属性错误：'NoneType'对象没有属性'copy'错误

Question

代码：

import cv2
import numpy as np
import pytesseract
from  PIL import Image
class Recognition:
def ExtractNumber(self):
Number='testimg3.jpg' 
img=cv2.imread(Number, cv2.IMREAD_COLOR)
copy_img=img.copy()
img2=cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
cv2.imwrite('gray.jpg',img2)
blur = cv2.GaussianBlur(img2,(3,3),0)
cv2.imwrite('blur.jpg',blur)
canny=cv2.Canny(blur,100,200)
cv2.imwrite('canny.jpg',canny)
cnts,contours,hierarchy  = cv2.findContours(canny, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
box1=[]
f_count=0
select=0
plate_width=0

for i in range(len(contours)):
cnt=contours[i]          
area = cv2.contourArea(cnt)
x,y,w,h = cv2.boundingRect(cnt)
rect_area=w*h  #area size
aspect_ratio = float(w)/h # ratio = width/height

if  (aspect_ratio>=0.2)and(aspect_ratio<=1.0)and(rect_area>=100)and(rect_area<=700): 
cv2.rectangle(img,(x,y),(x+w,y+h),(0,255,0),1)
box1.append(cv2.boundingRect(cnt))

for i in range(len(box1)): ##Buble Sort on python
for j in range(len(box1)-(i+1)):
if box1[j][0]>box1[j+1][0]:
temp=box1[j]
box1[j]=box1[j+1]
box1[j+1]=temp

#to find number plate measureing length between rectangles
for m in range(len(box1)):
count=0
for n in range(m+1,(len(box1)-1)):
delta_x=abs(box1[n+1][0]-box1[m][0])
if delta_x > 150:
break
delta_y =abs(box1[n+1][1]-box1[m][1])
if delta_x ==0:
delta_x=1
if delta_y ==0:
delta_y=1           
gradient =float(delta_y) /float(delta_x)
if gradient<0.25:
count=count+1
#measure number plate size         
if count > f_count:
select = m
f_count = count;
plate_width=delta_x
cv2.imwrite('snake.jpg',img)


number_plate=copy_img[box1[select][1]-10:box1[select][3]+box1[select][1]+20,box1[select][0]-10:140+box1[select][0]] 
resize_plate=cv2.resize(number_plate,None,fx=1.8,fy=1.8,interpolation=cv2.INTER_CUBIC+cv2.INTER_LINEAR) 
plate_gray=cv2.cvtColor(resize_plate,cv2.COLOR_BGR2GRAY)
ret,th_plate = cv2.threshold(plate_gray,150,255,cv2.THRESH_BINARY)

cv2.imwrite('plate_th.jpg',th_plate)
kernel = np.ones((3,3),np.uint8)
er_plate = cv2.erode(th_plate,kernel,iterations=1)
er_invplate = er_plate
cv2.imwrite('er_plate.jpg',er_invplate)
result = pytesseract.image_to_string(Image.open('er_plate.jpg'), lang='kor')
return(result.replace(" ",""))

recogtest=Recognition()
result=recogtest.ExtractNumber()
print(result)

错误：

Traceback (most recent call last):
File "c:pythonopencvcarnum_2project_pytesseract.py", line 82, in <module>     
result=recogtest.ExtractNumber()
File "c:pythonopencvcarnum_2project_pytesseract.py", line 12, in ExtractNumber
copy_img=img.copy()
AttributeError: 'NoneType' object has no attribute 'copy'

Answer 1

检查图像的路径和图像文件名。也许您弄错了路径名或文件名。

检查以下行：

Number='testimg3.jpg'
img=cv2.imread(Number, cv2.IMREAD_COLOR)