环境配置

python离线图像识别使用tesseract库，对应python库为pytesseract。使用前需要先安装tesseract

安装文档 (opens new window) 编译安装文档 (opens new window)

windows 环境安装

mac 环境安装

编译安装

# Packages which are always needed.
brew install automake autoconf libtool
brew install pkgconfig
brew install icu4c
brew install leptonica
# Packages required for training tools.
brew install pango
# Optional packages for extra features.
brew install libarchive
# Optional package for builds using g++.
brew install gcc

git clone https://github.com/tesseract-ocr/tesseract/
cd tesseract
./autogen.sh
mkdir build
cd build
# Optionally add CXX=g++-8 to the configure command if you really want to use a different compiler.
../configure PKG_CONFIG_PATH=/usr/local/opt/icu4c/lib/pkgconfig:/usr/local/opt/libarchive/lib/pkgconfig:/usr/local/opt/libffi/lib/pkgconfig
make -j
# Optionally install Tesseract.
sudo make install
# Optionally build and install training tools.
# 下面安装用于训练工具，酌情安装
make training
sudo make training-install

安装完成后，设置环境变量

export TESSDATA_PREFIX=/usr/local/share/tessdata

执行代码会发现有报错 Error opening data file /usr/local/share/tessdata/eng.traineddata

出错原因是程序在载入训练数据，但未找到训练数据，这里我们可以从github上下载数据，地址为 https://github.com/tesseract-ocr/tessdata

或使用下面命令直接下载：

wget https://github.com/tesseract-ocr/tessdata/raw/main/eng.traineddata

代码示例

import pytesseract
from PIL import Image

img = Image.open('./num.jpg')
print(img)
text = pytesseract.image_to_string(img)
print(text)