(PowerShell) Google Cloud Vision Text Detection

Demonstrates calling the Google Cloud Vision for text detection (performs Optical Character Recognition). "Detects and extracts text within an image with support for a broad range of languages. It also features automatic language identification." See https://cloud.google.com/vision/docs/detecting-text

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

$success = $false

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# Build the following request:

# {
#   "requests": [
#     {
#       "image": {
#         "content": "/9j/7QBEUGhvdG9zaG9...base64-encoded-image-content...fXNWzvDEeYxxxzj/Coa6Bax//Z"
#       },
#       "features": [
#         {
#           "type": "TEXT_DETECTION"
#         }
#       ]
#     }
#   ]
# }

# Use this online tool to generate the code from sample JSON: 
# Generate Code to Create JSON

# Load an image file.
$imageData = New-Object Chilkat.BinData
# This image file contains some text...
$success = $imageData.LoadFile("qa_data/jpg/text.jpg")
if ($success -ne $true) {
    $("Failed to load image file.")
    exit
}

# Create the above JSON.
$json = New-Object Chilkat.JsonObject
$json.UpdateBd("requests[0].image.content","base64",$imageData)
$json.UpdateString("requests[0].features[0].type","TEXT_DETECTION")

# Send the following POST with the HTTP request body containing the above JSON.
# POST https://vision.googleapis.com/v1/images:annotate?key=YOUR_API_KEY

$http = New-Object Chilkat.Http
$http.SessionLogFilename = "c:/aaworkarea/sessionLog.txt"

$sb = New-Object Chilkat.StringBuilder
$url = "https://vision.googleapis.com/v1/images:annotate?key=YOUR_API_KEY"
$resp = New-Object Chilkat.HttpResponse
$success = $http.HttpJson("POST",$url,$json,"application/json",$resp)
if ($success -eq $false) {
    $($http.LastErrorText)
    exit
}

$("status = " + $resp.StatusCode)

# A 200 response status indicate success.
if ($resp.StatusCode -ne 200) {
    $($resp.BodyStr)
    $("Failed.")
    exit
}

$sbResponseBody = New-Object Chilkat.StringBuilder
$resp.GetBodySb($sbResponseBody)
$sbResponseBody.WriteFile("qa_output/textDetectResponse.json","utf-8",$false)
$json.LoadSb($sbResponseBody)

# The response is a JSON document like this:

# Use this online tool to generate parsing code from sample JSON: 
# Generate Parsing Code from JSON

# {
#   "responses": [
#     {
#       "textAnnotations": [
#         {
#           "locale": "en",
#           "description": "Chilkat is a cross-language, cross-platform\nAPl providing 90+ classes for many Internet\nprotocols, formats, and algorithms.\n",
#           "boundingPoly": {
#             "vertices": [
#               {
#                 "x": 17,
#                 "y": 14
#               },
# 	...
#             ]
#           }
#         ],
#         "text": "Chilkat is a cross-language, cross-platform\nAPl providing 90+ classes for many Internet\nprotocols, formats, and algorithms.\n"
#       }
#     }
#   ]
# }

# The parsing code generated from the online tool:

$json1 = New-Object Chilkat.JsonObject
$json2 = New-Object Chilkat.JsonObject

$i = 0
$count_i = $json.SizeOfArray("responses")
while ($i -lt $count_i) {
    $json.I = $i
    $fullTextAnnotationText = $json.StringOf("responses[i].fullTextAnnotation.text")
    $j = 0
    $count_j = $json.SizeOfArray("responses[i].textAnnotations")
    while ($j -lt $count_j) {
        $json.J = $j
        $locale = $json.StringOf("responses[i].textAnnotations[j].locale")
        $description = $json.StringOf("responses[i].textAnnotations[j].description")
        $k = 0
        $count_k = $json.SizeOfArray("responses[i].textAnnotations[j].boundingPoly.vertices")
        while ($k -lt $count_k) {
            $json.K = $k
            $x = $json.IntOf("responses[i].textAnnotations[j].boundingPoly.vertices[k].x")
            $y = $json.IntOf("responses[i].textAnnotations[j].boundingPoly.vertices[k].y")
            $k = $k + 1
        }

        $j = $j + 1
    }

    $j = 0
    $count_j = $json.SizeOfArray("responses[i].fullTextAnnotation.pages")
    while ($j -lt $count_j) {
        $json.J = $j
        $width = $json.IntOf("responses[i].fullTextAnnotation.pages[j].width")
        $height = $json.IntOf("responses[i].fullTextAnnotation.pages[j].height")
        $k = 0
        $count_k = $json.SizeOfArray("responses[i].fullTextAnnotation.pages[j].property.detectedLanguages")
        while ($k -lt $count_k) {
            $json.K = $k
            $languageCode = $json.StringOf("responses[i].fullTextAnnotation.pages[j].property.detectedLanguages[k].languageCode")
            $k = $k + 1
        }

