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Ruby

Amazon Rekognition - Detect Text in an Image

See more Amazon Rekognition Examples

Detects text in the input image and converts it into machine-readable text. This example passes theimage as base64-encoded image bytes.

Chilkat Ruby Downloads

Ruby
require 'chilkat'

success = false

rest = Chilkat::CkRest.new()

authAws = Chilkat::CkAuthAws.new()
authAws.put_AccessKey("AWS_ACCESS_KEY")
authAws.put_SecretKey("AWS_SECRET_KEY")
#  Don't forget to change the region to your particular region. (Also make the same change in the call to Connect below.)
authAws.put_Region("us-west-2")
authAws.put_ServiceName("rekognition")
#  SetAuthAws causes Chilkat to automatically add the following headers: Authorization, X-Amz-Date
rest.SetAuthAws(authAws)

#  URL: https://rekognition.us-west-2.amazonaws.com/
bTls = true
port = 443
bAutoReconnect = true
#  Don't forget to change the region domain (us-west-2.amazonaws.com) to your particular region.
success = rest.Connect("rekognition.us-west-2.amazonaws.com",port,bTls,bAutoReconnect)
if (success != true)
    print "ConnectFailReason: " + rest.get_ConnectFailReason().to_s() + "\n";
    print rest.lastErrorText() + "\n";
    exit
end

#  Note: The above code does not need to be repeatedly called for each REST request.
#  The rest object can be setup once, and then many requests can be sent.  Chilkat will automatically
#  reconnect within a FullRequest* method as needed.  It is only the very first connection that is explicitly
#  made via the Connect method.

#  Load the JPG to be passed as base64 in the JSON.
bdJpg = Chilkat::CkBinData.new()
success = bdJpg.LoadFile("qa_data/jpg/monday_keep_smiling.jpg")
if (success != true)
    print "Failed to load the input JPG file." + "\n";
    exit
end

#  We wish to send the following JSON in the body of our HTTP request:

#  {
#    "Image": {
#        "Bytes": "base64_image_bytes"
#    }
#  }

#  Here is the image we used for testing:
#  image

#  Convert binary image bytes to base64.
#  Note: We are explicitly keeping the data inside Chilkat to avoid having to pass large strings
#  as arguments to function calls.  This is important for some programming languages.
sbJpg = Chilkat::CkStringBuilder.new()
bdJpg.GetEncodedSb("base64",sbJpg)

json = Chilkat::CkJsonObject.new()
json.UpdateSb("Image.Bytes",sbJpg)

rest.AddHeader("Content-Type","application/x-amz-json-1.1")
rest.AddHeader("X-Amz-Target","RekognitionService.DetectText")

sbRequestBody = Chilkat::CkStringBuilder.new()
json.EmitSb(sbRequestBody)
sbResponseBody = Chilkat::CkStringBuilder.new()
success = rest.FullRequestSb("POST","/",sbRequestBody,sbResponseBody)
if (success != true)
    print rest.lastErrorText() + "\n";
    exit
end

respStatusCode = rest.get_ResponseStatusCode()
print "response status code = " + respStatusCode.to_s() + "\n";

if (respStatusCode >= 400)
    print "Response Status Code = " + respStatusCode.to_s() + "\n";
    print "Response Header:" + "\n";
    print rest.responseHeader() + "\n";
    print "Response Body:" + "\n";
    print sbResponseBody.getAsString() + "\n";
    exit
end

jResp = Chilkat::CkJsonObject.new()
jResp.LoadSb(sbResponseBody)

jResp.put_EmitCompact(false)
print jResp.emit() + "\n";

