提出一种新颖的基于视频的降雨量测量方法。首先根据雨图亮度变化特征检测雨滴;其次,为解决雨滴离摄像机距离信息未知情况下的雨滴尺寸估计问题,在雨滴成像光度模型中融入散聚焦因素,构建了基于亮度差和色彩张量响应特征的散聚焦雨滴判别方法;然后,根据透视成像关系计算聚焦雨滴的尺寸并根据气象学雨滴谱的定义来构建观测雨滴谱;最后,为抑制观测雨滴谱中的噪声,采用气象学Gamma模型拟合观测雨滴谱,并由模型参数计算降雨量。在不同程度的降雨环境下实验检验算法,并与雨量计记录数据对比,测量结果较为一致。
Monitoring of raining conditions is of great importance to prevention and control of rainfall-trig gered hazards. A novel rainfall rate measurement method based on videos is proposed in this paper. First, raindrops are detected based on their intensity variation characteristics in the rain images. Secondly, in order to estimate the sizes of raindrops when their distances to the camera are unkown,focused and defo- cused factors are integrated into the photometry model of raindrops imaging, and a discrimination method based on features of intensity differences and color tensor responses is constructed. Then, sizes of focused raindrops are calculated By perspective imaging relations and an observed raindrop size distribution (RSD) curve is built according to its definition in the field of meteorological science. Finally,in order to suppress noises in the observed raindrop size distribution,the observed RSD curve is fitted with the me- teorological Gamma distribution model, and rainfall rate is calculated based on the parameters of the model. In the experiments, the algorithm is tested under different rainy conditions, such as light rain, moderate rain and heavy rain. Measurement results using the proposed algorithm are compared with the data recorded by a pluviometer. It is shown that the results are consistent very well.