        $k = 0
        $count_k = $json.SizeOfArray("responses[i].fullTextAnnotation.pages[j].blocks")
        while ($k -lt $count_k) {
            $json.K = $k
            $blockType = $json.StringOf("responses[i].fullTextAnnotation.pages[j].blocks[k].blockType")
            $json.ObjectOf2("responses[i].fullTextAnnotation.pages[j].blocks[k]",$json1)

            $i1 = 0
            $count_i1 = $json1.SizeOfArray("property.detectedLanguages")
            while ($i1 -lt $count_i1) {
                $json1.I = $i1
                $languageCode = $json1.StringOf("property.detectedLanguages[i].languageCode")
                $i1 = $i1 + 1
            }

            $json.ObjectOf2("responses[i].fullTextAnnotation.pages[j].blocks[k]",$json1)

            $i1 = 0
            $count_i1 = $json1.SizeOfArray("boundingBox.vertices")
            while ($i1 -lt $count_i1) {
                $json1.I = $i1
                $x = $json1.IntOf("boundingBox.vertices[i].x")
                $y = $json1.IntOf("boundingBox.vertices[i].y")
                $i1 = $i1 + 1
            }

            $json.ObjectOf2("responses[i].fullTextAnnotation.pages[j].blocks[k]",$json1)

            $i1 = 0
            $count_i1 = $json1.SizeOfArray("paragraphs")
            while ($i1 -lt $count_i1) {
                $json1.I = $i1
                $j1 = 0
                $count_j1 = $json1.SizeOfArray("paragraphs[i].property.detectedLanguages")
                while ($j1 -lt $count_j1) {
                    $json1.J = $j1
                    $languageCode = $json1.StringOf("paragraphs[i].property.detectedLanguages[j].languageCode")
                    $j1 = $j1 + 1
                }

                $j1 = 0
                $count_j1 = $json1.SizeOfArray("paragraphs[i].boundingBox.vertices")
                while ($j1 -lt $count_j1) {
                    $json1.J = $j1
                    $x = $json1.IntOf("paragraphs[i].boundingBox.vertices[j].x")
                    $y = $json1.IntOf("paragraphs[i].boundingBox.vertices[j].y")
                    $j1 = $j1 + 1
                }

                $j1 = 0
                $count_j1 = $json1.SizeOfArray("paragraphs[i].words")
                while ($j1 -lt $count_j1) {
                    $json1.J = $j1
                    $k1 = 0
                    $count_k1 = $json1.SizeOfArray("paragraphs[i].words[j].property.detectedLanguages")
                    while ($k1 -lt $count_k1) {
                        $json1.K = $k1
                        $languageCode = $json1.StringOf("paragraphs[i].words[j].property.detectedLanguages[k].languageCode")
                        $k1 = $k1 + 1
                    }

                    $k1 = 0
                    $count_k1 = $json1.SizeOfArray("paragraphs[i].words[j].boundingBox.vertices")
                    while ($k1 -lt $count_k1) {
                        $json1.K = $k1
                        $x = $json1.IntOf("paragraphs[i].words[j].boundingBox.vertices[k].x")
                        $y = $json1.IntOf("paragraphs[i].words[j].boundingBox.vertices[k].y")
                        $k1 = $k1 + 1
                    }

                    $k1 = 0
                    $count_k1 = $json1.SizeOfArray("paragraphs[i].words[j].symbols")
                    while ($k1 -lt $count_k1) {
                        $json1.K = $k1
                        $text = $json1.StringOf("paragraphs[i].words[j].symbols[k].text")
                        $propertyDetectedBreakType = $json1.StringOf("paragraphs[i].words[j].symbols[k].property.detectedBreak.type")
                        $json1.ObjectOf2("paragraphs[i].words[j].symbols[k]",$json2)

                        $i2 = 0
                        $count_i2 = $json2.SizeOfArray("property.detectedLanguages")
                        while ($i2 -lt $count_i2) {
                            $json2.I = $i2
                            $languageCode = $json2.StringOf("property.detectedLanguages[i].languageCode")
                            $i2 = $i2 + 1
                        }

                        $json1.ObjectOf2("paragraphs[i].words[j].symbols[k]",$json2)

                        $i2 = 0
                        $count_i2 = $json2.SizeOfArray("boundingBox.vertices")
                        while ($i2 -lt $count_i2) {
                            $json2.I = $i2
                            $x = $json2.IntOf("boundingBox.vertices[i].x")
                            $y = $json2.IntOf("boundingBox.vertices[i].y")
                            $i2 = $i2 + 1
                        }

                        $k1 = $k1 + 1
                    }

                    $j1 = $j1 + 1
                }

                $i1 = $i1 + 1
            }

            $k = $k + 1
        }

        $j = $j + 1
    }

    $i = $i + 1
}

$("Success.")