2020系统综合实践 第7次实践作业 01组

一、在树莓派中安装opencv库

首先安装依赖，在安装过程中可能会遇到诸多“俄罗斯套娃”的依赖项，就不停地耐心安装。

pip3 install --upgrade setuptools
pip3 install numpy Matplotlib

sudo apt-get install libjpeg-dev libtiff5-dev libjasper-dev libpng12-dev
sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev
sudo apt-get install libxvidcore-dev libx264-dev
sudo apt-get install libgtk2.0-dev libgtk-3-dev
sudo apt-get install libatlas-base-dev
sudo apt install libqt4-test
sudo apt install libqtgui4

然后pip3安装opencv以及opencv，这样默认安装最新版

pip3 install opencv-python
pip3 install opencv-contrib-python

安装完毕，导入成功！

二、使用opencv和python控制树莓派的摄像头

示例代码

# import the necessary packages
from picamera.array import PiRGBArray
from picamera import PiCamera
import time
import cv2
 
# initialize the camera and grab a reference to the raw camera capture
camera = PiCamera()
rawCapture = PiRGBArray(camera)
 
# allow the camera to warmup
time.sleep(2) 
 
# grab an image from the camera
camera.capture(rawCapture, format="bgr")
image = rawCapture.array
 
# display the image on screen and wait for a keypress
cv2.imshow("Image", image)
cv2.waitKey(0)

通过摄像头实时拍摄查看视频

import cv2

cap = cv2.VideoCapture(0)
while(1):
    ret, frame = cap.read()
    cv2.imshow("capture", frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
cap.release()
cv2.destroyAllWindows() 

三、利用树莓派的摄像头实现人脸识别

1.facerec_on_raspberry_pi.py

facerec_on_raspberry_pi.py

# This is a demo of running face recognition on a Raspberry Pi.
# This program will print out the names of anyone it recognizes to the console.
# To run this, you need a Raspberry Pi 2 (or greater) with face_recognition and
# the picamera[array] module installed.
# You can follow this installation instructions to get your RPi set up:
# https://gist.github.com/ageitgey/1ac8dbe8572f3f533df6269dab35df65

import face_recognition
import picamera
import numpy as np

# Get a reference to the Raspberry Pi camera.
# If this fails, make sure you have a camera connected to the RPi and that you
# enabled your camera in raspi-config and rebooted first.
camera = picamera.PiCamera()
camera.resolution = (320, 240)
output = np.empty((240, 320, 3), dtype=np.uint8)

# Load a sample picture and learn how to recognize it.
print("Loading known face image(s)")
obama_image = face_recognition.load_image_file("Biden.jpg")
obama_face_encoding = face_recognition.face_encodings(obama_image)[0]

# Initialize some variables
face_locations = []
face_encodings = []

while True:

    print("Capturing image.")
    # Grab a single frame of video from the RPi camera as a numpy array
    camera.capture(output, format="rgb")

    # Find all the faces and face encodings in the current frame of video
    face_locations = face_recognition.face_locations(output)

    print("Found {} faces in image.".format(len(face_locations)))
    face_encodings = face_recognition.face_encodings(output, face_locations)

    # Loop over each face found in the frame to see if it's someone we know.
    for face_encoding in face_encodings:

        # See if the face is a match for the known face(s)
        match = face_recognition.compare_faces([obama_face_encoding], face_encoding)
        name = "<Unknown Person>"

        if match[0]:
            name = "Biden"
        print("I see someone named {}!".format(name))

代码所在目录下应放一张用于比对的照片，文件名Biden.jpg

2.facerec_from_webcam_faster.py

facerec_from_webcam_faster.py

import face_recognition
import cv2
import numpy as np


# This is a demo of running face recognition on live video from your webcam. It's a little more complicated than the
# other example, but it includes some basic performance tweaks to make things run a lot faster:
#   1. Process each video frame at 1/4 resolution (though still display it at full resolution)
#   2. Only detect faces in every other frame of video.

# PLEASE NOTE: This example requires OpenCV (the `cv2` library) to be installed only to read from your webcam.
# OpenCV is *not* required to use the face_recognition library. It's only required if you want to run this
# specific demo. If you have trouble installing it, try any of the other demos that don't require it instead.

# Get a reference to webcam #0 (the default one)
video_capture = cv2.VideoCapture(0)

# Load a sample picture and learn how to recognize it.
obama_image = face_recognition.load_image_file("Obama.jpg")
obama_face_encoding = face_recognition.face_encodings(obama_image)[0]

# Load a second sample picture and learn how to recognize it.
biden_image = face_recognition.load_image_file("Biden.jpg")
biden_face_encoding = face_recognition.face_encodings(biden_image)[0]

# Create arrays of known face encodings and their names
known_face_encodings = [
    obama_face_encoding,
    biden_face_encoding
]

known_face_names = [
    "Barack Obama",
    "Joe Biden"
]



# Initialize some variables
face_locations = []
face_encodings = []
face_names = []

process_this_frame = True

while True:

    # Grab a single frame of video
    ret, frame = video_capture.read()

    # Resize frame of video to 1/4 size for faster face recognition processing
    small_frame = cv2.resize(frame, (0, 0), fx=0.25, fy=0.25)

    # Convert the image from BGR color (which OpenCV uses) to RGB color (which face_recognition uses)
    rgb_small_frame = small_frame[:, :, ::-1]

    # Only process every other frame of video to save time
    if process_this_frame:

        # Find all the faces and face encodings in the current frame of video
        face_locations = face_recognition.face_locations(rgb_small_frame)
        face_encodings = face_recognition.face_encodings(rgb_small_frame, face_locations)

        face_names = []
        for face_encoding in face_encodings:
            # See if the face is a match for the known face(s)
            matches = face_recognition.compare_faces(known_face_encodings, face_encoding)
            name = "Unknown"