#  Sample JSON response:
#  (Sample code for parsing the JSON response is shown below)

#  {
#    "TextDetections": [
#      {
#        "Confidence": 95.99308776855469,
#        "DetectedText": "( MONDAY IT'S",
#        "Geometry": {
#          "BoundingBox": {
#            "Height": 0.6399821043014526,
#            "Left": 0.219133198261261,
#            "Top": 0.08677978068590164,
#            "Width": 0.7433173656463623
#          },
#          "Polygon": [
#            {
#              "X": 0.219133198261261,
#              "Y": 0.3588336706161499
#            },
#            {
#              "X": 0.8984103798866272,
#              "Y": 0.08677978068590164
#            },
#            {
#              "X": 0.9624505639076233,
#              "Y": 0.4547080099582672
#            },
#            {
#              "X": 0.2831733524799347,
#              "Y": 0.7267619371414185
#            }
#          ]
#        },
#        "Id": 0,
#        "Type": "LINE"
#      },
#      {
#        "Confidence": 99.70352172851562,
#        "DetectedText": "but keep",
#        "Geometry": {
#          "BoundingBox": {
#            "Height": 0.09703556448221207,
#            "Left": 0.6335319876670837,
#            "Top": 0.5153074264526367,
#            "Width": 0.21070890128612518
#          },
#          "Polygon": [
#            {
#              "X": 0.6355597376823425,
#              "Y": 0.5153074264526367
#            },
#            {
#              "X": 0.8442409038543701,
#              "Y": 0.5266726613044739
#            },
#            {
#              "X": 0.8422132134437561,
#              "Y": 0.6123430132865906
#            },
#            {
#              "X": 0.6335319876670837,
#              "Y": 0.6009777784347534
#            }
#          ]
#        },
#        "Id": 1,
#        "Type": "LINE"
#      },
#      {
#        "Confidence": 99.92333984375,
#        "DetectedText": "Smiling",
#        "Geometry": {
#          "BoundingBox": {
#            "Height": 0.31578224897384644,
#            "Left": 0.5070608258247375,
#            "Top": 0.6086956262588501,
#            "Width": 0.4795433282852173
#          },
#          "Polygon": [
#            {
#              "X": 0.5070608258247375,
#              "Y": 0.6298336386680603
#            },
#            {
#              "X": 0.9808917045593262,
#              "Y": 0.6086956262588501
#            },
#            {
#              "X": 0.9866041541099548,
#              "Y": 0.9033399224281311
#            },
#            {
#              "X": 0.5127732157707214,
#              "Y": 0.9244779348373413
#            }
#          ]
#        },
#        "Id": 2,
#        "Type": "LINE"
#      },
#      {
#        "Confidence": 99.77294158935547,
#        "DetectedText": "IT'S",
#        "Geometry": {
#          "BoundingBox": {
#            "Height": 0.09903381764888763,
#            "Left": 0.668789803981781,
#            "Top": 0.17874395847320557,
#            "Width": 0.1449044644832611
#          },
#          "Polygon": [
#            {
#              "X": 0.668789803981781,
#              "Y": 0.17874395847320557
#            },
#            {
#              "X": 0.8136942386627197,
#              "Y": 0.17874395847320557
#            },
#            {
#              "X": 0.8136942386627197,
#              "Y": 0.2777777910232544
#            },
#            {
#              "X": 0.668789803981781,
#              "Y": 0.2777777910232544
#            }
#          ]
#        },
#        "Id": 5,
#        "ParentId": 0,
#        "Type": "WORD"
#      },
#      {
#        "Confidence": 98.44307708740234,
#        "DetectedText": "MONDAY",
#        "Geometry": {
#          "BoundingBox": {
#            "Height": 0.11112251877784729,
#            "Left": 0.5541401505470276,
#            "Top": 0.3526569902896881,
#            "Width": 0.39013487100601196
#          },
#          "Polygon": [
#            {
#              "X": 0.5541401505470276,
#              "Y": 0.3526569902896881
#            },
#            {
#              "X": 0.9442675113677979,
#              "Y": 0.3502415418624878
#            },
#            {
#              "X": 0.9458598494529724,
#              "Y": 0.4613526463508606
#            },
#            {
#              "X": 0.5541401505470276,
#              "Y": 0.4637681245803833
#            }
#          ]
#        },
#        "Id": 4,
#        "ParentId": 0,
#        "Type": "WORD"
#      },
#      {
#        "Confidence": 99.61898803710938,
#        "DetectedText": "but",
#        "Geometry": {
#          "BoundingBox": {
#            "Height": 0.06521739065647125,
#            "Left": 0.6353503465652466,
#            "Top": 0.5241546034812927,
#            "Width": 0.0843949019908905
#          },
#          "Polygon": [
#            {
#              "X": 0.6353503465652466,
#              "Y": 0.5241546034812927
#            },
#            {
#              "X": 0.7197452187538147,
#              "Y": 0.5241546034812927
#            },
#            {
#              "X": 0.7197452187538147,
#              "Y": 0.5893719792366028
#            },
#            {
#              "X": 0.6353503465652466,
#              "Y": 0.5893719792366028
#            }
#          ]
#        },
#        "Id": 6,
#        "ParentId": 1,
#        "Type": "WORD"
#      },
#      {
#        "Confidence": 99.78804779052734,
#        "DetectedText": "keep",
#        "Geometry": {
#          "BoundingBox": {
#            "Height": 0.07971014827489853,
#            "Left": 0.7308917045593262,
#            "Top": 0.5265700221061707,
#            "Width": 0.1114649698138237
#          },
#          "Polygon": [
#            {
#              "X": 0.7308917045593262,
#              "Y": 0.5265700221061707
#            },
#            {
#              "X": 0.8423566818237305,
#              "Y": 0.5265700221061707
#            },
#            {
#              "X": 0.8423566818237305,
#              "Y": 0.6062802076339722
#            },
#            {
#              "X": 0.7308917045593262,
#              "Y": 0.6062802076339722
#            }
#          ]
#        },
#        "Id": 7,
#        "ParentId": 1,
#        "Type": "WORD"
#      },
#      {
#        "Confidence": 89.76324462890625,
#        "DetectedText": "(",
#        "Geometry": {
#          "BoundingBox": {
#            "Height": 0.16401274502277374,
#            "Left": 0.27229300141334534,
#            "Top": 0.6642512083053589,
#            "Width": 0.2850286066532135
#          },
#          "Polygon": [
#            {
#              "X": 0.27229300141334534,
#              "Y": 0.6642512083053589
#            },
#            {
#              "X": 0.2707006335258484,
#              "Y": 0.37922704219818115
#            },
#            {
#              "X": 0.43471336364746094,
#              "Y": 0.37922704219818115
#            },
#            {
#              "X": 0.4363057315349579,
#              "Y": 0.6642512083053589
#            }
#          ]
#        },
#        "Id": 3,
#        "ParentId": 0,
#        "Type": "WORD"
#      },
#      {
#        "Confidence": 99.92333984375,
#        "DetectedText": "Smiling",
#        "Geometry": {
#          "BoundingBox": {
#            "Height": 0.294724702835083,
#            "Left": 0.5079618096351624,
#            "Top": 0.6304348111152649,
#            "Width": 0.4734293222427368
#          },
#          "Polygon": [
#            {
#              "X": 0.5079618096351624,
#              "Y": 0.6304348111152649
#            },
#            {
#              "X": 0.9808917045593262,
#              "Y": 0.6086956262588501
#            },
#            {
#              "X": 0.9856687784194946,
#              "Y": 0.9033816456794739
#            },
#            {
#              "X": 0.512738823890686,
#              "Y": 0.9227052927017212
#            }
#          ]
#        },
#        "Id": 8,
#        "ParentId": 2,
#        "Type": "WORD"
#      }
#    ],
#    "TextModelVersion": "3.0"
#  }
#  
#  

