关键词: 牌照定位, 削峰填谷, 自适应, 边缘检测

Abstract: A weaken crest and fill trough algorithm used for license plate location is put forward.At first，this algorithm deals the obtained color image with gray，gray stretch and edge detection，so makes the area of license plate sticking out.Then the detected result is projected vertically，and deals the projection with weaken crest and fill trough adaptive targeted，and can get the left-right border of the plate，the part image between the plate’s left and right border is projected horizontally，and deal the projection with same algorithm，and also can get the top-bottom border of the plate.In the end，the license plate’s specific location is obtained.Test result proves that this algorithm locate rapidly，high accuracy and practical.

Key words: license plate location, weaken crest and fill trough, adaptation, edge detection