python车牌识别_python实现车牌识别的示例代码

车牌识别是计算机视觉领域的一个热门应用，Python也有很多成熟的实现方法。以下是一个基于OpenCV和Tesseract OCR的Python车牌识别示例代码，供参考：

import cv2
import pytesseract

# 车牌识别函数
def license_plate_recognition(image_path):
    # 读取图片
    img = cv2.imread(image_path)

    # 转为灰度图
    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

    # 边缘检测
    edges = cv2.Canny(gray, 100, 200)

    # 膨胀处理
    kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (3, 3))
    dilated = cv2.dilate(edges, kernel)

    # 查找轮廓
    contours, hierarchy = cv2.findContours(dilated, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

    # 筛选车牌轮廓
    plate_contour = None
    for contour in contours:
        x, y, w, h = cv2.boundingRect(contour)
        if w > h * 2 and w < h * 6 and w > img.shape[1] / 10 and h > img.shape[0] / 10:
            plate_contour = contour
            break

    # 裁剪出车牌区域
    if plate_contour is not None:
        x, y, w, h = cv2.boundingRect(plate_contour)
        plate_img = img[y:y+h, x:x+w]

        # OCR识别车牌号
        plate_number = pytesseract.image_to_string(plate_img, lang='chi_sim')
        return plate_number

    return None

# 示例用法
if __name__ == '__main__':
    image_path = 'test.jpg'
    plate_number = license_plate_recognition(image_path)
    if plate_number is not None:
        print('车牌号：', plate_number)
    else:
        print('未识别出车牌号')

需要注意的是，这里使用了Tesseract OCR来识别车牌号，需要先安装Tesseract和pytesseract库。