基于Photoshop消失点功能测量画面中目标人物身高的实验研究

Experimental Research on Measuring the Height of the Target Person in Image by Using Photoshop’s Vanishing Point Filter

基于Photoshop中消失点功能对视频监控中目标人物的身高特征进行快速准确测算,可以为公安机关破案提供侦查线索。首先针对不同情形的视频监控失真退化画面提供基于Photoshop与MATLAB的预处理方案,使图像质量达到能够有效测量的标准;然后分别利用透视作图法与消失点测量法对视频监控画面中与参照物不在同一平面上的目标人物身高进行测量;最后,分析比较两种方法的测量结果并分析误差的原因。结果显示,利用消失点测量法算得的身高与实际身高的误差小于1cm,而透视作图法算的误差在0~5cm。相较于透视作图法,消失点测量法操作简单,准确率高,适用的场合多,能为公安机关的侦查破案起到良好的辅助作用。

The purpose of research is to calculate the height of target persons quickly and accurately in the image of video surveillance by using Photoshop’s vanishing point filter in order to find clues for police agencies in the investigation. The Photoshop and MATLAB-based pre-processing methods are firstly used to correct the distorted and degraded images of the video surveillance, so that the quality of the images can reach the standard of effective measurement. Then, the perspective mapping and the vanishing point filter are respectively applied to measure the height of target persons in different dimensions of the reference objects. Finally, the results by above two measurements are to be compared and the errors be analyzed. Compared to the real height, the error calculated by the vanishing point filter is less than 1 cm, while by the perspective mapping 0~5 cm. It can be concluded that the measurement by vanishing point filter is more convenient, accurate and applicable than that by perspective mapping, which is an auxiliary to police investigation.