nick.jw.park nick.jw.park - 2 months ago 30x
Android Question

Watson Visual Recognition error "Invalid image data. Supported formats are JPG, PNG, and GIF" when uploading image from Android Studio

I have been wrecking my brain over this for a while and would really appreciate if someone who have some insight into this problem could help me out!

I am trying to upload an image to Watson's Visual Recognition API using POST from Android Studio (by taking a picture using a camera).

I have managed to
- save image after taking a picture with a camera
- show it as a bitmap image on the app

and I am trying to upload the file to the Watson API, but I keep getting this error

"description": "Invalid image data. Supported formats are JPG, PNG,
and GIF."

I would really appreciate if anyone could provide some insight to what I am doing wrong here. Thanks in advance!

I am using HttpUrlConnection and DataOutputStream to POST right now and the code is as follows:

imgName and imgPath are all correctly identified, and name="images_file" is how Watson Visual Recognition API requests name to be

public void uploadImage(){
HttpURLConnection conn = null;
DataOutputStream dos = null;
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1 * 1024 * 1024;

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();


URL url = new URL("");
conn= (HttpURLConnection) url.openConnection();
FileInputStream fileInputStream = new FileInputStream(file);
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("ENCTYPE", "multipart/form-data");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
conn.setRequestProperty("images_file", imgPath);

dos = new DataOutputStream(conn.getOutputStream());

dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\"images_file\"; filename = \"" + imgName + "\"" + lineEnd);

bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];

bytesRead =, 0, bufferSize);
while (bytesRead > 0) {

dos.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead =, 0, bufferSize);


// send multipart form data necesssary after file data...
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

// Responses from the server (code and message)
serverResponseCode = conn.getResponseCode();
String serverResponseMessage = conn.getResponseMessage();

Log.i("uploadFile", "HTTP Response is : "
+ serverResponseMessage + ": " + serverResponseCode);

if(serverResponseCode == 200){

BufferedReader br = new BufferedReader(new InputStreamReader((conn.getInputStream())));
StringBuilder sb = new StringBuilder();
String output;
while ((output = br.readLine()) !=null) {
Log.d("debugging", sb.toString());

runOnUiThread(new Runnable() {
public void run() {

String msg = "File Upload Completed.\n\n See uploaded file here : \n\n"

Toast.makeText(getApplicationContext(), "File Upload Complete.",


//close the streams //

} catch (MalformedURLException ex) {


runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(getApplicationContext(), "MalformedURLException",

Log.e("Upload file to server", "error: " + ex.getMessage(), ex);
} catch (Exception e) {


runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(getApplicationContext(), "Got Exception : see logcat ",
Log.e("Debugging", "Exception : "
+ e.getMessage(), e);
Log.d("Debugging", "responseCode:" + serverResponseCode);


Visual Recognition has an SDK(client library) in Java. You just need to add the dependency to your build.gradle.

  compile ''


VisualRecognition service = new VisualRecognition(VisualRecognition.VERSION_DATE_2016_05_20);

ClassifyImagesOptions options = new ClassifyImagesOptions.Builder()
  .images(new File("car.png"))

VisualClassification result = service.classify(options)
  .enqueue(new ServiceCallback<List<Dialog>>() {
      public void onResponse(List<Dialog> response) {

      public void onFailure(Exception e) {
      // on failure

This example has a CameraHelper class with utility methods to get the file path or InputStream of a picture in Android.