讲道理90%的工作都是在做图像处理。。。。opencv各种操作。
一完工赶紧专心复习emmmm
大致步骤：
首先必要的库
import cv2 import numpy as np import matplotlib.pyplot as plt import pytesseract from PIL import Image import os from PyQt5 import QtCore, QtGui, QtWidgets, Qt from PyQt5.QtCore import * from PyQt5.QtWidgets import *
① 预处理（灰度，直方图均衡，滤波）
def stechCr(img):
dst = cv2.equalizeHist(img)
if debug:
cv2.imshow('dst',dst)
cv2.waitKey(0)
cv2.destroyAllWindows()
return dst
gray = cv2.fastNlMeansDenoisingColored(img, None, 10, 3, 3, 3)
gray=cv2.cvtColor(gray,cv2.COLOR_BGR2GRAY)
img,gray=makepic(gray)
② 提取ROI，主要用opencv的findContours找到背景下最大的轮廓，也就是卡面本身。
def makepic(Img):
Img=stechCr(Img)
ret, img = cv2.threshold(Img, lot, 255, cv2.THRESH_BINARY)
image, contours, hierarchy = cv2.findContours(img, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
res=contours[0]
carea=cv2.contourArea(res)
tmpImg=Img
cv2.drawContours(tmpImg,contours,-1,(0,0,255),3)
cv2.imwrite('contours.png',tmpImg)
for i in range(len(contours)):
cnt=contours[i]
narea=cv2.contourArea(cnt)
if carea < narea :
carea=narea
res=cnt
rect = cv2.minAreaRect(res)
box = cv2.boxPoints(rect)
box = np.int0(box)
h = abs(box[0][1] - box[2][1])
w = abs(box[0][0] - box[2][0])
Xs = [i[0] for i in box]
Ys = [i[1] for i in box]
x1 = min(Xs)
y1 = min(Ys)
r1=cv2.resize(Img[y1:y1 + h, x1:x1 + w],(560*2,340*2),interpolation=cv2.INTER_CUBIC)
r2=cv2.resize(img[y1:y1 + h, x1:x1 + w],(560*2,340*2),interpolation=cv2.INTER_CUBIC)
if debug:
cv2.imshow('ROI',Img[y1:y1 + h, x1:x1 + w])
cv2.waitKey(0)
cv2.destroyAllWindows()
return r1,r2
③ （这里还应该做一个镜头角度矫正，但是我还没搞明白那个东西所以就没做了
④ ROI反向二值化，然后膨胀。膨胀后的效果如下图（上面的过程比较简单而且泄露个人信息就不放了。。。。）
def prepare(gray):
ret, binary = cv2.threshold(gray, lot, 255, cv2.THRESH_BINARY_INV)#反向二值化
opening=binary
ele = cv2.getStructuringElement(cv2.MORPH_RECT, (17, 17))
dilation = cv2.dilate(opening, ele, iterations=1)#膨胀操作
cv2.imwrite("BI_img.png", binary)
cv2.imwrite("AfterDilate.png", dilation)
if debug :
cv2.imshow("BI_img", binary)
cv2.waitKey(0)
cv2.destroyAllWindows()
cv2.imshow("AfterDilate", dilation)
cv2.waitKey(0)
cv2.destroyAllWindows()
return dilation
⑤ 找出文本区域：再用一次findContours，找出来各个白色块的轮廓，然后用cv2.minAreaRect()找到最小包围矩形，并且把不符号要求的矩形都剔除掉（太长太宽太大太小之类的，参数需要调），最后找到的区域切割出去。
def findTextRegion(img):
region = []
# 查找膨胀块轮廓
image, contours, hierarchy = cv2.findContours(img, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
for i in range(len(contours)):
cnt = contours[i]
area = cv2.contourArea(cnt)
# 面积过大过小的都去掉
if (area < 4*1500 or area >2*15000):#调参使得适合一卡通
continue
# 找到最小的矩形，该矩形可能有方向
rect = cv2.minAreaRect(cnt)
# box是四个点的坐标
box = cv2.boxPoints(rect)
box = np.int0(box)
height = abs(box[0][1] - box[2][1])
width = abs(box[0][0] - box[2][0])
# 筛选矩形
if (height > width * 1.2):
continue
if (height * 15 < width): continue #if (width > img.shape[1] / 2 and height > img.shape[0] / 20):
region.append(box)
return region
方框图出来的结果
切割出来的各个小块
⑥ 最后就是把切割出来的图片送给pytessract-ocr输出就可以了，我这里是存在了infoDict的字典里。
def ocrIdCard(imgPath):
fc=len(imgPath)
pre="";af=""
for i in range(fc-1,-1,-1):
if imgPath[i]=="/":
pre=imgPath[:i]
af=imgPath[i+1:]
break
os.chdir(pre)
it=os.getcwd()
img = cv2.imread(af)
infoDict={"学号":"",
"姓名":"",
"学院":"",
"班级":""
}
print('start...\n')
idImgs = detect(img)
tessdata_dir_config = '--tessdata-dir "C:\\Program Files (x86)\\Tesseract-OCR\\tessdata"'
tesseract_cmd = "C:\\Program Files (x86)\\Tesseract-OCR\\tesseract.exe"
i=1
for idImg in idImgs:
#print(i)
if debug:
