Detect NSFW Content in an Image in Swift

Maintaining a website that allows users to upload content is a demanding task; with the wide variety of content that is available online, it’s hard to keep track of which materials contain racy or inappropriate content, and which do not. If you frequently encounter content on your site that could damage your company’s reputation, it may be time to integrate a safety net. In this quick tutorial, we will show you how to automatically detect ‘Not Safe for Work’ content from an image by using an API in Swift.

Simply input your image file and API key into the below example code to call the function:

import Foundation
#if canImport(FoundationNetworking)
import FoundationNetworking
#endif
var semaphore = DispatchSemaphore (value: 0)
let parameters = [
     [
          "key": "imageFile",
          "src": "/path/to/file",
          "type": "file"
     ]] as [[String : Any]]
let boundary = "Boundary-\(UUID().uuidString)"
var body = ""
var error: Error? = nil
for param in parameters {
     if param["disabled"] == nil {
          let paramName = param["key"]!
          body += "--\(boundary)\r\n"
          body += "Content-Disposition:form-data; name=\"\(paramName)\""
          if param["contentType"] != nil {
               body += "\r\nContent-Type: \(param["contentType"] as! String)"
          }
          let paramType = param["type"] as! String
          if paramType == "text" {
               let paramValue = param["value"] as! String
               body += "\r\n\r\n\(paramValue)\r\n"
          } else {
               let paramSrc = param["src"] as! String
               let fileData = try NSData(contentsOfFile:paramSrc, options:[]) as Data
               let fileContent = String(data: fileData, encoding: .utf8)!
               body += "; filename=\"\(paramSrc)\"\r\n"
                 + "Content-Type: \"content-type header\"\r\n\r\n\(fileContent)\r\n"
          }
     }
}
body += "--\(boundary)--\r\n";
let postData = body.data(using: .utf8)
var request = URLRequest(url: URL(string: "https://api.cloudmersive.com/image/nsfw/classify")!,timeoutInterval: Double.infinity)
request.addValue("multipart/form-data", forHTTPHeaderField: "Content-Type")
request.addValue("YOUR-API-KEY-HERE", forHTTPHeaderField: "Apikey")
request.addValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
request.httpMethod = "POST"
request.httpBody = postData
let task = URLSession.shared.dataTask(with: request) { data, response, error in 
     guard let data = data else {
          print(String(describing: error))
          semaphore.signal()
          return
     }
     print(String(data: data, encoding: .utf8)!)
     semaphore.signal()
}
task.resume()
semaphore.wait()

If you need to obtain an API key, you can do so by registering for a free account on the Cloudmersive website; this will provide 800 calls/month across any of our APIs.