s3-rekognition.js

const AWS = require('aws-sdk');

function getObject({ Bucket, Key }) {
  return new Promise((res, rej) => {
    const s3 = new AWS.S3();

    const params = {
      Bucket,
      Key,
    };
    s3.getObject(params, (err, data) => {
      if (err) {
        rej(err);
      } else {
        // @ts-ignore
        const ret = data.Body;
        res(ret);
      }
    });
  });
}

function detectFace({ Bytes }) {
  return new Promise((res, rej) => {
    const rekognition = new AWS.Rekognition();
    const params = {
      Image: {
        /* required */
        Bytes,
      },
      Attributes: ['ALL', 'DEFAULT'],
    };
    rekognition.detectFaces(params, (err, data) => {
      if (err) {
        rej(err);
      } else {
        res(data);
      }
    });
  });
}

function detectText({ Bytes }) {
  return new Promise((res, rej) => {
    const rekognition = new AWS.Rekognition();

    const params = {
      Image: {
        /* required */
        Bytes,
      },
    };
    rekognition.detectText(params, (err, data) => {
      if (err) {
        rej(err);
      } else {
        res(data);
      }
    });
  });
}

exports.handler = async (a, b, c) => {
  const Bucket = a.Records[0].s3.bucket.name;
  const Key = a.Records[0].s3.object.key;

  const Bytes = await getObject({ Bucket, Key });
  console.log('got data, l=', Bytes.length);

  const ret = await detectText({ Bytes });

  const lines = ret.TextDetections.filter(r => r.Type === 'LINE').map(
    r2 => r2.DetectedText,
  );
  console.log('ret=', JSON.stringify(lines, null, 2));
  const response = {
    statusCode: 200,
    body: JSON.stringify(ret, null, 2),
  };
  return response;
};