Reversible data hiding(RDH)enables secret data embedding while preserving complete cover image recovery,making it crucial for applications requiring image integrity.The pixel value ordering(PVO)technique used in multi...Reversible data hiding(RDH)enables secret data embedding while preserving complete cover image recovery,making it crucial for applications requiring image integrity.The pixel value ordering(PVO)technique used in multi-stego images provides good image quality but often results in low embedding capability.To address these challenges,this paper proposes a high-capacity RDH scheme based on PVO that generates three stego images from a single cover image.The cover image is partitioned into non-overlapping blocks with pixels sorted in ascending order.Four secret bits are embedded into each block’s maximum pixel value,while three additional bits are embedded into the second-largest value when the pixel difference exceeds a predefined threshold.A similar embedding strategy is also applied to the minimum side of the block,including the second-smallest pixel value.This design enables each block to embed up to 14 bits of secret data.Experimental results demonstrate that the proposed method achieves significantly higher embedding capacity and improved visual quality compared to existing triple-stego RDH approaches,advancing the field of reversible steganography.展开更多
Objectives To assess the relationship between peak oxygen consumption （PVO2） and the ambulation distance in six-minute walk test （6MWT）among the healthy subjects. Methods The 51 healthy subjects were recruited for...Objectives To assess the relationship between peak oxygen consumption （PVO2） and the ambulation distance in six-minute walk test （6MWT）among the healthy subjects. Methods The 51 healthy subjects were recruited for the six-minute walk test. Data of pulmonary gas exchange breath by breath, such as VO2 , VCO2 were real-time measured with wireless remote sensing K4B2, so to study the relationship between peak oxygen uptake and the ambulation distance. Results It was noticed that there was a positive linear correlation between the ambulation distance and PVO2 （ r =0. 619, P 〈0. 001 ） in six-minute walk test. The regression equation was set up （ VO2/kg =0. 05D -6. 331, P 〈 0. 001 ）. PVO2 〉 PVCO2 ,R 〈 1 were found,which suggested that 6MWT was a test below anaerobic threshold. Conclusions There was a closely positive linear correlation between the ambulation distance and PVO2, which is safety, convenient and valuable for the evaluation of cardiopulmonary function and the treatment of cardiopulmonary rehabilitation.展开更多
针对嵌入秘密后灰度图失真明显的问题,提出一种基于像素值排序(PVO)的可逆信息隐藏算法。首先,将像素分成灰、白两层,选择灰层的像素作为目标像素,对目标像素十字交叉位置上的4个白色像素进行排序;然后根据排序结果计算两端两个像素的...针对嵌入秘密后灰度图失真明显的问题,提出一种基于像素值排序(PVO)的可逆信息隐藏算法。首先,将像素分成灰、白两层,选择灰层的像素作为目标像素,对目标像素十字交叉位置上的4个白色像素进行排序;然后根据排序结果计算两端两个像素的均值和中间两个像素的均值,利用可逆约束实现像素的动态预测;最后,根据预测结果构造预测误差直方图(PEH),使用环形复杂度实现秘密数据的自适应嵌入,并用同样的方法处理白色层像素。利用USC-SIPI标准图像库中6幅图像进行仿真实验,当嵌入容量(EC)为10 000 b,平均峰值信噪比(PSNR)为61.89 d B时,该算法能有效减小携密图像的失真。展开更多
基金funded by University of Transport and Communications(UTC)under grant number T2025-CN-004.
文摘Reversible data hiding(RDH)enables secret data embedding while preserving complete cover image recovery,making it crucial for applications requiring image integrity.The pixel value ordering(PVO)technique used in multi-stego images provides good image quality but often results in low embedding capability.To address these challenges,this paper proposes a high-capacity RDH scheme based on PVO that generates three stego images from a single cover image.The cover image is partitioned into non-overlapping blocks with pixels sorted in ascending order.Four secret bits are embedded into each block’s maximum pixel value,while three additional bits are embedded into the second-largest value when the pixel difference exceeds a predefined threshold.A similar embedding strategy is also applied to the minimum side of the block,including the second-smallest pixel value.This design enables each block to embed up to 14 bits of secret data.Experimental results demonstrate that the proposed method achieves significantly higher embedding capacity and improved visual quality compared to existing triple-stego RDH approaches,advancing the field of reversible steganography.
文摘Objectives To assess the relationship between peak oxygen consumption （PVO2） and the ambulation distance in six-minute walk test （6MWT）among the healthy subjects. Methods The 51 healthy subjects were recruited for the six-minute walk test. Data of pulmonary gas exchange breath by breath, such as VO2 , VCO2 were real-time measured with wireless remote sensing K4B2, so to study the relationship between peak oxygen uptake and the ambulation distance. Results It was noticed that there was a positive linear correlation between the ambulation distance and PVO2 （ r =0. 619, P 〈0. 001 ） in six-minute walk test. The regression equation was set up （ VO2/kg =0. 05D -6. 331, P 〈 0. 001 ）. PVO2 〉 PVCO2 ,R 〈 1 were found,which suggested that 6MWT was a test below anaerobic threshold. Conclusions There was a closely positive linear correlation between the ambulation distance and PVO2, which is safety, convenient and valuable for the evaluation of cardiopulmonary function and the treatment of cardiopulmonary rehabilitation.
文摘针对嵌入秘密后灰度图失真明显的问题,提出一种基于像素值排序(PVO)的可逆信息隐藏算法。首先,将像素分成灰、白两层,选择灰层的像素作为目标像素,对目标像素十字交叉位置上的4个白色像素进行排序;然后根据排序结果计算两端两个像素的均值和中间两个像素的均值,利用可逆约束实现像素的动态预测;最后,根据预测结果构造预测误差直方图(PEH),使用环形复杂度实现秘密数据的自适应嵌入,并用同样的方法处理白色层像素。利用USC-SIPI标准图像库中6幅图像进行仿真实验,当嵌入容量(EC)为10 000 b,平均峰值信噪比(PSNR)为61.89 d B时,该算法能有效减小携密图像的失真。
