GoogleCloudVisionAPI

main.go

package main

import(
	"golang.org/x/net/context"
	"golang.org/x/oauth2/google"

	"google.golang.org/api/vision/v1"
	"io/ioutil"
	"log"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"io"
	"encoding/binary"
	"crypto/rand"
	"strconv"
)

func main() {
	//設定ファイル読み込み
	confFile, err := ioutil.ReadFile("resources/google_credentials.json")
	if err != nil{
		log.Fatalln("failed to read configuration file" ,err)
	}

	//画像ファイル読み込み
	localPath, err := ImgFileDownload("http://www.skyarc.co.jp/assets_c/2016/02/interview_sasakura_s-thumb-260x260-7537.png")
	imgData, err := ioutil.ReadFile(localPath)
	if err != nil{
		log.Fatalln("failed to read image file" ,err)
	}

	cfg, err := google.JWTConfigFromJSON([]byte(confFile), vision.CloudPlatformScope)
	client := cfg.Client(context.Background())

	svc, err := vision.New(client)
	enc := base64.StdEncoding.EncodeToString([]byte(imgData))
	img := &vision.Image{Content: enc}

	// Possible values:
	//   "TYPE_UNSPECIFIED" - Unspecified feature type.
	//   "FACE_DETECTION" - Run face detection.
	//   "LANDMARK_DETECTION" - Run landmark detection.
	//   "LOGO_DETECTION" - Run logo detection.
	//   "LABEL_DETECTION" - Run label detection.
	//   "TEXT_DETECTION" - Run OCR.
	//   "SAFE_SEARCH_DETECTION" - Run various computer vision models to
	//   "IMAGE_PROPERTIES" - compute image safe-search properties.
	feature := &vision.Feature{
		Type:       "FACE_DETECTION",
		MaxResults: 5,
	}

	req := &vision.AnnotateImageRequest{
		Image:    img,
		Features: []*vision.Feature{feature},
	}

	batch := &vision.BatchAnnotateImagesRequest{
		Requests: []*vision.AnnotateImageRequest{req},
	}
	res, err := svc.Images.Annotate(batch).Do()

	body, err := json.MarshalIndent(res.Responses[0], "", "\t")
	fmt.Println(string(body))
}


func ImgFileDownload(url string) (path string, err error) {
	imgFilePath := "imgs/img_" + Random() + ".jpg"

	response, err := http.Get(url)
	if err != nil {
		log.Fatalln("failed to get image file" ,err)
	}

	defer response.Body.Close()

	file, err := os.Create(imgFilePath)
	if err != nil {
		log.Fatalln("failed to create image file" ,err)
	}
	defer file.Close()

	io.Copy(file, response.Body)
	return imgFilePath, err
}

func Random() string {
	var n uint64
	binary.Read(rand.Reader, binary.LittleEndian, &n)
	return strconv.FormatUint(n, 36)
}