cv2.imshow('temp'+str(i),idImg)
cv2.waitKey(0)
cv2.destroyAllWindows()
image = Image.fromarray(idImg)
result = pytesseract.image_to_string(image, lang='chi_sim',config=tessdata_dir_config,)
result=result.replace(' ','')
if(len(result)!=0):
flag=1
for a in result:
if (a<='z' and a>='a') or (a<='Z' and a>='A'):
flag=0
break
if flag:
if len(result) == 11:
infoDict["学号"]=result
elif len(result) == 7:
infoDict["班级"]=result
elif result[-2:]=="学院":
infoDict["学院"]=result
else:
infoDict["姓名"]=result
i+=1
return infoDict
⑦ 图形化界面，话说从C#过来的我用python写图形化真的是难受的一批。。PyQt真的相比C#太弟弟了。。
class oneCardOcrUi(QtWidgets.QWidget):
def __init__(self):
super(oneCardOcrUi,self).__init__()
self.setupUi()
self.infoCard={}
def setupUi(self):
self.setWindowTitle("一卡通识别")
self.layout = QtWidgets.QGridLayout()
layout=self.layout
self.setGeometry(600, 600, 400, 400)
self.nameLabel = QtWidgets.QLabel("姓名")
self.nameLineEdit = QtWidgets.QLineEdit("")
self.idLabel = QtWidgets.QLabel("学号")
self.idLineEdit = QtWidgets.QLineEdit("")
self.scLabel = QtWidgets.QLabel("学院")
self.scLineEdit = QtWidgets.QLineEdit("")
self.clLabel = QtWidgets.QLabel("班级")
self.clLineEdit = QtWidgets.QLineEdit("")
layout.addWidget(self.nameLabel,1,0)
layout.addWidget(self.nameLineEdit,1,1)
layout.addWidget(self.idLabel, 2, 0)
layout.addWidget(self.idLineEdit, 2, 1)
layout.addWidget(self.scLabel,3,0)
layout.addWidget(self.scLineEdit,3,1)
layout.addWidget(self.clLabel,4,0)
layout.addWidget(self.clLineEdit,4,1)
layout.setColumnStretch(1, 10)
open_Btn = QtWidgets.QPushButton('打开图片')
save_Btn = QtWidgets.QPushButton('保存为csv')
save_Btn.clicked.connect(self.savefile)
open_Btn.clicked.connect(self.openfile)
layout.addWidget(open_Btn)
layout.addWidget(save_Btn)
self.setLayout(layout)
self.show()
def savefile(self):
savefile_name=QtWidgets.QFileDialog.getSaveFileName(self,'选择存储方式','','csv文件(*.csv )')
if debug:
print(savefile_name)
print(self.infoCard)
if savefile_name is None:
return
dataframe = pd.DataFrame(self.infoCard,index=[0])
dataframe.to_csv(savefile_name[0],index=[0],sep=',',encoding="utf_8_sig")
def openfile(self):
openfile_name = QtWidgets.QFileDialog.getOpenFileName(self,'选择文件','','图片文件(*.jpeg , *.png, *.jpg)')
if openfile_name is None:
return
self.infoCard=ocrIdCard(openfile_name[0])
self.nameLineEdit.setText(self.infoCard["姓名"])
self.idLineEdit.setText(self.infoCard["学号"])
self.scLineEdit.setText(self.infoCard["学院"])
self.clLineEdit.setText(self.infoCard["班级"])
if debug:
print(self.infoCard)
print(self.nameLineEdit.text())
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
ui = oneCardOcrUi()
#ui.setupUi()这两行坑了我好久。。。mmp写在外面就不能实时刷新文本框了
#ui.show()
sys.exit(app.exec_())
最后是几个过程中遇到的bug和解决方法
-
Cannot find existing PyQt5 plugin directories 解决：https://blog.csdn.net/poppyque/article/details/85256241
- UnicodeDecodeError: ‘utf-8’ codec can’t decode byte 0xce in position 130: invalid continuation b 解决：https://blog.csdn.net/qq_41185868/article/details/80599390
-
打包完成后双击exe出现的bug：This application failed to start because it could not find or load the Qt platform plugin “windows 解决：https://blog.csdn.net/Perfect_Accepted/article/details/80140362
主要参考：
https://blog.csdn.net/missyougoon/article/details/81632166
https://www.jianshu.com/p/f57165f34839
https://docs.opencv.org/3.3.0/d3/dc0/group__imgproc__shape.html#ga17ed9f5d79ae97bd4c7cf18403e1689a
https://www.jianshu.com/p/98e8218b2309
https://www.cnblogs.com/ansang/p/7895075.html
完整的代码在github