PowerShell で FaceAPI に投げてみる ref: https://qiita.com/rnakamuramartiny/items/48af81533a05e0817914

FaceAPI_Detect_Post.ps1

$Face_API_KEY = '<FaceAPI Key>'
$URL = 'https://japaneast.api.cognitive.microsoft.com/face/v1.0/detect?returnFaceId=true&returnFaceLandmarks=true&returnFaceAttributes=age,gender,smile,facialHair,headPose,glasses,emotion,hair,makeup,accessories,blur,exposure,noise'
$image = '<FaceAPIに投げるファイルのフルパス>'
$headers = @{ 
    'Ocp-Apim-Subscription-Key' = $Face_API_KEY
    'Accept' = 'application/json'
    'Content-Type' = 'application/octet-stream'
}

$result = Invoke-RestMethod `
    -Uri $URL `
    -Method Post `
    -Headers $headers `
    -InFile $image

$result_ps = ($result | ConvertFrom-Json)

file1.txt

faceId         : 
faceRectangle  : @{top=337; left=746; width=318; height=318}
faceLandmarks  : @{pupilLeft=; pupilRight=; noseTip=; mouthLeft=; mouthRight=; eyebrowLeftOuter=; eyebrowLeftInner=; ey
                 eLeftOuter=; eyeLeftTop=; eyeLeftBottom=; eyeLeftInner=; eyebrowRightInner=; eyebrowRightOuter=; eyeRi
                 ghtInner=; eyeRightTop=; eyeRightBottom=; eyeRightOuter=; noseRootLeft=; noseRootRight=; noseLeftAlarT
                 op=; noseRightAlarTop=; noseLeftAlarOutTip=; noseRightAlarOutTip=; upperLipTop=; upperLipBottom=; unde
                 rLipTop=; underLipBottom=}
faceAttributes : @{smile=0.743; headPose=; gender=female; age=21.0; facialHair=; glasses=NoGlasses; emotion=; blur=; ex
                 posure=; noise=; makeup=; accessories=System.Object[]; hair=}

file3.txt

($result_ps.faceAttributes.hair.hairColor | `
 Sort-Object -Property confidence -Descending | `
 Select-Object -First 1).Color