#  Sample code for parsing the JSON response...
#  Use the following online tool to generate parsing code from sample JSON:
#  Generate Parsing Code from JSON

TextModelVersion = jResp.stringOf("TextModelVersion")
i = 0
count_i = jResp.SizeOfArray("TextDetections")
while i < count_i
    jResp.put_I(i)
    Confidence = jResp.stringOf("TextDetections[i].Confidence")
    DetectedText = jResp.stringOf("TextDetections[i].DetectedText")
    GeometryBoundingBoxHeight = jResp.stringOf("TextDetections[i].Geometry.BoundingBox.Height")
    GeometryBoundingBoxLeft = jResp.stringOf("TextDetections[i].Geometry.BoundingBox.Left")
    GeometryBoundingBoxTop = jResp.stringOf("TextDetections[i].Geometry.BoundingBox.Top")
    GeometryBoundingBoxWidth = jResp.stringOf("TextDetections[i].Geometry.BoundingBox.Width")
    Id = jResp.IntOf("TextDetections[i].Id")
    v_Type = jResp.stringOf("TextDetections[i].Type")
    ParentId = jResp.IntOf("TextDetections[i].ParentId")
    j = 0
    count_j = jResp.SizeOfArray("TextDetections[i].Geometry.Polygon")
    while j < count_j
        jResp.put_J(j)
        X = jResp.stringOf("TextDetections[i].Geometry.Polygon[j].X")
        Y = jResp.stringOf("TextDetections[i].Geometry.Polygon[j].Y")
        j = j + 1
    end
    i = i + 1
end