Image Processing Serverless with AWS Step Functions

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Image Processing Serverless with AWS Step Functions

As mentioned in the last article, We will follow the AWS workshop https://www.image-processing.serverlessworkshops.io/ to build a real AWS Serverless Project with AWS Step Functions.

This is the structure that we gonna build.

Follow the workshop, The main sam.yaml file located in here: https://gist.githubusercontent.com/khoa-le/98855ac969c8b3c7eb3dfa2cce68de12/raw/ac1373b6b35a678450b47e727d7741a54c5c8ed1/sam_220615.yaml

You can download and take a look on those configuration and to apply successfully you should choose the region us-east-1 because the yaml file for us-east-1 configured.

The Cloudformation created look likes:

The Step functions after finished the workshop

The Step functions definition

Here is the khoale-step-module-resources-FaceDetectionFunction lambda

1const util = require('util')
2const AWS = require('aws-sdk')
3const rekognition = new AWS.Rekognition()
4
5exports.handler = (event, context, callback) => {
6  console.log('Reading input from event:\n', util.inspect(event, {depth: 5}))
7
8  const srcBucket = event.s3Bucket
9  // Object key may have spaces or unicode non-ASCII characters.
10  const srcKey = decodeURIComponent(event.s3Key.replace(/\+/g, ' '))
11
12  var params = {
13    Image: {
14      S3Object: {
15        Bucket: srcBucket,
16        Name: srcKey,
17      },
18    },
19    Attributes: ['ALL'],
20  }
21
22  rekognition
23    .detectFaces(params)
24    .promise()
25    .then(data => {
26      console.log(
27        'Detection result from rekognition:\n',
28        util.inspect(data, {depth: 5}),
29      )
30      if (data.FaceDetails.length != 1) {
31        callback(
32          new PhotoDoesNotMeetRequirementError(
33            'Detected ' + data.FaceDetails.length + ' faces in the photo.',
34          ),
35        )
36      }
37      if (data.FaceDetails[0].Sunglasses.Value === true) {
38        callback(
39          new PhotoDoesNotMeetRequirementError('Face is wearing sunglasses'),
40        )
41      }
42      var detectedFaceDetails = data.FaceDetails[0]
43
44      // remove some fields not used in further processing to de-clutter the output.
45      delete detectedFaceDetails['Landmarks']
46
47      callback(null, detectedFaceDetails)
48    })
49    .catch(err => {
50      console.log(err)
51      if (err.code === 'ImageTooLargeException') {
52        callback(new PhotoDoesNotMeetRequirementError(err.message))
53      }
54      if (err.code === 'InvalidImageFormatException') {
55        callback(
56          new PhotoDoesNotMeetRequirementError(
57            'Unsupported image file format. Only JPEG or PNG is supported',
58          ),
59        )
60      }
61      callback(err)
62    })
63}
64
65function PhotoDoesNotMeetRequirementError(message) {
66  this.name = 'PhotoDoesNotMeetRequirementError'
67  this.message = message
68}
69PhotoDoesNotMeetRequirementError.prototype = new Error()

Here is the khoale-step-module-resources-FaceSearchFunction lambda

1const util = require('util')
2const AWS = require('aws-sdk')
3const rekognition = new AWS.Rekognition()
4
5exports.handler = (event, context, callback) => {
6  console.log('Reading input from event:\n', util.inspect(event, {depth: 5}))
7
8  const srcBucket = event.s3Bucket
9  // Object key may have spaces or unicode non-ASCII characters.
10  const srcKey = decodeURIComponent(event.s3Key.replace(/\+/g, ' '))
11
12  var params = {
13    CollectionId: process.env.REKOGNITION_COLLECTION_ID,
14    Image: {
15      S3Object: {
16        Bucket: srcBucket,
17        Name: srcKey,
18      },
19    },
20    FaceMatchThreshold: 70.0,
21    MaxFaces: 3,
22  }
23  rekognition
24    .searchFacesByImage(params)
25    .promise()
26    .then(data => {
27      if (data.FaceMatches.length > 0) {
28        callback(new FaceAlreadyExistsError())
29      } else {
30        callback(null, null)
31      }
32    })
33    .catch(err => {
34      callback(err)
35    })
36}
37
38function FaceAlreadyExistsError() {
39  this.name = 'FaceAlreadyExistsError'
40  this.message = 'Face in the picture is already in the system. '
41}
42FaceAlreadyExistsError.prototype = new Error()

Here is the khoale-step-module-resources-ThumbnailFunction lambda

1// dependencies
2const AWS = require('aws-sdk')
3const gm = require('gm').subClass({imageMagick: true}) // Enable ImageMagick integration.
4const util = require('util')
5const Promise = require('bluebird')
6Promise.promisifyAll(gm.prototype)
7
8// constants
9const MAX_WIDTH = process.env.MAX_WIDTH ? process.env.MAX_WIDTH : 250
10const MAX_HEIGHT = process.env.MAX_HEIGHT ? process.env.MAX_HEIGHT : 250
11
12const thumbnailBucket = process.env.THUMBNAIL_BUCKET
13
14// get reference to S3 client
15const s3 = new AWS.S3()
16
17exports.handler = (event, context, callback) => {
18  console.log('Reading input from event:\n', util.inspect(event, {depth: 5}))
19
20  // get the object from S3 first
21  const s3Bucket = event.s3Bucket
22  // Object key may have spaces or unicode non-ASCII characters.
23  const srcKey = decodeURIComponent(event.s3Key.replace(/\+/g, ' '))
24  const getObjectPromise = s3
25    .getObject({
26      Bucket: s3Bucket,
27      Key: srcKey,
28    })
29    .promise()
30
31  // identify image metadata
32  const identifyPromise = new Promise(resolve => {
33    getObjectPromise
34      .then(getObjectResponse => {
35        console.log('success downloading from s3.')
36        gm(getObjectResponse.Body)
37          .identifyAsync()
38          .then(data => {
39            console.log(
40              'Identified metadata:\n',
41              util.inspect(data, {depth: 5}),
42            )
43            resolve(data)
44          })
45          .catch(err => {
46            callback(err)
47          })
48      })
49      .catch(err => {
50        callback(err)
51      })
52  })
53
54  // resize the image
55  var resizePromise = new Promise(resolve => {
56    getObjectPromise
57      .then(getObjectResponse => {
58        identifyPromise
59          .then(identified => {
60            const size = identified.size
61            const scalingFactor = Math.min(
62              MAX_WIDTH / size.width,
63              MAX_HEIGHT / size.height,
64            )
65            const width = scalingFactor * size.width
66            const height = scalingFactor * size.height
67            gm(getObjectResponse.Body)
68              .resize(width, height)
69              .toBuffer(identified.format, (err, buffer) => {
70                if (err) {
71                  console.error('failure resizing to ' + width + ' x ' + height)
72                  callback(err)
73                } else {
74                  console.log('success resizing to ' + width + ' x ' + height)
75                  resolve(buffer)
76                }
77              })
78          })
79          .catch(err => callback(err))
80      })
81      .catch(function (err) {
82        callback(err)
83      })
84  })
85
86  // upload the result image back to s3
87  const destKey = 'resized-' + srcKey
88
89  resizePromise
90    .then(buffer => {
91      identifyPromise
92        .then(identified => {
93          const s3PutParams = {
94            Bucket: thumbnailBucket,
95            Key: destKey,
96            ContentType: 'image/' + identified.format.toLowerCase(),
97          }
98
99          s3PutParams.Body = buffer
100          s3.upload(s3PutParams)
101            .promise()
102            .then(data => {
103              delete s3PutParams.Body
104              console.log('success uploading to s3:\n ', s3PutParams)
105              var thumbnailImage = {}
106              thumbnailImage.s3key = destKey
107              thumbnailImage.s3bucket = thumbnailBucket
108              callback(null, {thumbnail: thumbnailImage})
109            })
110            .catch(function (err) {
111              delete s3PutParams.Body
112              console.error('failure uploading to s3:\n ', s3PutParams)
113              callback(err)
114            })
115        })
116        .catch(err => {
117          callback(err)
118        })
119    })
120    .catch(function (err) {
121      callback(err)
122    })
123}

Here is the khoale-step-module-resources-IndexFaceFunction lambda

1const util = require('util')
2const AWS = require('aws-sdk')
3const rekognition = new AWS.Rekognition()
4
5exports.handler = (event, context, callback) => {
6  const srcBucket = event.s3Bucket
7  // Object key may have spaces or unicode non-ASCII characters.
8  const srcKey = decodeURIComponent(event.s3Key.replace(/\+/g, ' '))
9
10  var params = {
11    CollectionId: process.env.REKOGNITION_COLLECTION_ID,
12    DetectionAttributes: [],
13    ExternalImageId: event.userId,
14    Image: {
15      S3Object: {
16        Bucket: srcBucket,
17        Name: srcKey,
18      },
19    },
20  }
21  rekognition
22    .indexFaces(params)
23    .promise()
24    .then(data => {
25      callback(null, data['FaceRecords'][0]['Face'])
26    })
27    .catch(err => {
28      callback(err)
29    })
30}