Using HttpURLConnection increases the size of the uploaded image

Question

Today I'm trying to upload and image to a server. I found that a lot of developers recommend the use of HttpURLConnection. The performance is very important for me, so I tried to optimize the code the most I know how to do it. The problem I faced is that the uploaded images are considerably larger than the original ones.

If anyone sees something that can be done better, it would be of great help

This is my class to upload a bitmap:

private class SubirImagen extends AsyncTask<Bitmap, Integer, APIResponse<String>> {


    String token;
    String boundary = "***" + System.currentTimeMillis() + "***";
    String crlf = "\r\n";
    String twoHyphens = "--";


    public SubirImagen(String token) {
        this.token = token;
    }

    @Override
    protected void onPostExecute(APIResponse<String> stringAPIResponse) {
        progressBar.setVisibility(View.INVISIBLE);
        if (stringAPIResponse.getErrors().isEmpty()) {
            new File(pathToFile.getPath()).delete();
            imagenCambiada = false;
            pathToFile = null;
            controler.showToast(getContext(), stringAPIResponse.getData());
        } else {
            controler.showToast(getContext(), stringAPIResponse.getErrors().get(0).getErrorMsg());
        }
        super.onPostExecute(stringAPIResponse);
    }

    @Override
    protected void onPreExecute() {
        progressBar.setVisibility(View.VISIBLE);
        progressBar.setProgress(0);
        super.onPreExecute();
    }

    @Override
    protected void onProgressUpdate(Integer... values) {
        progressBar.setProgress(values[0]);
    }


    @Override
    protected APIResponse<String> doInBackground(Bitmap... bitmaps) {
        ByteArrayOutputStream bao1 = new ByteArrayOutputStream();
        bitmaps[0].compress(Bitmap.CompressFormat.JPEG, 100, bao1);
        byte[] ba1 = bao1.toByteArray();
        int size = (twoHyphens.length() * 3) + (boundary.length() * 2) + (crlf.length() * 5) +
                ("Content-Disposition: form-data; name=\"imagen\";filename=\"imagen\"".length()) +
                ba1.length;
        HttpURLConnection urlConnection = null;
        try {
            URL url = new URL("http://192.168.137.1:8080/BochoGameAPI/usuario/uploadFotoPerfil");
            urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestProperty("Authorization", token);
            urlConnection.setUseCaches(false);
            urlConnection.setDoInput(true);
            urlConnection.setDoOutput(true);
            urlConnection.setRequestMethod("POST");
            urlConnection.setRequestProperty("Connection", "Keep-Alive");
            urlConnection.setRequestProperty("Cache-Control", "no-cache");
            urlConnection.setRequestProperty("ENCTYPE", "multipart/form-data");
            urlConnection.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
            urlConnection.setFixedLengthStreamingMode(size);
            DataOutputStream request = new DataOutputStream(urlConnection.getOutputStream());
            request.writeBytes(twoHyphens + boundary + crlf);
            request.writeBytes("Content-Disposition: form-data; name=\"imagen\";filename=\"imagen\"" + crlf);
            request.writeBytes(crlf);
            request.flush();
            int progress = 0;
            int bytesRead;
            byte buf[] = new byte[1024];
            BufferedInputStream bufInput = new BufferedInputStream(new ByteArrayInputStream(ba1));
            while ((bytesRead = bufInput.read(buf)) != -1) {
                // write output
                request.write(buf, 0, bytesRead);
                request.flush();
                progress += bytesRead;
                // update progress bar
                publishProgress((progress * 100) / size);
            }
            request.write(ba1);
            request.writeBytes(crlf);
            request.writeBytes(twoHyphens + boundary + twoHyphens + crlf);
            request.flush();
            request.close();

            int code = urlConnection.getResponseCode();
            if (code != 200) {
                throw new IOException("Invalid response from server: " + code);
            }

            BufferedReader rd = new BufferedReader(new InputStreamReader(
                    urlConnection.getInputStream()));


            String line;
            Gson gson = new Gson();
            Type typeToken = new TypeToken<APIResponse<String>>() {
            }.getType();
            APIResponse<String> apiResponse = null;
            while ((line = rd.readLine()) != null) {
                apiResponse = gson.fromJson(line, typeToken);
            }
            rd.close();
            return apiResponse;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (urlConnection != null) {
                urlConnection.disconnect();
            }
        }
        return null;
    }
}

Original image, 1.57 mb:

Uploaded image, 4.19 mb: