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Pytesseract简介
Pytesseract是python的光学字符识别（OCR）工具。也就是说，它将识别并读取嵌入图像中的文本。 Pytesseract是Google的Tesseract-OCR引擎的包装器。它作为独立的调用脚本也很有用，因为它可以读取Python Imaging Library支持的所有图像类型，包括jpeg，png，gif，bmp，tiff等，而tesseract-ocr默认只支持tiff和bmp。

安装
安装tesseract-ocr
sudo apt-get install tesseract-ocr               
安装语言库
tesseract-ocr-eng是英文库，tesseract-ocr-chi-sim是中文库

sudo apt-get install tesseract-ocr-eng tesseract-ocr-chi-sim            
安装依赖及pytesseract
pytesseract是python调用谷歌tesseract-ocr工具的一个库，用于识别图片中的信息

# 安装Pillow
sudo pip3 install Pillow
# 安装pytesseract
sudo pip3 install pytesseract           
使用
try:
    from PIL import Image
except ImportError:
    import Image
import pytesseract

# 如果PATH中没有tesseract可执行文件，请指定tesseract路径
pytesseract.pytesseract.tesseract_cmd = r'<full_path_to_your_tesseract_executable>'
# Example tesseract_cmd = r'/usr/share/tesseract'

# 识别的图像的字符串
print(pytesseract.image_to_string(Image.open('test.png')))

# 指定语言识别图像字符串,eng为英语
print(pytesseract.image_to_string(Image.open('test-european.jpg'), lang='fra'))

# In order to bypass the image conversions of pytesseract, just use relative or absolute image path
# NOTE: In this case you should provide tesseract supported images or tesseract will return error
print(pytesseract.image_to_string('test.png'))

# Batch processing with a single file containing the list of multiple image file paths
print(pytesseract.image_to_string('images.txt'))

# Timeout/terminate the tesseract job after a period of time
try:
    print(pytesseract.image_to_string('test.jpg', timeout=2)) # Timeout after 2 seconds
    print(pytesseract.image_to_string('test.jpg', timeout=0.5)) # Timeout after half a second
except RuntimeError as timeout_error:
    # Tesseract processing is terminated
    pass

# 获取图像边界框
print(pytesseract.image_to_boxes(Image.open('test.png')))

# 获取包含边界框，置信度，行和页码的详细数据
print(pytesseract.image_to_data(Image.open('test.png')))

# 获取方向和脚本检测
print(pytesseract.image_to_osd(Image.open('test.png')))

# Get a searchable PDF
pdf = pytesseract.image_to_pdf_or_hocr('test.png', extension='pdf')
with open('test.pdf', 'w+b') as f:
    f.write(pdf) # pdf type is bytes by default

# Get HOCR output
hocr = pytesseract.image_to_pdf_or_hocr('test.png', extension='hocr')
示例
提取本地图片上的文字为一个整体的字符串

def get_image_string(path, filename):
    '''使用谷歌开源框架ocr技术提取图片上的信息为字符串

    :Param path: <str> 图片的位置

    :Param filename: <str> 图片的名称

    :Return : <string> 从图片中提取的字符串

    '''
    username = getpass.getuser()
    path_base = '/home/' + str(username) + '/' + str(path) + '/' + str(filename) + '.png'
    text = pytesseract.image_to_string(Image.open(path_base), lang="chi_sim").replace(" ", "").replace("
", "")
    print(text)
    return text