A front extraction method for a raster image of sea surface temperature (SST) is presented. Considering that the front was distributed unevenly, a low-pass filter is used to smooth the SST gradient image. The gradient image is then divided into target and background parts by a split threshold calculated from the iteration algorithm. By mathematical morphology image thinning, a SST front skeleton is extracted from the target one, and the tiny branches are trimmed. After ihe vectorization of the SST front skeleton, the vectorized SST front lines are smoothed using the erasing angle method. An example of SST front extracting process in the west Pacific is presented at last The results show that the method is feasible and effective.%提出一种海面温度栅格图的锋面提取方法.针对海洋表层温度(SST)锋面强度分布不均匀的特点,利用低通滤波对表温梯度图像进行平滑.再利用迭代法确定出梯度图像的分割阈值,将图像分割成目标与背景两部分.通过数学形态学中图像细化的方法,提取海洋温度锋面的骨架并对细小分枝进行修剪.经矢量化生成锋面线后,利用抹角法对折线进行光滑.最后以西太平洋为例,给出了一个表温锋面提取的实例,表明利用此方法进行海表温度锋面的提取是可行与有效的.
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