1、 Transmission of file stream on Web page

One 、flask.request.files[‘file’] Method

Flask Of files Method can be used to transfer all kinds of documents , Take video transmission as an example .

1. Client code ：（ Focus on files Assembly method ）
   file type ： The document passed over is the type of dictionary （files = {‘file’:img_data}）

 Picture data ：binary（ Binary system ） Type upload .
 file type ： The document passed over is the type of dictionary （files = {'file':img_data}）

import requests
import json
#todo  use open Read 
with open('./666051400.mp4','rb') as f:
    video_data = f.read()  # type ： <class 'bytes'>
    files = {
    'file':video_data,"card_json":open(json_path,'rb'),}
data = {
    'video_type':'mp4','unique_msg':'yfqtest0328','add_sign':0}
r = requests.post('http://127.0.0.1:8000/searchmp4', data, files=files) # Be sure to point out files=files
print(json.loads(r.text))

#todo  use opencv Read 
img=cv2.imread(path,cv2.IMREAD_COLOR)
imgRGB=cv2.cvtColor(img,cv2.IMREAD_COLOR) # turn rgb   Actually, it's OK not to transfer , Skip this step directly 
r,buf=cv2.imencode(".jpg",imgRGB)  # Image coding 
bytes_image=Image.fromarray(np.uint8(buf)).tobytes() #array convert to image Re turn bytes
files = {
    'file': bytes_image}
r = requests.post(url, files=files)
print(r.text)

2. Server code ：（ Focus on files Receiving method ）

import json,requests
import base64
import numpy as np
from  PIL import  Image
import flask
import io,cv2
from io import BytesIO,StringIO

app=flask.Flask(__name__)
@app.route("/",methods=["GET","POST"])
def registered_user():
    print("wo")
    try:
    	if request.method == "POST":
    	 	video_type = request.form.get('video_type')
        	video_data.save('123.mp4')
	        get_file=flask.request.files["file"]  # Upload files ---><FileStorage: '71e630263c7ac3eb967420224c63bec.png' ('image/png')>
	        pic=get_file.read()  # Read the content , A lot of crap    <class 'bytes'>
	        user_image=Image.open(BytesIO(pic)) #BytesIO It can read and write in memory bytes
	        arry_image=np.array(user_image)
	        # cv2.imwrite("query.jpg",arry_image)  # Save to local 
	        # '.jpg' Means to put the current picture img according to jpg Format encoding 
	        pic1=cv2.imencode(".jpg",arry_image)[1].tostring() #.tostring() take number Object to string 
	        pic2=base64.b64encode(pic1)  # Use base64 Encode byte like objects  s, And return a byte object .
	        register_data={
    "Pic":pic2.decode()}
	        data=json.dumps(register_data) # Will a Python The data structure is converted to JSON
	
	        url='http://localhost:8888/detect_line'
	        r=requests.post(url,data) # send out post request 

        	return json.loads(r.content)["results"]  # The output file is json Format output in this format .
    except Exception  as e:
        import logging
        logging.exception(e)
        return "error"

# The above is the data conversion 

Two 、flask.request.get_data() Method

Flask Of get_data() Method can be used to transmit pictures as an example .

1. Client code

 Picture data ： Turn the picture into base64 data type 
 File data ：json Upload in file form .register_data = {'Pic': pic.decode(), 'Card_Json': json_file}

def cv_imread(file_path):
    #  Read Chinese path 
    cv_img = cv2.imdecode(np.fromfile(file_path, dtype=np.uint8), -1)
    return cv_img
path=r"/data2/enducation/answer_card/answer-card-recognition/pic/2021-08-17_14_16_18.jpg"
pic = main.cv_imread(path)
 pic = cv_imread(path)
 pic = np.asarray(pic) # turn nparry
 pic = cv2.imencode('.jpg', pic)[1].tobytes()  # Use UTF-8 code , Re turn bytes
 #json Only string format transmission is supported , So use base64 code , This process is a little time-consuming 0.5s about 
 pic = base64.b64encode(pic)
 # print(path.replace("jpg" or "png" or "JPG","json"))
 if os.path.exists(path.replace("jpg","json")):
     with open(path.replace("jpg","json"), 'r') as f:
         line=json.load(f)
         try:
             json_file=eval(line)
         except:
             json_file=line
 else:
     json_file=None

 register_data = {
    'Pic': pic.decode(), 'Card_Json': json_file} 
 data = json.dumps(register_data) #python Data transfer json
 r = requests.post(url, data)
 
 para = json.loads(r.content)  # So does the value returned json
 print(para['answer'])
 print(para['idNumber'])

2. Server code

paras = json.loads(flask.request.get_data()) # Get json file （pic,json） And read 

# Take out the picture 
pic = paras['Pic']
user_image = base64.b64decode(pic)  # decode base64
img_array = np.fromstring(user_image, np.uint8) # Decode from the string arry Type data 
# cv2.imwrite('query.jpg', img_array)
img = cv2.imdecode(img_array, cv2.COLOR_BGR2RGB) # Decode and transfer rgb

# Take out json file 
json_handle = paras['Card_Json']
	try:
	    json_handle = eval(json_handle)
	except:
	    json_handle = json_handle

Here are some format transformations `.

import base64
import numpy as np
import requests as req
from PIL import Image
from io import BytesIO
import re
import cv2


# ???????url????????PIL Image????
def url_to_PIL_Image(img_url):
    response = req.get(img_url)
    image = Image.open(BytesIO(response.content))
    return image


# ?base64??????PIL Image????
def base64_to_PIL_Image(base64_str):
    byte_data = base64.b64decode(base64_str)
    image_data = BytesIO(byte_data)
    img = Image.open(image_data)
    return img


# ???base64_str
def change_img_as_base64(img_name):
    with open(img_name, 'rb') as f:
        return base64.b64encode(f.read())


# base64_str???
def change_base64_as_img(base64_str, result_img_path=None):
    img_data = base64.b64decode(base64_str)

    # ????
    if result_img_path is not None:
        with open(result_img_path, 'wb') as f:
            f.write(img_data)
    return img_data


# base64_str?opencv??
def change_base64_as_opencv(base64_str):
    img_data = base64.b64decode(base64_str)

    img_array = np.fromstring(img_data, np.uint8)  # ??np??
    img = cv2.imdecode(img_array, cv2.COLOR_BGR2RGB)  # ??Opencv??

    return img

In the later work, I will slowly make supplements ......