Google Cloud Vision (Golang)

test.go

package main

import (
	"fmt"
	"os"
	"bufio"
	"encoding/base64"
	"encoding/json"
	"net/http"
	"bytes"
	"io/ioutil"
)

//Request
type MainRequest struct {
	Request []RequestArray `json:"requests"`
}

type RequestArray struct {
	Image ImageRequest `json:"image"`
	Feature []FeatureArray `json:"features"`
}

type ImageRequest struct {
	Content string `json:"content"`
}

type FeatureArray struct {
	Type string `json:"type"`
	MaxResult int `json:"maxResults"`
}

//Response
type MainResponse struct {
	Response []ResponseArray `json:"responses"`
}

type ResponseArray struct {
	LabelAnnotation []LabelAnnotationArray `json:"labelAnnotations"`
}

type LabelAnnotationArray struct {
	Mid string `json:"mid"`
	Description string `json:"description"`
	Score float64 `json:"score"`
	Topicality float64 `json:"topicality"`
}

func main() {

	GOOGLE_API_KEY := "<GOOGLE API KEY>"
	GOOGLE_CLOUD_VISION_URL := "https://vision.googleapis.com/v1/images:annotate"

	if len(os.Args) == 2 {
		img, err := os.Open(os.Args[1])

		if err != nil {
			fmt.Println(err)
			os.Exit(1)
		}

		defer img.Close()
		info, _ := img.Stat()
		size := info.Size()
		buffer := make([]byte, size)
		reader := bufio.NewReader(img)
		reader.Read(buffer)
		imgb64 := base64.StdEncoding.EncodeToString(buffer)	

		jsonRequest := MainRequest{
			Request: []RequestArray{
				{
					Image: ImageRequest {
						Content: imgb64,
					},
					Feature: []FeatureArray {
						{
							Type: "LABEL_DETECTION",
							MaxResult: 5,
						},
					},
				},
			},
		}

		request, _ := json.Marshal(&jsonRequest)

		response, err := http.Post(GOOGLE_CLOUD_VISION_URL + "?key=" + GOOGLE_API_KEY, "application/json", bytes.NewBuffer(request))

		if err != nil {
			fmt.Println(err)
			os.Exit(1)
		}

		defer response.Body.Close()

		jsonResponse, _ := ioutil.ReadAll(response.Body)
		var data MainResponse

		json.Unmarshal(jsonResponse, &data)

		//fmt.Printf("The image is detected as: " + data.Response[0].LabelAnnotation[0].Description)
		fmt.Println("========================================")
		for _, annotation := range data.Response[0].LabelAnnotation {
			fmt.Println("The image is detected as: " + annotation.Description)
		}
		fmt.Println("========================================")
	}
}