视频放大技术给予了人们观察并研究事物微小变化的机会. 利用复可控金字塔分解视频, 通过分析不同尺度不同方向的相位差来操纵视频中的运动. 复可控金字塔中某些尺度的信号放大后超出了其相移极限, 产生伪影及模糊. 调整各尺度的放大因子能够解决这一问题. 本文提出一种基于多尺度滤波的视频放大算法, 通过建立视频帧图像空间波长与振动位移的联系, 确定各尺度的放大因子的上限, 无需人工设定截止波长, 自行调整复可控金字塔各尺度的放大因子, 使得放大后的信号能够适应其相移极限. 通过对附加在大运动上的振动进行放大, 验证了本算法的性能, 相比现有的视频放大算法具有明显优势.
The video magnification technology gives people an opportunity to observe and study small changes in things. A video is decomposed by the complex steerable pyramid and the motion in the video is manipulated by analyzing the phase differences at different scales and in different directions. Magnified signals at some scales in the complex steerable pyramid exceed their phase shift limits, resulting in artifacts and blurring. This problem can be solved by adjusting the magnification factor for each scale. In this paper, a video magnification algorithm based on multi-scale filtering is proposed. A relation between the spatial wavelength of a video frame image and vibration displacement is established to determine the upper limit of the magnification factor for each scale. The manual setting of a cut-off wavelength is no longer necessary, and the amplification factor for each scale in the complex steerable pyramid is adjusted automatically so that magnified signals can adapt to their phase shift limits. The vibration attached to the large motion is magnified to verify the performance of the proposed algorithm, and the result shows that it has obvious advantages over the existing video amplification algorithms.