According to the characteristics of radar image, a method of image segmentation is suggested by performing threshold processing directly after edge detection instead of close curves.

根据雷达图像的特点提出边缘检测后不做曲线闭合，而直接进行阈值处理的图像分割。

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The water reached the northern edge of Sumatra about twenty minutes after the earthquake.

VOA: special.2009.03.17

With counting under way in the north, the party's ambitions are on a knife edge after a dramatic night of results.

BBC: Vote 2011: Labour assembly majority is on a knife edge

The Islanders had a 22-11 edge in shots on goal at that point, and they extended their edge after two periods to 28-13.

WSJ: Penguins End Islanders' Season

Earls, who has just turned 21, has been in electric form for Munster this season after failing to edge his way into the team last season.

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