期刊文献+
共找到8篇文章
< 1 >
每页显示 20 50 100
A HEVC Video Steganalysis Method Using the Optimality of Motion Vector Prediction
1
作者 Jun Li Minqing Zhang +2 位作者 ke niu Yingnan Zhang Xiaoyuan Yang 《Computers, Materials & Continua》 SCIE EI 2024年第5期2085-2103,共19页
Among steganalysis techniques,detection against MV(motion vector)domain-based video steganography in the HEVC(High Efficiency Video Coding)standard remains a challenging issue.For the purpose of improving the detectio... Among steganalysis techniques,detection against MV(motion vector)domain-based video steganography in the HEVC(High Efficiency Video Coding)standard remains a challenging issue.For the purpose of improving the detection performance,this paper proposes a steganalysis method that can perfectly detectMV-based steganography in HEVC.Firstly,we define the local optimality of MVP(Motion Vector Prediction)based on the technology of AMVP(Advanced Motion Vector Prediction).Secondly,we analyze that in HEVC video,message embedding either usingMVP index orMVD(Motion Vector Difference)may destroy the above optimality of MVP.And then,we define the optimal rate of MVP as a steganalysis feature.Finally,we conduct steganalysis detection experiments on two general datasets for three popular steganographymethods and compare the performance with four state-ofthe-art steganalysis methods.The experimental results demonstrate the effectiveness of the proposed feature set.Furthermore,our method stands out for its practical applicability,requiring no model training and exhibiting low computational complexity,making it a viable solution for real-world scenarios. 展开更多
关键词 Video steganography video steganalysis motion vector prediction motion vector difference advanced motion vector prediction local optimality
下载PDF
Adaptive Video Dual Domain Watermarking Scheme Based on PHT Moment and Optimized Spread Transform Dither Modulation
2
作者 Yucheng Liang ke niu +2 位作者 Yingnan Zhang Yifei Meng Fangmeng Hu 《Computers, Materials & Continua》 SCIE EI 2024年第11期2457-2492,共36页
To address the challenges of video copyright protection and ensure the perfect recovery of original video,we propose a dual-domain watermarking scheme for digital video,inspired by Robust Reversible Watermarking(RRW)t... To address the challenges of video copyright protection and ensure the perfect recovery of original video,we propose a dual-domain watermarking scheme for digital video,inspired by Robust Reversible Watermarking(RRW)technology used in digital images.Our approach introduces a parameter optimization strategy that incre-mentally adjusts scheme parameters through attack simulation fitting,allowing for adaptive tuning of experimental parameters.In this scheme,the low-frequency Polar Harmonic Transform(PHT)moment is utilized as the embedding domain for robust watermarking,enhancing stability against simulation attacks while implementing the parameter optimization strategy.Through extensive attack simulations across various digital videos,we identify the optimal low-frequency PHT moment using adaptive normalization.Subsequently,the embedding parameters for robust watermarking are adaptively adjusted to maximize robustness.To address computational efficiency and practical requirements,the unnormalized high-frequency PHT moment is selected as the embedding domain for reversible watermarking.We optimize the traditional single-stage extended transform dithering modulation(STDM)to facilitate multi-stage embedding in the dual-domain watermarking process.In practice,the video embedded with a robust watermark serves as the candidate video.This candidate video undergoes simulation according to the parameter optimization strategy to balance robustness and embedding capacity,with adaptive determination of embedding strength.The reversible watermarking is formed by combining errors and other information,utilizing recursive coding technology to ensure reversibility without attacks.Comprehensive analyses of multiple performance indicators demonstrate that our scheme exhibits strong robustness against Common Signal Processing(CSP)and Geometric Deformation(GD)attacks,outperforming other advanced video watermarking algorithms under similar conditions of invisibility,reversibility,and embedding capacity.This underscores the effectiveness and feasibility of our attack simulation fitting strategy. 展开更多
关键词 Dual-domain H.264 group of pictures polar harmonic transform spread transform dither modulation
下载PDF
