Tesseract-OCR 無法識別單個圖像中的多個字符

Question

我是 Tesseract-OCR 的初學者，我正在 Python 中做這個項目，以識別一個圖像中的多個分隔字符。 我查找了 PyTesseract 的文檔，但找不到任何用於檢測不同位置的多個字符的參考。

我嘗試更改配置，但仍然無法檢測到任何字符。 我的想法是掃描圖像上的可用字符，打印它們的邊界框並找到每個邊界框的中心，以度數打印出字符的旋轉。

誰能幫我？ 謝謝。

Answer 1

也許這就是你的意思。

import cv2
import numpy as np
import pytesseract
import imutils

img = cv2.imread("srj8n.png")
cv2.imshow("original", img)

# turn into gray for next processing
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)


thresh = cv2.threshold(gray, 0, 255, cv2.THRESH_BINARY_INV * cv2.THRESH_OTSU)[1]
thresh = cv2.bitwise_not(thresh)

# omit the underline
kernel = np.ones((4, 4), np.uint8)
erosion = cv2.erode(thresh, kernel, iterations=1)

# dilate to make the line thicker
kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (9, 12))
dilation = cv2.dilate(erosion, kernel, iterations=1)

# find the contour
cntrs = cv2.findContours(dilation, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
cntrs = cntrs[0] if len(cntrs) == 2 else cntrs[1]

result = img.copy()
for c in cntrs:
    # for each letter, create red rectangle
    x, y, w, h = cv2.boundingRect(c)
    cv2.rectangle(result, (x, y), (x + w, y + h), (0, 0, 255), 2)

    # prepare letter for OCR
    box = thresh[y:y + h - 2, x:x + w]
    box = cv2.bitwise_not(box)
    box = cv2.GaussianBlur(box, (3, 3), 0)

    # retreive the angle. For the meaning of angle, see below
    # https://namkeenman.wordpress.com/2015/12/18/open-cv-determine-angle-of-rotatedrect-minarearect/
    rect = cv2.minAreaRect(c)
    angle = rect[2]

    # put angle below letter
    font = cv2.FONT_HERSHEY_SIMPLEX
    bottomLeftCornerOfText = (x, y+h+20)
    fontScale = 0.6
    fontColor = (255, 0, 0)
    lineType = 2
    cv2.putText(result, str(angle), bottomLeftCornerOfText, font, fontScale, fontColor, lineType)

    # do the OCR
    custom_config = r'-l eng --oem 3 --psm 10'
    text = pytesseract.image_to_string(box, config=custom_config)
    print("Detected :" + text + ", angle: " + str(angle))

cv2.imshow("result", result)

cv2.waitKey(0)
cv2.destroyAllWindows()