            # # If a match was found in known_face_encodings, just use the first one.
            # if True in matches:
            #     first_match_index = matches.index(True)
            #     name = known_face_names[first_match_index]
            # Or instead, use the known face with the smallest distance to the new face
            face_distances = face_recognition.face_distance(known_face_encodings, face_encoding)
            best_match_index = np.argmin(face_distances)
            if matches[best_match_index]:
                name = known_face_names[best_match_index]

            face_names.append(name)

    process_this_frame = not process_this_frame

    # Display the results
    for (top, right, bottom, left), name in zip(face_locations, face_names):
        # Scale back up face locations since the frame we detected in was scaled to 1/4 size
        top *= 4
        right *= 4
        bottom *= 4
        left *= 4

        # Draw a box around the face
        cv2.rectangle(frame, (left, top), (right, bottom), (0, 0, 255), 2)

        # Draw a label with a name below the face
        cv2.rectangle(frame, (left, bottom - 35), (right, bottom), (0, 0, 255), cv2.FILLED)
        font = cv2.FONT_HERSHEY_DUPLEX
        cv2.putText(frame, name, (left + 6, bottom - 6), font, 1.0, (255, 255, 255), 1)

    # Display the resulting image
    cv2.imshow('Video', frame)

    # Hit 'q' on the keyboard to quit!
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# Release handle to the webcam
video_capture.release()
cv2.destroyAllWindows()

已经学习过本地的图片

未学习过的人脸图片

四、结合微服务的进阶任务

(1).安装Docker

下载安装脚本

curl -fsSL https://get.docker.com -o get-docker.sh

执行安装脚本(使用阿里云镜像)

sh get-docker.sh --mirror Aliyun

将当前用户加入docker用户组

sudo usermod -aG docker $USER

尝试下查看docker版本

(2).配置docker的镜像加速

请参考第一次实验博客

编辑完成后，restart一下docker

service docker restart

(3).定制自己的opencv镜像

首先拉取镜像

docker pull sixsq/opencv-python

运行这个镜像

docker run -it sixsq/opencv-python /bin/bash

在容器中，安装 "picamera[array]" dlib face_recognition

pip在线安装延迟严重，采用离线安装

安装成功，退出容器
然后commit

编写Dockerfile

FROM wjx_opencv
MAINTAINER 555
RUN mkdir /myapp
WORKDIR /myapp
COPY myapp .

build

docker build -t myopencv .

(4).运行容器执行facerec_on_raspberry_pi.py

docker run -it --device=/dev/vchiq --device=/dev/video0 --name facerec myopencv
python3 facerec_on_raspberry_pi.py

如果不加--device=/dev/vchiq参数
则会出现以下报错

* failed to open vchiq instance

(5).附加选做:opencv的docker容器中运行facerec_from_webcam_faster.py

在Windows系统中安装Xming
安装过程一路默认即可(https://sourceforge.net/projects/xming/)

检查树莓派的ssh配置中的X11是否开启

cat /etc/ssh/sshd_config

然后编写run.sh

#sudo apt-get install x11-xserver-utils
xhost +
docker run -it 
        --net=host 
        -v $HOME/.Xauthority:/root/.Xauthority 
        -e DISPLAY=:10.0  
        -e QT_X11_NO_MITSHM=1 
        --device=/dev/vchiq 
        --device=/dev/video0 
        --name facerecgui 
        myopencv 
	python3 facerec_from_webcam_faster.py

sh run.sh

五、遇到的问题

（1）关于安装OpenCV的依赖

安装OpenCV，安装了一天。还是比较繁琐的。安装OpenCV的依赖，从最基础的依赖安装。

其中有依赖是套中套，在安装的过程中需要彼此依赖，比如安装gtk2与gtk3，所以我们是采用

sudo aptitude install libgtk2.0-dev libgtk-3-dev

他在遇到相互依赖时会给出解决方式，我们采取第二种方式，降低部分依赖的版本就行了（忘了截图）

（2）import cv2出现的问题

在import cv2时会出现依赖公共的库没有添加，这些就直接百度搜索，然后apt-get install 即可，可参考安装libImath-2_2.so.23 公共库

（3）undefined symbol: __atomic_fetch_add_8

在import cv2的最后一个问题

vim ~/.bashrc注意是pi用户下的bashrc，不是root下的bashrc
然后在末尾加上这段话，再source ~/.bashrc

export LD_PRELOAD=/usr/lib/arm-linux-gnueabihf/libatomic.so.1

（4）关于摄像头人脸识别

在本地放需要学习的图片，然后再通过利用树莓派摄像头进行其他图片的识别，即可。

（5）关于pip3 install安装时超时的问题（如face_recognition）

可以先再外面下载好相应的包之后，再通过winscp导入到树莓派，再离线安装

（6）在镜像里面安装"picamera[array]" dlib face_recognition时，在线安装比较延迟。

同样可以采用离线安装。通过本地下载文件，把文件复制进容器里面（docker cp file id:path），然后采用pip3离线安装方法。

六、在线协作

学号	姓名	工作
031702539	李清宇	OpenCV安装，硬件的操作，资料收集
031702547	汪佳祥	OpenCV安装，人脸识别，结合微服务，修改博客
031702521	杨忠燎	OpenCV安装，提供错误解决方案，撰写博客

通过视频，屏幕分享进行交流。成员通过TeamViewer进行远程操作，参与实验的各个步骤。

实验总共花费了整整三天，关于OpenCV的安装比较繁琐。反反复复弄了一天完成，人脸识别和结合微服务进展比较顺利。