A Dual Domain Robust Reversible Watermarking Algorithm for Frame Grouping Videos Using Scene Smoothness
3
作者 Yucheng Liang ke niu +1 位作者 Yingnan Zhang Yifei Meng 《Computers, Materials & Continua》 SCIE EI 2024年第6期5143-5174,共32页
The proposed robust reversible watermarking algorithm addresses the compatibility challenges between robustness and reversibility in existing video watermarking techniques by leveraging scene smoothness for frame grou... The proposed robust reversible watermarking algorithm addresses the compatibility challenges between robustness and reversibility in existing video watermarking techniques by leveraging scene smoothness for frame grouping videos.Grounded in the H.264 video coding standard,the algorithm first employs traditional robust watermark stitching technology to embed watermark information in the low-frequency coefficient domain of the U channel.Subsequently,it utilizes histogram migration techniques in the high-frequency coefficient domain of the U channel to embed auxiliary information,enabling successful watermark extraction and lossless recovery of the original video content.Experimental results demonstrate the algorithm’s strong imperceptibility,with each embedded frame in the experimental videos achieving a mean peak signal-to-noise ratio of 49.3830 dB and a mean structural similarity of 0.9996.Compared with the three comparison algorithms,the performance of the two experimental indexes is improved by 7.59%and 0.4%on average.At the same time,the proposed algorithm has strong robustness to both offline and online attacks:In the face of offline attacks,the average normalized correlation coefficient between the extracted watermark and the original watermark is 0.9989,and the average bit error rate is 0.0089.In the face of online attacks,the normalized correlation coefficient between the extracted watermark and the original watermark is 0.8840,and the mean bit error rate is 0.2269.Compared with the three comparison algorithms,the performance of the two experimental indexes is improved by 1.27%and 18.16%on average,highlighting the algorithm’s robustness.Furthermore,the algorithm exhibits low computational complexity,with the mean encoding and the mean decoding time differentials during experimental video processing being 3.934 and 2.273 s,respectively,underscoring its practical utility. 展开更多
关键词 Robust reversible watermarking scene smoothness dual-domain U channel H.264 encoding standard
下载PDF
A MV-Based Steganographic Algorithm for H.264/AVC without Distortion 被引量:1
4
作者 Hongqiong Tang Xiaoyuan Yang +1 位作者 Yingnan Zhang ke niu 《Computers, Materials & Continua》 SCIE EI 2020年第6期1205-1219,共15页
H.264/AVC video is one of the most popular multimedia and has been widely used as the carriers of video steganography.In this paper,a novel motion vector(MV)based steganographic algorithm is proposed for the H.264/AVC... H.264/AVC video is one of the most popular multimedia and has been widely used as the carriers of video steganography.In this paper,a novel motion vector(MV)based steganographic algorithm is proposed for the H.264/AVC compressed video without distortion.Four modules are introduced to eliminate the distortion caused by the modifications of motion vectors and guarantee the security of the algorithm.In the embedding block,the motion vector space encoding is used to embed a(2n+1)-ary notational number into an n-dimension vector composed of motion vectors generated from the selection block.Scrambling is adopted to disturb the order of steganographic carriers to improve the randomness of the carrier before the operation of embedding.The re-motion compensation(re-MC)block will re-construct the macroblock(MB)whose motion vectors have been modified by embedding block.System block plays the role of the generator for chaotic sequences and encryptor for secret data.Experimental results demonstrate that our proposed algorithm can achieve high embedding capacity without stego video visual quality distortion,it also presents good undetectability for existing MV-based steganalysis feature.Performance comparisons with other existing algorithms are provided to demonstrate the superiority of the proposed algorithm. 展开更多
关键词 Video steganography motion vector without distortion H.264/AVC
下载PDF
眼带状疱疹性葡萄膜炎合并前房积血1例
5
作者 牛科 吕永斌 +1 位作者 于广委 王东林 《中华眼视光学与视觉科学杂志》 CAS CSCD 北大核心 2024年第1期66-67,共2页
