get-missing-alt-tags-from-vision-api.ps1

$visionUrl = 'https://westcentralus.api.cognitive.microsoft.com/vision/v1.0/analyze'
$visionApiKey = 'your-api-key' #go to: https://azure.microsoft.com/en-gb/try/cognitive-services/
$visionFeatures = 'Description,Tags,Categories'
$rootPathOfImages = "/sitecore/media library/Your Site"
$testMode = $false
$secondsToWaitOnLimitError = 60
$successCount = 0
$errorCount = 0
$errorList = ""
$date = Get-Date
$formattedDate =$date.tostring('dd-mmm-yyyy-hhmmss')
$csvOutputFilePath = "C:\Windows\Temp\Missing-Alt-Text-Report-$($formattedDate).csv"
$createCsv = $true
$csvResults = @()

# List of template ids to exclude from processing
$excludedTemplateIds = @(
    "{FE5DD826-48C6-436D-B87A-7C4210C7413B}", #media folder
    "{0603F166-35B8-469F-8123-E8D87BEDC171}", #pdf
    "{16692733-9A61-45E6-B0D4-4C0C06F8DD3C}", #doc
    "{7BB0411F-50CD-4C21-AD8F-1FCDE7C3AFFE}", #docx
    "{962B53C4-F93B-4DF9-9821-415C867B8903}", #unversioned file
    "{E76ADBDF-87D1-4FCB-BA71-274F7DBF5670}", #unversioned movie
    "{4F4A3A3B-239F-4988-98E1-DA3779749CBC}" #unversioned zip
)

# List of folder ids to exclude from processing
$excludedFolderIds = @(
    "{23FAF40D-6700-480C-BCAD-92E23F60634C}" #wffm folder
)

if($testMode){
    Write-Host -Foreground Yellow "Running in TEST MODE, no Alt Text will be set."
}
                    
Write-Host "Finding Images with Missing Alt Text in root folder: $($rootPathOfImages) ..."

cd $rootPathOfImages
$images = Get-ChildItem -Recurse . | Where-Object {
                                        ($excludedTemplateIds -notcontains $_.TemplateId) `
                                        -and ($excludedFolderIds -notcontains $_.ID) `
                                        -and ($excludedFolderIds -notcontains $_.Parent.ID) `
                                        -and ($excludedFolderIds -notcontains $_.Parent.Parent.ID) `
                                        -and ($excludedFolderIds -notcontains $_.Parent.Parent.Parent.ID) `
                                        -and ([string]::IsNullOrWhiteSpace($_.Fields["Alt"].Value)) `
                                    }

Write-Host -Foreground Green "$($images.Count) Images Found With Missing Alt Text"

$result = @()
$counter = 0
$mediaUrloptions = New-Object Sitecore.Resources.Media.MediaUrlOptions
$mediaUrloptions.Width = 1000
$mediaUrloptions.UseItemPath = 0

foreach ($image in $images)
{
    $counter+=1
    
    # Sitecore
    
    try{
        # Reading the binary of the image so that we could send it to the Computer Vision API
        Write-Host "Reading Image $($counter) of $($images.Count): $($image.ID) - $($image.Name) ...`n"
        $id = $image.ID
        $name = $image.Name
        $displayName = $image.Fields["__Display name"].Value
        $path = $image.ItemPath
        $success = $False
    
        $imageUrl = [Sitecore.Resources.Media.MediaManager]::GetMediaUrl($image, $mediaUrloptions)
        $url = $imageUrl -replace '/sitecore/shell', '' #fix to request image from published Site

        Write-Host "Downloading image: $url ...`n"

        $webClient = New-Object System.Net.WebClient
        $file = $webClient.DownloadData($url)
    }
    catch [System.Net.WebException]
    {
        $HttpStatusCode = $_.Exception.Response.StatusCode.value__
        $HttpStatusDescription = $_.Exception.Response.StatusDescription

        Write-Host -Foreground Red "Error Downloading Image: $($HttpStatusCode) - Http Status Description: $($HttpStatusDescription)"

