红外热像视频的细微变化放大

目的 针对红外热像视频对比度低、成像模糊和难以进行细节观测的缺点,提出一种基于欧拉视角的红外热像视频细微变化放大方法。该方法可以将红外热像视频中细微的色彩变化和动作变化进行放大,将原本人眼无法察觉到的变化清晰地展示出来。方法 该方法首先采用对比度金字塔算法对红外热像视频中每一帧图像进行空域分解,其次对各个尺度的图像进行时域滤波,选择出感兴趣的变化频率并进行线性放大,然后对放大后的信号进行重构,最后对重构得到的图像进行降噪处理,从而获得细微变化放大的红外视频。结果 针对色彩放大和动作放大,实验采集了若干红外热像视频。其中,对人脸侧面的颜色进行放大时,选择像素值变化频率在0.751 Hz 范围内的信号进行滤波并放大,得到像素值变化被放大100倍的视频;对吉他弦的动作进行放大时,选择变化频率在100120 Hz范围内的信号进行滤波并放大,得到弦的动作幅度被放大的视频。结果表明该方法可以使视频中所选择的变化频段得到有效增强。结论 本文方法可以放大红外视频中原本无法观测到的细微变化,并使之清晰呈现,在军用和民用领域中有着广泛用途。

Magnifying imperceptible variations in infrared thermal videos

Objective Infrared thermal devices are widely used in the industrial, medical, military, and other fields and significantly expand the visual perception range of humans. However, infrared thermal videos have low contrast and blurred details, and the subtle variations in these videos are difficult to observe. In this work, we design an amplification method for magnifying the barely seen changes in infrared thermal videos based on Eulerian perspective. Our goal is to reveal temporal variations that are difficult or impossible to be seen with the naked eye and to display these variations in an indicative manner. Method The proposed method uses an infrared thermal video as input and applies contrast pyramid decomposition to each frame, followed by temporal filtering of the decomposed images. The signals selected by temporal filtering are then amplified to reveal hidden information. The contrast pyramid is then constructed. Finally, noise reduction is performed on the reconstructed images, and the final output is obtained. Result Corresponding infrared thermal videos were obtained, and experiments were conducted on these videos to magnify the subtle colors and motion variations. For example, the signal from 0.75 Hz to 1 Hz of a profile video was filtered and magnified 100 times as output to augment the color changes in the video. The signal from 100 Hz to 120 Hz of a guitar video was also filtered and then magnified 30 times as output to augment the motion variations in the video. Experiments showed that the proposed method can effectively magnify imperceptible variations in infrared thermal videos. Conclusion This study demonstrates that imperceptible variations in infrared thermal videos can be magnified and shown to observers in an indicative manner, which is valuable for both military and civil fields.