python3使用Pillow、tesseract-ocr与pytesseract模块的图片识别

1.安装Pillow

pip install Pillow

2.安装tesseract-ocr

github地址: https://github.com/tesseract-ocr/tesseract

windows:

The latest installer can be downloaded here: tesseract-ocr-setup-3.05.01.exe and tesseract-ocr-setup-4.00.00dev.exe (experimental). 

ubuntu:

sudo apt-get install tesseract-ocr

traineddata文件路径: /usr/share/tesseract-ocr/tessdata/

3.安装pytesseract

pip install pytesseract

如不能使用pip直接安装可取搜索模块文件直接安装

遇到问题及解决：

1.FileNotFoundError: [WinError 2] 系统找不到指定的文件

解决办法：

方法1[推荐]: 将tesseract.exe添加到环境变量PATH中，

例如: D:\Tesseract-OCR,默认路径为C:\Program Files (x86)\Tesseract-OCR

注意: 为了使环境变量生效，需要关闭cmd窗口或是关闭pycharm等ide重新启动

方法2: 修改pytesseract.py文件，指定tesseract.exe安装路径

# CHANGE THIS IF TESSERACT IS NOT IN YOUR PATH, OR IS NAMED DIFFERENTLY
tesseract_cmd = 'C:\\Program Files (x86)\\Tesseract-OCR\\tesseract.exe‘

方法3:  在实际运行代码中指定

pytesseract.pytesseract.tesseract_cmd = 'D:\\Tesseract-OCR\\tesseract.exe'

2.pytesseract.pytesseract.TesseractError: (1, 'Error opening data file \\Tesseract-OCR\\tessdata/eng.traineddata')

 解决方法:

方法1[推荐]: 

将tessdata目录的上级目录所在路径(默认为tesseract-ocr安装目录)添加至TESSDATA_PREFIX环境变量中

例如: C:\Program Files (x86)\Tesseract-OCR

Please make sure the TESSDATA_PREFIX environment variable is set to the parent directory of your "tessdata" directory.

 

方法2:  在.py文件配置中指定tessdata-dir

tessdata_dir_config = '--tessdata-dir "D:\\Tesseract-OCR\\tessdata"'
# tessdata_dir_config = '--tessdata-dir "'C:\\Program Files (x86)\\Tesseract-OCR\\tessdata"'
pytesseract.image_to_string(image, config=tessdata_dir_config)

trainedata下载地址: the latest from github.com

示例：

# -*-coding:utf-8-*-  
from PIL import Image  
import sys  
import os  
import pytesseract
from selenium import webdriver  
sys.path.append('C:\Python27\Lib\site-packages\pytesser')  
import pytesser  
url='http://192.168.24.189/system/code?0.6824490785056669'  
driver = webdriver.Firefox()  
driver.maximize_window()  #将浏览器最大化  
driver.get(url)  
imgelement = driver.find_element_by_id('codeImg')  #定位验证码  
location = imgelement.location  #获取验证码x,y轴坐标  
size=imgelement.size  #获取验证码的长宽  
rangle=(int(location['x']),int(location['y']),int(location['x']+size['width']),int(location['y']+size['height'])) #写成我们需要截取的位置坐标  
name="code.jpg"    
driver.find_element_by_id("codeImg").click()  
driver.save_screenshot(name)  #截取当前网页，该网页有我们需要的验证码  
aa=Image.open(name) #打开截图  
frame4=aa.crop(rangle)  #使用Image的crop函数，从截图中再次截取我们需要的区域  
frame4.save(name)  
im = Image.open(name)
#转化到灰度图
imgry = im.convert('L')
#保存图像
imgry.save('g'+name)
#二值化，采用阈值分割法，threshold为分割点
threshold = 140
table = []
for j in range(256):
    if j < threshold:
        table.append(0)
    else:
        table.append(1)
out = imgry.point(table, '1')
out.save('b'+name)
#识别
text = pytesseract.image_to_string(out)
#识别对吗
text = text.strip()
text = text.upper();
print (text)
text = pytesseract.image_to_string(Image.open('code.png'), lang="eng")
print(text)