This encodes a bitmap in base64

encodeImageInBase64.java

private String encodeImage(Bitmap bitmap) {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
    byte[] byteArray = baos.toByteArray();
    return Base64.encodeToString(byteArray, Base64.DEFAULT);
}