# process image with ros and python3

**Repository Path**: hwk0809/process-image-with-ros-and-python3

## Basic Information

- **Project Name**: process image with ros and python3
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2022-01-19
- **Last Updated**: 2022-01-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# process image with ros and python3

### 介绍
简单的图像发布与订阅示例

用于解决python3（anaconda），ros下的图像处理问题

### 环境配置

1. 依赖项安装

   - conda 环境启动

     ```
     conda activate gaofen(your environment name)
     ```

   - 在conda环境下安装必备依赖（rospkg ,opencv_python numpy pyyaml)

     ```
     pip install numpy pyyaml rospkg opencv_python -i https://pypi.tuna.tsinghua.edu.cn/simple 
     ```

     reference : https://www.guyuehome.com/33763

   - catkin tools for python

     python-catkin-tools is needed for catkin tool
     python3-dev and python3-catkin-pkg-modules is needed to build cv_bridge
     python3-numpy and python3-yaml is cv_bridge dependencies
     ros-meodic-cv-bridge is needed to install a lot of cv_bridge deps. Probaply you already have it installed.

     ```
     sudo apt-get install python-catkin-tools python3-dev python3-catkin-pkg-modules python3-numpy python3-yaml ros-melodic-cv-bridge
     ```

     

2. cv_bridge 单独编译

   - 此时可以关掉conda环境

     ```
     conda deactivate
     ```

   - 创建新的ros工作空间

     ```
     mkdir catkin_workspace 
     cd catkin_workspace 
     catkin init
     ```

   - Instruct catkin to set cmake variables

     ```
     catkin config -DPYTHON_EXECUTABLE=/usr/bin/python3 -DPYTHON_INCLUDE_DIR=/usr/include/python3.6m -DPYTHON_LIBRARY=/usr/lib/x86_64-linux-gnu/libpython3.6m.so
     ```

     

   - Instruct catkin to install built packages into install place. It is $CATKIN_WORKSPACE/install folder

     ```
     catkin config --install
     ```

   - Clone cv_bridge src

     ```
     git clone https://github.com/ros-perception/vision_opencv.git src/vision_opencv
     ```

     

   - Find version of cv_bridge in your repository

     ```
     apt-cache show ros-melodic-cv-bridge | grep Version
     ```

      显示 Version: 1.12.8-0xenial-20180416-143935-0800

   - Checkout right version in git repo. In our case it is 1.12.8

     ```
     cd src/vision_opencv/ 
     git checkout 1.12.8 
     ```

   - Build

     ```
     cd ../../
     catkin build cv_bridge
     ```

3. bash加载

   在~/.bashrc中加入 (工作空间换成当前的)

   ```
   source ~/catkin_workspace/install/setup.bash 
   source ~/catkin_workspace/devel/setup.bash 
   ```

   

if you report error: "libgcc_s.so.1 must be installed for pthread_cancel to work" you can try sys.path.remove('/opt/ros/melodic/lib/python2.7/dist-packages') or conda install -c esgf libgcc-ng reference:https://stackoverflow.com/questions/49221565/unable-to-use-cv-bridge-with-ros-kinetic-and-python3