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微信小程式前端如何呼叫python後端的模型詳解

2022-04-21 13:00:15

需求:

小程式端拍照呼叫python訓練好的圖片分類模型。實現圖片分類識別的功能。

微信小程式端:

重點在chooseImage函數中,根據圖片路徑獲取到圖片傳遞給flask的url;

Page({
    data: {
        SHOW_TOP: true,
        canRecordStart: false,
    },
    data: {
        tempFilePaths:'',
        sourceType: ['camera', 'album']
      },
    isSpeaking: false,
    accessToken: "",
    onLoad: function (options) {
        
        console.log("onLoad!");
        this.setHeader();
        var that=this
        wx.showShareMenu({
            withShareTicket: true //要求小程式返回分享目標資訊
        });
        var isShowed = wx.getStorageSync("tip");
        if (isShowed != 1) {
            setTimeout(() => {
                this.setData({
                    SHOW_TOP: false
                })
                wx.setStorageSync("tip", 1)
            }, 3 * 1000)
        } else {
            this.setData({
                SHOW_TOP: false
            })
        };
    },
    },
    
 //頭像點選處理事件,使用wx.showActionSheet()呼叫選單欄
 buttonclick: function () {
    const that = this
    wx.showActionSheet({
      itemList: ['拍照', '相簿'],
      itemColor: '',
      //成功時回撥
      success: function (res) {
        if (!res.cancel) {
          /*
           res.tapIndex返回使用者點選的按鈕序號,從上到下的順序,從0開始
           比如使用者點選本例中的拍照就返回0,相簿就返回1
           我們res.tapIndex的值傳給chooseImage()
          */
          that.chooseImage(res.tapIndex)
        }
      },
      
setHeader(){
    const tempFilePaths = wx.getStorageSync('tempFilePaths');
    if (tempFilePaths) {
      this.setData({
        tempFilePaths: tempFilePaths
      })
    } else {
      this.setData({
        tempFilePaths: '/images/camera.png'
      })
    }
  },

  chooseImage(tapIndex) {
    const checkeddata = true
    const that = this
    wx.chooseImage({
    //count表示一次可以選擇多少照片
      count: 1,
      //sizeType所選的圖片的尺寸,original原圖,compressed壓縮圖
      sizeType: ['original', 'compressed'],
      //如果sourceType為camera則呼叫攝像頭,為album時呼叫相簿
      sourceType: [that.data.sourceType[tapIndex]],
      success(res) {
        // tempFilePath可以作為img標籤的src屬性顯示圖片
        console.log(res);
        const tempFilePaths = res.tempFilePaths
        //將選擇到的圖片快取到本地storage中
        wx.setStorageSync('tempFilePaths', tempFilePaths)
        /*
		由於在我們選擇圖片後圖片只是儲存到storage中,所以我們需要呼叫一次   	        setHeader()方法來使頁面上的頭像更新
		*/
        that.setHeader();
        // wx.showToast({
        //   title: '設定成功',
        //   icon: 'none',
        // //   duration: 2000
        // })
        wx.showLoading({
            title: '識別中...',
        })
        
        var team_image = wx.getFileSystemManager().readFileSync(res.tempFilePaths[0], "base64")
        wx.request({
          url: 'http://127.0.0.1:5000/upload', //API地址,upload是我給路由起的名字,參照下面的python程式碼
                     method: "POST",
          header: {
                     'content-type': "application/x-www-form-urlencoded",
                    },
          data: {image: team_image},//將資料傳給後端
     
        success: function (res) {
            console.log(res.data);  //控制檯輸出返回資料  
            wx.hideLoading()
            wx.showModal({

                title: '識別結果', 
                confirmText: "識別正確",
                cancelText:"識別錯誤",
                content: res.data, 
                success: function(res) { 
                if (res.confirm) {
                console.log('識別正確')
                } else if (res.cancel) {
                console.log('重新識別')
                }
                }
                })     
          }
        })
      }
    })
  },
});

flask端:

