| 摘要: |
| 破碎波峰线长度的速度谱() Λc 及其高阶矩是研究破碎能量耗散、动量通量等关键问题的有效工具。活跃破碎的图像识别是正确计算() Λc 的一个关键前。Kleiss等2011年给出了一种基于对数累积灰度函数(L)的导函数区分活跃破碎与尾迹的阈值方法, 但阈值的确定仍存在一定的主观性, 得到的破碎阈值可能偏低。我们通过对渤海海域拍摄的白冠破碎观测资料的分析, 发现L函数的二阶导数往往存在稳定的次峰, 次峰所对应的灰度值正可作为区分活跃破碎与尾迹的灰度阈值, 由此提出一种基于L函数二阶导数次峰的阈值确定方法。 |
| 关键词: 白冠破碎 活跃破碎 破碎尾迹 图像识别 |
| DOI：10.11693/hyhz20121220001 |
| 分类号: |
| 基金项目:国家自然科学基金, 41276010 号。 |
附件 |
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| RECOGNIZING ACTIVE WHITECAP BREAKING |
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zhangchong,leishuhe,guanchanglong and zhouxilong
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Ocean University of China,Ocean University of China,Ocean University of China,Ocean University of China
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| Abstract: |
| Phillips et al. (1985) proposed a function Λ(c) to describe statistically the effective energy dissipation and momentum flux of wave breaking. To distinguish effectively active whitecap from old foam patches is important in calculating the function. By analyzing whitecap videos in Bohai Sea, North China, we found that the second derivative of the greyness accumulation function L″show a subpeak that is persistent in different images of videos. Moreover, grayness level of the subpeak can be defined as a new gray threshold to separate between active whitecap and old foam patches, which is better than that of the Kleiss proposed in 2011. |
| Key words: whitecap breaking active breaking old foam patch image recognition |