患者,男,74岁,因“左眼视物不见伴眼胀、眼痛3 d”于2022年1月6日就诊于济南明水眼科医院,当日上午曾就诊于当地医院眼科,诊断为“左眼新生血管性青光眼”,建议至上级医院就诊。患者于半个月前因“眼带状疱疹”在当地医院行输液治疗,具... 患者,男,74岁,因“左眼视物不见伴眼胀、眼痛3 d”于2022年1月6日就诊于济南明水眼科医院,当日上午曾就诊于当地医院眼科,诊断为“左眼新生血管性青光眼”,建议至上级医院就诊。患者于半个月前因“眼带状疱疹”在当地医院行输液治疗,具体不详。患者糖尿病病史2年,血糖控制良好。否认外伤及手术史。眼部检查:右眼最佳矫正视力(BCVA)0.6,左眼光感,光定位准;右眼眼压15 mmHg(1 mmHg=0.133 kPa),左眼35 mmHg。裂隙灯显微镜检查示:右眼晶状体混浊(+),余眼前后节未见明显异常,左眼眼睑肿胀,左侧前额、上眼睑、鼻梁及鼻尖色素沉着. 展开更多
关键词 眼带状疱疹 新生血管性青光眼 前房积血 葡萄膜炎 眼部检查 眼科医院 医院眼科 上眼睑
原文传递
A Novel Video Reversible Data Hiding Algorithm Using Motion Vector for H.264/AVC 被引量:6
6
作者 ke niu Xiaoyuan Yang Yingnan Zhang 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2017年第5期489-498,共10页
A novel reversible data hiding algorithm for H.264/AVC videos is proposed. Histogram Shifting (HS) of motion vector values is used efficiently in reversible data hiding to embed data. By designating a specific decod... A novel reversible data hiding algorithm for H.264/AVC videos is proposed. Histogram Shifting (HS) of motion vector values is used efficiently in reversible data hiding to embed data. By designating a specific decoded reference frame, the distortion accumulation effects due to modification of the motion vectors is overcome. All the extracted information can be recovered without loss of the original compressed video carrier. The experimental results show that the proposed algorithm is simple, has higher capacity and invisibility than other existing schemes, and can adjust the relationship between capacity and invisibility according to embedded load. 展开更多
关键词 reversible video data hiding H.264/AVC motion vector histogram modification modified referenceframe
原文传递
Risk Factors for Mesh Exposure after Transvaginal Mesh Surgery 被引量:4
7
作者 ke niu Yong-Xian Lu +2 位作者 Wen-Jie Shen Ying-Hui Zhang Wen-Ying Wang 《Chinese Medical Journal》 SCIE CAS CSCD 2016年第15期1795-1799,共5页
Background: Mesh exposure after surgery continues to be a clinical challenge for urogynecological surgeons. The purpose of this study was to explore the risk factors for polypropylene (PP) mesh exposure after trans... Background: Mesh exposure after surgery continues to be a clinical challenge for urogynecological surgeons. The purpose of this study was to explore the risk factors for polypropylene (PP) mesh exposure after transvaginal mesh (TVM) surgery. Methods: This study included 195 patients with advanced pelvic organ prolapse (POP), who underwent TVM from January 2004 to December 2012 at the First Affiliated Hospital of Chinese PLA General Hospital. Clinical data were evaluated including patient's demography, TVM type, concomitant procedures, operation time, blood loss, postoperative morbidity, and mesh exposure. Mesh exposure was identified through postoperative vaginal examination. Statistical analysis was performed to identify risk factors for mesh exposure. Results: Two-hundred and nine transvaginal PP meshes were placed, including 194 in the mltefior wall and 15 in the posterior wall. Concomitant tension-free vaginal tape was pertbrmed in 61 cases. The mean follow-up time was 35.1 :e 23.6 months. PP mesh exposure was identified in 32 cases (16.4%), with 31 in the anterior wall and 1 in the posterior wall. Significant difference was found in operating time and concomitant procedures between exposed and nonexposed groups (F = 7.443, P = 0.007; F = 4.307, P = 0.039, respectively). Binary logistic regression revealed that the number of concomitant procedures and operation time were risk factors for mesh exposure (P = 0.001, P = 0.043). Conclusion: Concomitant procedures and increased operating time increase the risk for postoperative mesh exposure in patients undergoing TVM surgery for POP. 展开更多
关键词 High Risk POLYPROPYLENE Transvaginal Mesh
原文传递
Nd:YAG激光后囊切开术后致黄斑裂孔性视网膜脱离1例
8
作者 牛科 王东林 《中华眼视光学与视觉科学杂志》 CAS CSCD 2022年第8期628-631,共4页
患者,女,56岁。因"右眼Nd:YAG激光后囊切开术后视物不见5 d"于2020年9月27日就诊于济南明水眼科医院。糖尿病病史17年,口服药物控制血糖,血糖控制可。因右眼玻璃体积血、糖尿病视网膜病变、年龄相关性白内障于2020年8月06日... 患者,女,56岁。因"右眼Nd:YAG激光后囊切开术后视物不见5 d"于2020年9月27日就诊于济南明水眼科医院。糖尿病病史17年,口服药物控制血糖,血糖控制可。因右眼玻璃体积血、糖尿病视网膜病变、年龄相关性白内障于2020年8月06日在济南明水眼科医院行右眼玻璃体切割+白内障摘除+人工晶状体植入术。术后3 d视力由0.02恢复至0.15,术后20 d激光扫描检眼镜可见视盘边界清楚、颜色稍淡,杯盘比约0.5,动静脉血管形态走形未见异常,视网膜呈豹纹状,全视网膜激光斑反应良好,黄斑中心凹反光未见(见图1);光学相干断层扫描(OCT)检查示:视网膜色素上皮(RPE)层和椭圆体带欠连续(见图2)。患者右眼术后1个半月复查时,诉右眼视力下降,查体见右眼视力0.05,后囊膜增厚混浊,诊断为右眼后发性白内障。于2020年8月22日门诊行右眼Nd:YAG激光后囊切开术,激光能量1.5 mJ/脉冲,爆破点数25点,后囊孔3.5 mm,术后即查视力0.15,眼压18 mmHg(1 mmHg=0.133 kPa),裂隙灯显微镜下检查示:右眼角膜透明,前房中深,房水闪辉(+),人工晶状体位正,后囊膜切开,玻璃体腔少量混浊,眼底未查。术后5 d,患者诉右眼视物不见,来济南明水眼科医院就诊。全身检查未见明显异常。 展开更多
关键词 视网膜色素上皮 眼科医院 右眼视力 人工晶状体 白内障摘除 全身检查 玻璃体积血 杯盘比
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部