Node.js 多模态图像描述服务 调用siliconflow：现代 JavaScript 实践

Node.js 多模态图像描述服务：现代 JavaScript 实践

项目背景

本项目使用 Node.js 和 TypeScript 实现一个高性能的图像描述微服务，展示 JavaScript 在多模态 AI 应用中的强大能力。

技术栈

• Node.js
• TypeScript
• Express.js
• OpenAI API
• dotenv
• RxJS (可选，用于响应式编程)

项目初始化

# 创建项目目录
mkdir image-description-service
cd image-description-service

# 初始化项目
npm init -y
npm install typescript ts-node @types/node
npm install express dotenv openai
npm install -D @types/express

# 初始化 TypeScript 配置
npx tsc --init

环境配置 (.env)

# SiliconFlow API 配置
SILICONFLOW_API_KEY=sk-*******************************************
SILICONFLOW_BASE_URL=https://api.siliconflow.cn/v1

核心实现

1. 类型定义 (types.ts)

export interface ImageDescriptionRequest {
  imageUrl: string;
  language?: string;
  model?: string;
}

export interface ImageDescriptionResponse {
  description: string;
  chunks: string[];
  metadata: {
    processingTime: number;
    model: string;
  };
}

2. 服务实现 (imageDescriptionService.ts)

import OpenAI from 'openai';
import dotenv from 'dotenv';
import { 
  ImageDescriptionRequest, 
  ImageDescriptionResponse 
} from './types';

dotenv.config();

export class ImageDescriptionService {
  private openai: OpenAI;

  constructor() {
    this.openai = new OpenAI({
      apiKey: process.env.SILICONFLOW_API_KEY,
      baseURL: process.env.SILICONFLOW_BASE_URL
    });
  }

  async describeImage(
    request: ImageDescriptionRequest
  ): Promise<ImageDescriptionResponse> {
    const startTime = Date.now();

    try {
      const response = await this.openai.chat.completions.create({
        model: request.model || "Qwen/Qwen2-VL-72B-Instruct",
        messages: [
          {
            role: "user",
            content: [
              {
                type: "image_url",
                image_url: { url: request.imageUrl }
              },
              {
                type: "text",
                text: `用${request.language || '中文'}描述这张图片`
              }
            ]
          }
        ],
        stream: true
      });

      const chunks: string[] = [];
      let fullDescription = '';

      for await (const chunk of response) {
        const content = chunk.choices[0]?.delta?.content || '';
        if (content) {
          chunks.push(content);
          fullDescription += content;
        }
      }

      return {
        description: fullDescription,
        chunks,
        metadata: {
          processingTime: Date.now() - startTime,
          model: request.model || "Qwen/Qwen2-VL-72B-Instruct"
        }
      };
    } catch (error) {
      console.error('Image description error:', error);
      throw new Error('Failed to describe image');
    }
  }
}

3. Express 路由 (app.ts)

import express from 'express';
import { ImageDescriptionService } from './imageDescriptionService';

const app = express();
const port = process.env.PORT || 3000;
const descriptionService = new ImageDescriptionService();

app.use(express.json());

app.post('/describe-image', async (req, res) => {
  try {
    const { imageUrl, language, model } = req.body;
    const result = await descriptionService.describeImage({
      imageUrl, 
      language, 
      model
    });
    res.json(result);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.listen(port, () => {
  console.log(`服务运行在 http://localhost:${port}`);
});

4. 客户端调用示例 (client.ts)

import axios from 'axios';

async function describeImage() {
  try {
    const response = await axios.post('http://localhost:3000/describe-image', {
      imageUrl: 'https://sf-maas-uat-prod.oss-cn-shanghai.aliyuncs.com/dog.png',
      language: '中文'
    });

    console.log('图像描述:', response.data.description);
    console.log('处理时间:', response.data.metadata.processingTime, 'ms');
  } catch (error) {
    console.error('调用失败:', error);
  }
}

describeImage();

部署与扩展

Docker 容器化

FROM node:16-alpine
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
EXPOSE 3000
CMD ["npm", "start"]

性能优化

1. 缓存响应
2. 连接池
3. 限流
4. 异步处理

监控与日志

• Winston 日志
• Prometheus 指标
• OpenTelemetry 追踪

安全最佳实践

• 输入验证
• 速率限制
• 错误处理
• 敏感信息保护

立即体验

快来体验 siliconflow 图像描述服务：https://cloud.siliconflow.cn/i/vnCCfVaQ

快来体验 siliconflow 图像描述服务：https://cloud.siliconflow.cn/i/vnCCfVaQ

快来体验 siliconflow 图像描述服务：https://cloud.siliconflow.cn/i/vnCCfVaQ