A Simple Post Request to Google Cloud Vision API in R #rstats #google

gcv_http.R

#-- BASED ON https://cloud.google.com/vision/docs/request#json_request_format --#

# image url on Google Cloud Storage
imgURI <- "gs://vacation_room/dublin-001.jpg"

# Requests are POST requests to 
endpoint <- "https://vision.googleapis.com/v1/images:annotate"

#### remember to set api token in ``options``
# options(gcv_api_token = "YOUR_API_TOKEN")

## authenticate using API token method
if(!is.null(getOption("gcv_api_token"))){
    baseURI <- paste0(endpoint, "?key=", getOption("gcv_api_token"))
}

# request body
body <- sprintf('{
        "requests":[
            {
                "image":{
                    "source":{
                        "imageUri":
                            "%s"
                    }
                },
                "features":[
                    {
                        "type":"LABEL_DETECTION",
                        "maxResults":%i
                    }
                    ]
            }
            ]
        }', imgURI, 5)

# send post request
res <- httr::POST(baseURI, body = body, encode = "json")

## extract content (specific mime type)
lbs <- httr::content(res, type = "application/json")

# convert into data frame
lbs$responses[[1]]$labelAnnotations %>% bind_rows()

## The End

@ashleylijie Fixed typo