给车牌识别代码加一个识别轮廓长宽比的代码

Question

下面这个代码是关于从照片提取车牌并识别的 能不能在筛选轮廓那里加一段筛选轮廓长宽比在2.5到4的代码

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import cv2
import imutils
import pytesseract
import numpy as np
pytesseract.pytesseract.tesseract_cmd = 'C:\\Program Files\\Tesseract-OCR\\tesseract.exe'
original_image = cv2.imread('img.jpg')
original_image = imutils.resize(original_image, width=500 )
gray_image = cv2.cvtColor(original_image, cv2.COLOR_BGR2GRAY)
gray_image = cv2.bilateralFilter(gray_image, 11, 17, 17)
edged_image = cv2.Canny(gray_image, 30,200)
contours, new = cv2.findContours(edged_image.copy(), cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
img1 = original_image.copy()
cv2.drawContours(img1, contours, -1, (0, 255, 0), 3)
cv2.imshow("img1", img1)
contours = sorted(contours, key=cv2.contourArea, reverse=True)[:30]
screenCnt = None
img2 = original_image.copy()
cv2.drawContours(img2, contours, -1, (0, 255, 0), 3)
cv2.imshow("img2", img2)
count = 0
idx = 7
car_contours = []

for c in contours:
    contour_perimeter = cv2.arcLength(c, True)
    approx = cv2.approxPolyDP(c, 0.018 * contour_perimeter, True)

    if len(approx) == 4:
        screenCnt = approx

        x, y, w, h = cv2.boundingRect(c)
        new_img = original_image[y: y + h, x: x + w]

        cv2.imwrite('./' + str(idx) + '.png', new_img)
        idx += 1
        break

cv2.drawContours(original_image, [screenCnt], -1, (0, 255, 0), 3)
cv2.imshow("detected license plate", original_image)

cropped_License_Plate = './7.png'
cv2.imshow("cropped license plate", cv2.imread(cropped_License_Plate))

text = pytesseract.image_to_string(cropped_License_Plate, lang='eng')
print("License plate is:", text)
cv2.waitKey(0)
cv2.destroyAllWindows()

Answer 1

import cv2
import imutils
import pytesseract

pytesseract.pytesseract.tesseract_cmd = 'C:\\Program Files\\Tesseract-OCR\\tesseract.exe'
original_image = cv2.imread('img.jpg')
original_image = imutils.resize(original_image, width=500)
gray_image = cv2.cvtColor(original_image, cv2.COLOR_BGR2GRAY)
gray_image = cv2.bilateralFilter(gray_image, 11, 17, 17)
edged_image = cv2.Canny(gray_image, 30, 200)
contours, new = cv2.findContours(edged_image.copy(), cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
img1 = original_image.copy()
cv2.drawContours(img1, contours, -1, (0, 255, 0), 3)
cv2.imshow("img1", img1)
contours = sorted(contours, key=cv2.contourArea, reverse=True)[:30]
screenCnt = None
img2 = original_image.copy()
cv2.drawContours(img2, contours, -1, (0, 255, 0), 3)
cv2.imshow("img2", img2)
count = 0
idx = 7
car_contours = []

for c in contours:
    contour_perimeter = cv2.arcLength(c, True)
    approx = cv2.approxPolyDP(c, 0.018 * contour_perimeter, True)

    if len(approx) == 4:
        x, y, w, h = cv2.boundingRect(c)
        aspect_ratio = float(w) / h

        if 2.5 <= aspect_ratio <= 4:
            screenCnt = approx

            new_img = original_image[y: y + h, x: x + w]
            cv2.imwrite('./' + str(idx) + '.png', new_img)
            idx += 1
            break

cv2.drawContours(original_image, [screenCnt], -1, (0, 255, 0), 3)
cv2.imshow("detected license plate", original_image)

cropped_License_Plate = './7.png'
cv2.imshow("cropped license plate", cv2.imread(cropped_License_Plate))

text = pytesseract.image_to_string(cropped_License_Plate, lang='eng')
print("License plate is:", text)
cv2.waitKey(0)
cv2.destroyAllWindows()