Tcl
Tcl
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 Tcl Downloads
load ./chilkat.dll
set success 0
set rest [new_CkRest]
set authAws [new_CkAuthAws]
CkAuthAws_put_AccessKey $authAws "AWS_ACCESS_KEY"
CkAuthAws_put_SecretKey $authAws "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.)
CkAuthAws_put_Region $authAws "us-west-2"
CkAuthAws_put_ServiceName $authAws "rekognition"
# SetAuthAws causes Chilkat to automatically add the following headers: Authorization, X-Amz-Date
CkRest_SetAuthAws $rest $authAws
# URL: https://rekognition.us-west-2.amazonaws.com/
set bTls 1
set port 443
set bAutoReconnect 1
# Don't forget to change the region domain (us-west-2.amazonaws.com) to your particular region.
set success [CkRest_Connect $rest "rekognition.us-west-2.amazonaws.com" $port $bTls $bAutoReconnect]
if {$success != 1} then {
puts "ConnectFailReason: [CkRest_get_ConnectFailReason $rest]"
puts [CkRest_lastErrorText $rest]
delete_CkRest $rest
delete_CkAuthAws $authAws
exit
}
# 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.
set bdJpg [new_CkBinData]
set success [CkBinData_LoadFile $bdJpg "qa_data/jpg/monday_keep_smiling.jpg"]
if {$success != 1} then {
puts "Failed to load the input JPG file."
delete_CkRest $rest
delete_CkAuthAws $authAws
delete_CkBinData $bdJpg
exit
}
# 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:
# 
# 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.
set sbJpg [new_CkStringBuilder]
CkBinData_GetEncodedSb $bdJpg "base64" $sbJpg
set json [new_CkJsonObject]
CkJsonObject_UpdateSb $json "Image.Bytes" $sbJpg
CkRest_AddHeader $rest "Content-Type" "application/x-amz-json-1.1"
CkRest_AddHeader $rest "X-Amz-Target" "RekognitionService.DetectText"
set sbRequestBody [new_CkStringBuilder]
CkJsonObject_EmitSb $json $sbRequestBody
set sbResponseBody [new_CkStringBuilder]
set success [CkRest_FullRequestSb $rest "POST" "/" $sbRequestBody $sbResponseBody]
if {$success != 1} then {
puts [CkRest_lastErrorText $rest]
delete_CkRest $rest
delete_CkAuthAws $authAws
delete_CkBinData $bdJpg
delete_CkStringBuilder $sbJpg
delete_CkJsonObject $json
delete_CkStringBuilder $sbRequestBody
delete_CkStringBuilder $sbResponseBody
exit
}
set respStatusCode [CkRest_get_ResponseStatusCode $rest]
puts "response status code = $respStatusCode"
if {$respStatusCode >= 400} then {
puts "Response Status Code = $respStatusCode"
puts "Response Header:"
puts [CkRest_responseHeader $rest]
puts "Response Body:"
puts [CkStringBuilder_getAsString $sbResponseBody]
delete_CkRest $rest
delete_CkAuthAws $authAws
delete_CkBinData $bdJpg
delete_CkStringBuilder $sbJpg
delete_CkJsonObject $json
delete_CkStringBuilder $sbRequestBody
delete_CkStringBuilder $sbResponseBody
exit
}
set jResp [new_CkJsonObject]
CkJsonObject_LoadSb $jResp $sbResponseBody
CkJsonObject_put_EmitCompact $jResp 0
puts [CkJsonObject_emit $jResp]
# 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
set TextModelVersion [CkJsonObject_stringOf $jResp "TextModelVersion"]
set i 0
set count_i [CkJsonObject_SizeOfArray $jResp "TextDetections"]
while {$i < $count_i} {
CkJsonObject_put_I $jResp $i
set Confidence [CkJsonObject_stringOf $jResp "TextDetections[i].Confidence"]
set DetectedText [CkJsonObject_stringOf $jResp "TextDetections[i].DetectedText"]
set GeometryBoundingBoxHeight [CkJsonObject_stringOf $jResp "TextDetections[i].Geometry.BoundingBox.Height"]
set GeometryBoundingBoxLeft [CkJsonObject_stringOf $jResp "TextDetections[i].Geometry.BoundingBox.Left"]
set GeometryBoundingBoxTop [CkJsonObject_stringOf $jResp "TextDetections[i].Geometry.BoundingBox.Top"]
set GeometryBoundingBoxWidth [CkJsonObject_stringOf $jResp "TextDetections[i].Geometry.BoundingBox.Width"]
set Id [CkJsonObject_IntOf $jResp "TextDetections[i].Id"]
set v_Type [CkJsonObject_stringOf $jResp "TextDetections[i].Type"]
set ParentId [CkJsonObject_IntOf $jResp "TextDetections[i].ParentId"]
set j 0
set count_j [CkJsonObject_SizeOfArray $jResp "TextDetections[i].Geometry.Polygon"]
while {$j < $count_j} {
CkJsonObject_put_J $jResp $j
set X [CkJsonObject_stringOf $jResp "TextDetections[i].Geometry.Polygon[j].X"]
set Y [CkJsonObject_stringOf $jResp "TextDetections[i].Geometry.Polygon[j].Y"]
set j [expr $j + 1]
}
set i [expr $i + 1]
}
delete_CkRest $rest
delete_CkAuthAws $authAws
delete_CkBinData $bdJpg
delete_CkStringBuilder $sbJpg
delete_CkJsonObject $json
delete_CkStringBuilder $sbRequestBody
delete_CkStringBuilder $sbResponseBody
delete_CkJsonObject $jResp