为了解决空间遥感凝视型探测器获取的数据量巨大的问题,研究了红外图像的无损压缩。经比较,JPEG2000国际标准压缩算法具有较好的压缩性能且有相应的ASIC(Application Specific Integrated Circuit)芯片易于系统实现。本文对连续的红外...为了解决空间遥感凝视型探测器获取的数据量巨大的问题,研究了红外图像的无损压缩。经比较,JPEG2000国际标准压缩算法具有较好的压缩性能且有相应的ASIC(Application Specific Integrated Circuit)芯片易于系统实现。本文对连续的红外图像序列的空间和时间相关性进行了分析,以此为基础提出了一种基于预测和JPEG2000算法相结合的无损压缩方案,并以ASIC和FPGA为平台实现了一个复杂度低、性能高的实时无损压缩系统。对不同复杂程度的源图像进行的压缩实验表明,该系统能够实现连续红外图像平均无损压缩比4.516,与JPEG2000标准算法相比,无损压缩比提高了59%以上。展开更多
视频压缩可以减小视频的大小以提高传输效率,但压缩过程中会造成一定程度上的失真和噪声。目前主流的多帧质量增强模型在方法上过于单一,仅使用前后峰值帧或相邻帧进行简单增强,缺乏灵活性。基于上述问题,提出了一种基于帧间相关性的动...视频压缩可以减小视频的大小以提高传输效率,但压缩过程中会造成一定程度上的失真和噪声。目前主流的多帧质量增强模型在方法上过于单一,仅使用前后峰值帧或相邻帧进行简单增强,缺乏灵活性。基于上述问题,提出了一种基于帧间相关性的动态多帧质量增强(DMFQE)方法。该方法是采用了两步增强策略,首先,将待增强帧分别输入所设计的光流补偿网络和帧预测网络进行质量增强;然后,将得到的光流增强帧和预测增强帧进行卷积后输入图像重构模块进行重构,获得最终增强帧。实验结果表明:在每一帧上,DMFQE比HEVC/H.265平均多获得0.36 dB PSNR增益;在LDP的编码模式下,DMFQE比单一的多帧质量增强模型MFQE、MFQE2.0拥有更好的有效性。展开更多
Video shreds of evidence are usually admissible in the court of law all over the world. However, individuals manipulate these videos to either defame or incriminate innocent people. Others indulge in video tampering t...Video shreds of evidence are usually admissible in the court of law all over the world. However, individuals manipulate these videos to either defame or incriminate innocent people. Others indulge in video tampering to falsely escape the wrath of the law against misconducts. One way impostors can forge these videos is through inter-frame video forgery. Thus, the integrity of such videos is under threat. This is because these digital forgeries seriously debase the credibility of video contents as being definite records of events. <span style="font-family:Verdana;">This leads to an increasing concern about the trustworthiness of video contents. Hence, it continues to affect the social and legal system, forensic investigations, intelligence services, and security and surveillance systems as the case may be. The problem of inter-frame video forgery is increasingly spontaneous as more video-editing software continues to emerge. These video editing tools can easily manipulate videos without leaving obvious traces and these tampered videos become viral. Alarmingly, even the beginner users of these editing tools can alter the contents of digital videos in a manner that renders them practically indistinguishable from the original content by mere observations. </span><span style="font-family:Verdana;">This paper, however, leveraged on the concept of correlation coefficients to produce a more elaborate and reliable inter-frame video detection to aid forensic investigations, especially in Nigeria. The model employed the use of the idea of a threshold to efficiently distinguish forged videos from authentic videos. A benchmark and locally manipulated video datasets were used to evaluate the proposed model. Experimentally, our approach performed better than the existing methods. The overall accuracy for all the evaluation metrics such as accuracy, recall, precision and F1-score was 100%. The proposed method implemented in the MATLAB programming language has proven to effectively detect inter-frame forgeries.</span>展开更多
文摘为了解决空间遥感凝视型探测器获取的数据量巨大的问题,研究了红外图像的无损压缩。经比较,JPEG2000国际标准压缩算法具有较好的压缩性能且有相应的ASIC(Application Specific Integrated Circuit)芯片易于系统实现。本文对连续的红外图像序列的空间和时间相关性进行了分析,以此为基础提出了一种基于预测和JPEG2000算法相结合的无损压缩方案,并以ASIC和FPGA为平台实现了一个复杂度低、性能高的实时无损压缩系统。对不同复杂程度的源图像进行的压缩实验表明,该系统能够实现连续红外图像平均无损压缩比4.516,与JPEG2000标准算法相比,无损压缩比提高了59%以上。
文摘视频压缩可以减小视频的大小以提高传输效率,但压缩过程中会造成一定程度上的失真和噪声。目前主流的多帧质量增强模型在方法上过于单一,仅使用前后峰值帧或相邻帧进行简单增强,缺乏灵活性。基于上述问题,提出了一种基于帧间相关性的动态多帧质量增强(DMFQE)方法。该方法是采用了两步增强策略,首先,将待增强帧分别输入所设计的光流补偿网络和帧预测网络进行质量增强;然后,将得到的光流增强帧和预测增强帧进行卷积后输入图像重构模块进行重构,获得最终增强帧。实验结果表明:在每一帧上,DMFQE比HEVC/H.265平均多获得0.36 dB PSNR增益;在LDP的编码模式下,DMFQE比单一的多帧质量增强模型MFQE、MFQE2.0拥有更好的有效性。
文摘Video shreds of evidence are usually admissible in the court of law all over the world. However, individuals manipulate these videos to either defame or incriminate innocent people. Others indulge in video tampering to falsely escape the wrath of the law against misconducts. One way impostors can forge these videos is through inter-frame video forgery. Thus, the integrity of such videos is under threat. This is because these digital forgeries seriously debase the credibility of video contents as being definite records of events. <span style="font-family:Verdana;">This leads to an increasing concern about the trustworthiness of video contents. Hence, it continues to affect the social and legal system, forensic investigations, intelligence services, and security and surveillance systems as the case may be. The problem of inter-frame video forgery is increasingly spontaneous as more video-editing software continues to emerge. These video editing tools can easily manipulate videos without leaving obvious traces and these tampered videos become viral. Alarmingly, even the beginner users of these editing tools can alter the contents of digital videos in a manner that renders them practically indistinguishable from the original content by mere observations. </span><span style="font-family:Verdana;">This paper, however, leveraged on the concept of correlation coefficients to produce a more elaborate and reliable inter-frame video detection to aid forensic investigations, especially in Nigeria. The model employed the use of the idea of a threshold to efficiently distinguish forged videos from authentic videos. A benchmark and locally manipulated video datasets were used to evaluate the proposed model. Experimentally, our approach performed better than the existing methods. The overall accuracy for all the evaluation metrics such as accuracy, recall, precision and F1-score was 100%. The proposed method implemented in the MATLAB programming language has proven to effectively detect inter-frame forgeries.</span>
