Serving images with Akka-http

Question

I'm trying to serve an image using akka-http, but keep getting error in the browser about MIME type:

Resource interpreted as Document but transferred with MIME type image/png: "http://localhost/banners/ci.png".

That's the server-side code:

pathPrefix("banners"){
        get {
          entity(as[HttpRequest]) { requestData =>
            complete {
              val fullPath = requestData.uri.path.toString match {
                case _ => Paths.get(workingDirectory +  requestData.uri.path.toString)
              }

              val contentType = getExtensions(fullPath.toString) match {
                case "jpg" => ContentType(MediaTypes.`image/jpeg`)
                case "png" => ContentType(MediaTypes.`image/png`)
                case "html" => ContentTypes.`text/html(UTF-8)`
              }

              val h = RawHeader("Access-Control-Allow-Origin","*")
              val byteArray = Files.readAllBytes(fullPath)
              HttpResponse(OK, entity = HttpEntity(contentType,byteArray)).withHeaders(h)

            }
          }
        }
      } ~

Here is the response headers copied from chrome developer console:

HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Server: akka-http/10.0.7
Date: Fri, 26 May 2017 13:08:04 GMT
Content-Type: image/png
Content-Length: 581

Any ideas how can I fix it ?