Then Canny operator is adopted to detect the boder of the character image . Then the image is projected and tire mark area is located according to the wave crests and troughs of projection image .

然后针对图像的特点采用canny算子对图像进行边缘检测，对检测后图像进行投影，根据投影图像的波峰 波谷，进行第一次 标识区域定位。