python提取车牌轮廓

import cv2

读取图片

rawImage = cv2.imread(“D:/tupian/chepai1.jpg”)

高斯模糊，将图片平滑化，去掉干扰的噪声

image = cv2.GaussianBlur(rawImage, (3, 3), 0)

图片灰度化

image = cv2.cvtColor(image, cv2.COLOR_RGB2GRAY)

Sobel算子（X方向）

Sobel_x = cv2.Sobel(image, cv2.CV_16S, 1, 0)
absX = cv2.convertScaleAbs(Sobel_x) # 转回uint8
image = absX

二值化：图像的二值化，就是将图像上的像素点的灰度值设置为0或255,图像呈现出明显的只有黑和白

ret, image = cv2.threshold(image, 0, 255, cv2.THRESH_OTSU)

闭操作：闭操作可以将目标区域连成一个整体，便于后续轮廓的提取。

kernelX = cv2.getStructuringElement(cv2.MORPH_RECT, (17, 5))
image = cv2.morphologyEx(image, cv2.MORPH_CLOSE, kernelX)

膨胀腐蚀(形态学处理)

kernelX = cv2.getStructuringElement(cv2.MORPH_RECT, (20, 1))
kernelY = cv2.getStructuringElement(cv2.MORPH_RECT, (1, 19))
image = cv2.dilate(image, kernelX)
im