將圖片裁剪,填充,呼叫自己訓練儲存最優的模型,用softmax處理結果矩陣,最後得到預測種類

# coding=utf-8
from flask import Flask, render_template, request, jsonify
from werkzeug.utils import secure_filename
from datetime import timedelta
from flask import Flask, render_template, request
import torchvision.transforms as transforms
from PIL import Image
from torchvision import models
import os
import torch
import json
import numpy as np
import torch.nn as nn
import matplotlib.pyplot as plt
import base64

app = Flask(__name__)

def softmax(x):
    exp_x = np.exp(x)
    softmax_x = exp_x / np.sum(exp_x, 0)
    return softmax_x

with open('dir_label.txt', 'r', encoding='utf-8') as f:
    labels = f.readlines()
    print("oldlabels:",labels)
    labels = list(map(lambda x: x.strip().split('t'), labels))
    print("newlabels:",labels)

def padding_black(img):
    w, h = img.size

    scale = 224. / max(w, h)
    img_fg = img.resize([int(x) for x in [w * scale, h * scale]])

    size_fg = img_fg.size
    size_bg = 224

    img_bg = Image.new("RGB", (size_bg, size_bg))

    img_bg.paste(img_fg, ((size_bg - size_fg[0]) // 2,
                              (size_bg - size_fg[1]) // 2))

    img = img_bg
    return img
# 輸出
@app.route('/')
def hello_world():
    return 'Hello World!'

# 設定允許的檔案格式
ALLOWED_EXTENSIONS = set(['png', 'jpg', 'JPG', 'PNG', 'bmp'])
def allowed_file(filename):
    return '.' in filename and filename.rsplit('.', 1)[1] in ALLOWED_EXTENSIONS

# 設定靜態檔案快取過期時間
app.send_file_max_age_default = timedelta(seconds=1)

# 新增路由
@app.route('/upload', methods=['POST', 'GET'])
def upload():
    if request.method == 'POST':
        # 通過file標籤獲取檔案
        team_image = base64.b64decode(request.form.get("image"))  # 隊base64進行解碼還原。
        with open("static/111111.jpg", "wb") as f:
            f.write(team_image)
        image = Image.open("static/111111.jpg")
        # image = Image.open('laji.jpg')
        image = image.convert('RGB')
        image = padding_black(image)
        transform1 = transforms.Compose([
            transforms.Resize(224),
            transforms.ToTensor(),
        ])
        image = transform1(image)
        image = image.unsqueeze(0)
        # image = torch.unsqueeze(image, dim=0).float()
        print(image.shape)
        model = models.resnet50(pretrained=False)
        fc_inputs = model.fc.in_features
        model.fc = nn.Linear(fc_inputs, 214)
        # model = model.cuda()
        # 載入訓練好的模型
        checkpoint = torch.load('model_best_checkpoint_resnet50.pth.tar')
        model.load_state_dict(checkpoint['state_dict'])
        model.eval()

        src = image.numpy()
        src = src.reshape(3, 224, 224)
        src = np.transpose(src, (1, 2, 0))
        # image = image.cuda()
        # label = label.cuda()
        pred = model(image)
        pred = pred.data.cpu().numpy()[0]

        score = softmax(pred)
        pred_id = np.argmax(score)

        plt.imshow(src)
        print('預測結果:', labels[pred_id][0])
        # return labels[pred_id][0];
        return json.dumps(labels[pred_id][0], ensure_ascii=False)//將預測結果傳回給前端
        # plt.show()
    #     return render_template('upload_ok.html')
    #     重新返回上傳介面
    # return render_template('upload.html')

if __name__ == '__main__':
    app.run(debug=False)

大致的效果:

但是在手機上測試的話,wx.request{}裡的url的域名不規範,不能出現這種埠號,目前還在想解決辦法,有知道的大佬還望告知。

總結

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