API KEY를 Google Developers Console에서 생성

Google Developers Console

프로젝트 만들기

결제 방법 설정

Cloud Vision API 사용

API KEY 얻기

검증

확인할 이미지

샘플 프로그램

require 'base64'
require 'json'
require 'net/http'
require 'uri'
require 'open-uri'

VISION_API_URL = "https://vision.googleapis.com/v1/images:annotate"
API_KEY        = "Google Developers Consoleで作成したキー"
URL            = "#{VISION_API_URL}?key=#{API_KEY}"
INPUT_IMG_FILE = 'http://blog-imgs-42-origin.fc2.com/k/o/t/kotomona/20101125183059615.jpg'

begin
  uri           = URI.parse(URL)
  https         = Net::HTTP.new(uri.host, uri.port)
  https.use_ssl = true

  req                 = Net::HTTP::Post.new(uri.request_uri)
  req["Content-Type"] = "application/json"
  param               = {
    "requests" =>
    [
      {
        "image" =>
        {
          "content" => Base64.strict_encode64(open(INPUT_IMG_FILE).read)
        },
        "features" =>
        [
          {
            "type"       => "LABEL_DETECTION",
            "maxResults" => 10
          },
          {
            "type"       => "TEXT_DETECTION",
            "maxResults" => 10
          }
        ]
      }
    ]
  }
  req.body = param.to_json
  res      = https.request(req)

  case res
  when Net::HTTPSuccess
    puts res.body
  else
    res.error!
  end
rescue => e
  puts "error = #{e.message}"
end

응답

{
  "responses": [
    {
      "labelAnnotations": [
        {
          "mid": "/m/0215n",
          "description": "cartoon",
          "score": 0.93569827
        },
        {
          "mid": "/m/05qdh",
          "description": "painting",
          "score": 0.75862324
        },
        {
          "mid": "/m/0dgsmq8",
          "description": "artwork",
          "score": 0.71173751
        },
        {
          "mid": "/m/012h24",
          "description": "comics",
          "score": 0.63047028
        },
        {
          "mid": "/m/01kr8f",
          "description": "illustration",
          "score": 0.62665105
        }
      ],
      "textAnnotations": [
        {
          "locale": "ja",
          "description": "た\nC&as\nパスケが\nしたいです……\n",
          "boundingPoly": {
            "vertices": [
              {
                "x": 236,
                "y": 143
              },
              {
                "x": 395,
                "y": 143
              },
              {
                "x": 395,
                "y": 502
              },
              {
                "x": 236,
                "y": 502
              }
            ]
          }
        }
      ]
    }
  ]
}