假设你正在使用@aws-sdk/client-s3，我已经实现了一个类似的例子，使用下面的代码从我的S3 bucket中获取图像：

const AWS = require('aws-sdk');
//*/ get reference to S3 client 
var s3 = new AWS.S3();
exports.handler = (event, context, callback) => {
    var params = {
      "Bucket": "your-bucket-name",
      "Key": "your-key"
    };
    s3.getObject(params, function(err, data){
       if(err) {
           callback(err, null);
       } else {
           let base64String= data.Body.toString('base64');
           let src = "data:image/jpeg;base64,"+base64String;
           
           let response = {
             "statusCode": 200,
             "base64image": base64String
           };

           callback(null, response);
       }
    });
    
};