我正在尝试使用读取验证码pytesseract模块。大多数时候它都能提供准确的文本,但并非总是如此。
这是读取图像、操作图像以及从图像中提取文本的代码。
import cv2
import numpy as np
import pytesseract
def read_captcha():
# opencv loads the image in BGR, convert it to RGB
img = cv2.cvtColor(cv2.imread('captcha.png'), cv2.COLOR_BGR2RGB)
lower_white = np.array([200, 200, 200], dtype=np.uint8)
upper_white = np.array([255, 255, 255], dtype=np.uint8)
mask = cv2.inRange(img, lower_white, upper_white) # could also use threshold
mask = cv2.morphologyEx(mask, cv2.MORPH_OPEN, cv2.getStructuringElement(cv2.MORPH_ELLIPSE, (3, 3))) # "erase" the small white points in the resulting mask
mask = cv2.bitwise_not(mask) # invert mask
# load background (could be an image too)
bk = np.full(img.shape, 255, dtype=np.uint8) # white bk
# get masked foreground
fg_masked = cv2.bitwise_and(img, img, mask=mask)
# get masked background, mask must be inverted
mask = cv2.bitwise_not(mask)
bk_masked = cv2.bitwise_and(bk, bk, mask=mask)
# combine masked foreground and masked background
final = cv2.bitwise_or(fg_masked, bk_masked)
mask = cv2.bitwise_not(mask) # revert mask to original
# resize the image
img = cv2.resize(mask,(0,0),fx=3,fy=3)
cv2.imwrite('ocr.png', img)
text = pytesseract.image_to_string(cv2.imread('ocr.png'), lang='eng')
return text
对于图像的处理,我得到了帮助堆栈溢出 https://stackoverflow.com/questions/29810128/opencv-python-set-background-colour#answer-38516242 post.
这是原始的验证码图像:
这张图片是在处理后生成的:
但是,通过使用pytesseract,我收到文本:AX#7rL.
谁能指导我如何将成功率提高到100%?