By Longhow Lam
Introduction
In my previous blog post I used the Microsoft Translator API in my BonAppetit Shiny app to recommend restaurants to tourists. I’m getting a little bit addicted to the Microsoft API’s, they can be fun to use . In this blog post I will briefly describe some of the Project Oxford API’s of Microsoft.
The API’s can be called from within R, and if you combine them with other API’s, for example Twitter, then interesting “Twitter face” analyses can be done. See my “TweetFace” shiny app to analyse faces that can be found on Twitter.
Project Oxford
The API’s of Project Oxford can be categorized into:
- Computer Vision,
- Face,
- Video,
- Speech and
- Language.
The free tier subscription provides 5000 API calls per month (with a rate limit of 20 calls per minute). I focused my experiments on the computer vision and face API’s, a lot of functionality is available to analyze images. For example, categorization of images, adult content detection, OCR, face recognition, gender analysis, age estimation and emotion detection.
Calling the API’s from R
The httr package provides very convenient functions to call the Microsoft API’s. You need to sign-up first and obtain a key. Let’s do a simple test on Angelina Jolie by using the face detect API.
Angelina Jolie, picture link
library(httr)
faceURL = "https://api.projectoxford.ai/face/v1.0/detect?returnFaceId=true&returnFaceLandmarks=true&returnFaceAttributes=age,gender,smile,facialHair"
img.url = 'http://www.buro247.com/images/Angelina-Jolie-2.jpg'
faceKEY = '123456789101112131415'
mybody = list(url = img.url)
faceResponse = POST(
url = faceURL,
content_type('application/json'), add_headers(.headers = c('Ocp-Apim-Subscription-Key' = faceKEY)),
body = mybody,
encode = 'json'
)
faceResponse
Response [https://api.projectoxford.ai/face/v1.0/detect?returnFaceId=true&returnFaceLandmarks=true&returnFaceAttributes=age,gender,smile,facialHair]
Date: 2015-12-16 10:13
Status: 200
Content-Type: application/json; charset=utf-8
Size: 1.27 kB
If the call was successful a “Status: 200” is returned and the response object is filled with interesting information. The API returns the information as JSON which is parsed by R into nested lists.
AngelinaFace = content(faceResponse)[[1]] names(AngelinaFace) [1] "faceId" "faceRectangle" "faceLandmarks" "faceAttributes" AngelinaFace$faceAttributes $gender [1] "female" $age [1] 32.6 $facialHair $facialHair$moustache [1] 0 $facialHair$beard [1] 0 $facialHair$sideburns [1] 0
Well, the API recognized the gender …read more
Source:: r-bloggers.com
