Python OpenCV招商银行信用卡卡号识别的方法

import cv2 as cv
import numpy as np
# 读取灰度图
src = cv.imread("./ka1.jpg", 0)

# 寻找卡号目标区域
roi = src[142:168, 42:360]
# cv.imshow("roi",roi)

# 寻找卡号目标区域
roi = src[142:168, 46:364]
cv.imshow("roi",roi)

# 模糊卷积操作
blur_roi = cv.blur(roi,(5,5))
cv.imshow("blur_roi",blur_roi)

med_roi = cv.medianBlur(roi,5)
cv.imshow("med_roi",med_roi)

gau_roi = cv.GaussianBlur(roi,(7,7),0)
cv.imshow("gau_roi",gau_roi)

# 对目标区域进行二值化操作
ret, thresh = cv.threshold(
  gau_roi, 0, 255, cv.THRESH_BINARY | cv.THRESH_OTSU)
cv.imshow("thresh", thresh)

# 腐蚀
kernel = np.ones((3, 4), np.uint8)
dst = cv.erode(thresh, kernel=kernel)

# 腐蚀
kernel = np.ones((3, 4), np.uint8)
erode_dst = cv.erode(thresh, kernel=kernel)
cv.imshow("erode_dst", erode_dst)
# 膨胀
kernel = np.ones((4, 4), np.uint8)
dilate_dst = cv.dilate(erode_dst, kernel=kernel)

# 检测外轮廓
# 只检测外轮廓
contours, hierarchy = cv.findContours(dilate_dst, cv.RETR_EXTERNAL, cv.CHAIN_APPROX_SIMPLE)

print(len(contours))

target_list = []
# 轮廓判断
for cnt in contours:

  # 轮廓面积
  area = cv.contourArea(cnt)
  print(area)
  if area > 79:
    target_list.append(cnt)

print(len(target_list))

for index, cnt in enumerate(target_list):
  # 外接矩形
  x, y, w, h = cv.boundingRect(cnt)
  # 在二值化的图像上进行目标区域获取
  c_roi = roi[y:y+h, x:x+w]
  # 调整图像大小
  # big_roi = cv.resize(c_roi, dsize=(0, 0), fx=2, fy=2)
  # big_roi = cv.resize(c_roi, dsize=(0, 0))
  cv.imshow("big_roi"+str(index), c_roi)
  # cv.imwrite(f"./numbers/ka_{index}.png", big_roi)

big_roi = cv.resize(c_roi, dsize=(42, 66))
# cv.imshow("c_roi"+str(index), c_roi)
cv.imwrite(f"./numbers/ka1_{index}.png", big_roi)

import cv2 as cv
import os

def walk_file(file):
  for root, dirs, files in os.walk(file):
    for f in files:
      file = os.path.join(root, f)
      # 读取灰度图
      basename = os.path.basename(file)
      filename = basename.split(".")[0]
      src = cv.imread(file, 0)
      ret, thresh = cv.threshold(src, 0, 255, cv.THRESH_BINARY | cv.THRESH_OTSU)
      # cv.imshow("thresh", thresh)
      cv.imwrite(f"./numbers/001_{filename}_bit.png", thresh)
      cv.waitKey()
      cv.destroyAllWindows()

if __name__ == "__main__":
  walk_file("./numbers")