        $errorCount +=1
        $errorList = $errorList + "$($id) - $($name) `n"
        continue
    }
    catch
    {
        Write-Host -Foreground Red "Error Downloading Image: $($id) - $($name) - Error Message: $($_.Exception.Message)"
        continue
    }

    # Computer Vision API
    
    do
    {
        try
        {
            if($file){
                Write-Host "Calling Endpoint: $($visionUrl)?visualFeatures=$($visionFeatures)&language=en"

                # Calling the Computer Vision API
                $response = Invoke-WebRequest `
                                 -Uri "$($visionUrl)?visualFeatures=$($visionFeatures)&language=en" `
                                 -Body $file `
                                 -ContentType "application/octet-stream" `
                                 -Headers @{"Ocp-Apim-Subscription-Key" = "$($visionApiKey)"} `
                                 -Method 'Post' `
                                 -ErrorAction Stop `
                                 -UseBasicParsing | ConvertFrom-Json

                # Tracking what image the response should be attached to
                $response | Add-Member -Name "id" `
                                       -MemberType NoteProperty `
                                       -Value "$($image.ID.ToShortID())"
                
                $altText = $response.description.captions[0].text
                Write-Host "Image Processed: $($image.Paths.FullPath)`n`n"
                
                if($altText){
                    
                    if($testMode){
                        Write-Host -Foreground Cyan "Alt Text Not set as in TEST MODE, but would be:" $altText
                    }
                    else 
                    {
                        # update Alt tag on image
                        $image.Editing.BeginEdit()
                        $image.Fields["Alt"].Value = $altText
                        $image.Editing.EndEdit()

                        Write-Host -Foreground Cyan "Alt Text Set To:" $altText
                        Write-Host "----------------------------------`n`n"
                    }
                    
                    $result += $response

                    $csvProperties = @{
                        ID = $id
                        Name = $name
                        DisplayName = $displayName
                        Path = $path
                        AltText = $altText
                    }

                    $csvResults += New-Object psobject -Property $csvProperties;

                    $success = $True

                    $successCount +=1

                }
                else{
                    Write-Host -Foreground Yellow "No Alt Text Returned For Image: $($id) - $($name)"
                    $errorCount +=1
                    $errorList = $errorList + "$($id) - $($name) `n"
                    break
                }
            }
            else{
                    Write-Host -Foreground Red "No Image Found In Sitecore For: $($id) - $($name)"
                    $errorCount +=1
                    $errorList = $errorList + "$($id) - $($name) `n"
                    break
                }
        }
        catch [System.Net.WebException]
        {
            $HttpStatusCode = $_.Exception.Response.StatusCode.value__
            $HttpStatusDescription = $_.Exception.Response.StatusDescription

            Write-Host -Foreground Red "Error Calling Computer Vision API: $($HttpStatusCode) - Http Status Description: $($HttpStatusDescription)"

            if($HttpStatusCode -eq "429"){
                Write-Host  -Foreground Magenta "Exceeded Computer Vision API limit. Waiting for $($secondsToWaitOnLimitError) seconds..."
                Start-Sleep -s $secondsToWaitOnLimitError
                Write-Host -Foreground Green "Resuming now..."
            }
            else{
                $errorCount +=1
                $errorList = $errorList + "$($id) - $($name) `n"
                break
            }
        }
        catch
        {
                Write-Host -Foreground Red "Error processing Image: $($id) - $($name) - Error Message: $($_.Exception.Message)"
                break
        }
    }
    while ($success -ne $True)
}

if($testMode){
    Write-Host -Foreground Yellow "TEST MODE complete."
}
Write-Host -Foreground Green "$($successCount) Images Successfully Processed"
Write-Host "$($errorCount) Errors Processing Images"

if($errorCount -gt 0){
    Write-Host -Foreground Red "Errors List"
    Write-Host -Foreground Red "-----------------------------"
    Write-Host -Foreground Red $errorList
}

if($createCsv -and $successCount -gt 0){
    Write-Host "Saving Report of Alt Text to: ${csvOutputFilePath}"
    $csvResults | Select-Object ID,Name,DisplayName,Path,AltText | Export-Csv -notypeinformation -Path $csvOutputFilePath
}

#Write-Host ($result | ConvertTo-Json -Depth 5)