based video retrieval using non-parametric based motion classification in the shot-based video indexing structure. Our system proposed in this paper has supported the real-time video retrieval using spatio-temporal feature comparison by measuring the similarity between visual features and between motion features, respectively, after extracting representative frame and non-parametric motion information from shot-based video clips segmented by scene change detection method. The extraction of non-parametric based motion features, after the normalized motion vectors are created from an MPEG-compressed stream, is effectively fulfilled by discretizing each normalized motion vector into various angle bins, and by considering the mean, variance, and direction of motion vectors in these bins. To obtain visual feature in representative frame, we use the edge-based spatial descriptor. Experimental results show that our approach is superior to conventional methods with regard to the performance for video indexing and retrieval.

Weighting Method based on Motion Information for Objective Video Quality Assessment (객관적 영상 화질 평가 기준를 위한 움직임 정보에 따른 중요도 결정 기법)

  • Park, Su-Young;Kim, Tae-Wan;Lee, Sang-Hoon
    • Proceedings of the IEEK Conference
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    • pp.909-910
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    • 2008
  • For evaluating the performance of some codecs, many researchers have study and develop new objective video quality assessments. However, it's not sufficient for evaluating the temporal feature of video data yet, which is a distinguishable and representative characteristic when compared with other multimedia. This paper propose the method to apply the weight to SSIM (Structural SIMilarity) according to the cognitive psychological feature. And, we presented that the performance of objective video quality assessment applied the weight to SSIM by using the proposed method is superior to one of original SSIM.

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Human Activities Recognition Based on Skeleton Information via Sparse Representation

  • Liu, Suolan;Kong, Lizhi;Wang, Hongyuan
    • Journal of Computing Science and Engineering
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    • v.12 no.1
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    • pp.1-11
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    • 2018
  • Human activities recognition is a challenging task due to its complexity of human movements and the variety performed by different subjects for the same action. This paper presents a recognition algorithm by using skeleton information generated from depth maps. Concatenating motion features and temporal constraint feature produces feature vector. Reducing dictionary scale proposes an improved fast classifier based on sparse representation. The developed method is shown to be effective by recognizing different activities on the UTD-MHAD dataset. Comparison results indicate superior performance of our method over some existing methods.

Cluster Headache-like Facial Pain following Dental Extraction: A Case Report

  • Byun, Jin-Seok;Jung, Jae-Kwang;Choi, Jae-Kap
    • Journal of Oral Medicine and Pain
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    • v.39 no.3
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    • pp.115-118
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    • 2014
  • A 50-year-old female patient with severe unilateral pain in the right eye, head, and face accompanied by lacrimation and drooping of the right eye and rhinorrhea from the right nose, which developed immediately after extraction of the maxillary right first and second molars, was successfully treated with oral administration of sumatriptan and prednisolone, or verapamile. Although the clinical characteristics are similar to those reported in cluster headache except the temporal feature, the probable cluster headache, the hemicrania continua and the acute migraine headache should be included in the list of differential diagnoses.

Temporal Characteristics Shown in Zaha Hadid's Early Architectures - Focusing on the Effect of Malevich Paintings - (자하 하디드의 초기 건축디자인에 표현된 시간적 특성 - 말레비치 회화의 영향을 중심으로 -)

  • Moon, Jung-Pil
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.30 no.8
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    • pp.153-162
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    • 2014
  • The study brought temporality that examined Malevich's pictoriality to the expression of Hadid's architecture design, aiming to examine deconstructive tendency through temporal feature that achieved interpretation of architectural form and space. The following tendencies were drawn as a spatiotemporal feature represented in Hadid's architectural design with Malevich's pictoriality in the background. First, it was found that the fragmented iconography in Hadid's illustrations was influenced by Malevich paintings, and the underlying cubist and futurist temporality was added to three-dimensional space, which was expressed as explosiveness. Second, the icons in Hadid's illustrations showed liveliness that grows in the existing architecture in order to bring images out of dynamic and connotative space, and temporality with playfulness as its medium in order to awaken space routines present in a phenomenon. Third, Hadid's illustrations made multiple simultaneous arrangements for vanishing points of multi-point and one point perspectives and combined the building site with surroundings by overlapping individual projections of plane, elevation and cross-section to represent infinity of time. Therefore, the characteristic of Hadid's architectural illustration is understood as a deconstructive text that reveals space and time to perceptual systems to embrace complex and diverse thinking that modern architecture requires.

Analysis of forest types and stand structures over Korean peninsula Using NOAA/AVHRR data

  • Lee, Seung-Ho;Kim, Cheol-Min;Oh, Dong-Ha
    • Proceedings of the KSRS Conference
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    • pp.386-389
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    • 1999
  • In this study, visible and near infrared channels of NOAA/AVHRR data were used to classify land use and vegetation types over Korean peninsula. Analyzing forest stand structures and prediction of forest productivity using satellite data were also reviewed. Land use and land cover classification was made by unsupervised clustering methods. After monthly Normalized Difference Vegetation Index (NDVI) composite images were derived from April to November 1998, the derived composite images were used as temporal feature vector's in this clustering analysis. Visually interpreted, the classification result was satisfactory in overall for it matched well with the general land cover patterns. But subclassification of forests into coniferous, deciduous, and mixed forests were much confused due to the effects of low ground resolution of AVHRR data and without defined classification scheme. To investigate into the forest stand structures, digital forest type maps were used as an ancillary data. Forest type maps, which were compiled and digitalized by Forestry Research Institute, were registered to AVHRR image coordinates. Two data sets were compared and percent forest cover over whole region was estimated by multiple regression analysis. Using this method, other forest stand structure characteristics within the primary data pixels are expected to be extracted and estimated.

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