Use cURL for Microsoft Vision API

Question

Hi I'm trying to use Microsoft Vision API to get a description of an image which is posted from LINE messenger apps.

Now I code by PHP and use curl, I dont't get error message but it seems something wrong. I only get the message; "I can see!".

I get logs below.

2016-12-30T10:25:14.550661+00:00 app[web.1]: [30-Dec-2016 19:25:14 Asia/Tokyo] stdClass Object
2016-12-30T10:25:14.550706+00:00 app[web.1]: (
2016-12-30T10:25:14.550758+00:00 app[web.1]:     [code] => InvalidImageUrl
2016-12-30T10:25:14.550801+00:00 app[web.1]:     [requestId] => 871afc35-7c01-478b-9c0c-c51d365bfba4
2016-12-30T10:25:14.550853+00:00 app[web.1]:     [message] => Can't fetch the image.
2016-12-30T10:25:14.550855+00:00 app[web.1]: )
2016-12-30T10:25:14.550855+00:00 app[web.1]: 
2016-12-30T10:25:15.299165+00:00 heroku[router]: at=info method=POST path="/callback.php" host=kasabot30.herokuapp.com request_id=2fc2bb0d-4ca5-4d0c-94c4-540345bb3726 fwd="203.104.146.152" dyno=web.1 connect=1ms service=1715ms status=200 bytes=150
2016-12-30T10:25:15.291527+00:00 app[web.1]: 10.154.74.169 - - [30/Dec/2016:10:25:13 +0000] "POST /callback.php HTTP/1.1" 200 - "-" "LineBotWebhook/1.0
2016-12-30T10:29:47.964240+00:00 app[web.1]: 10.109.176.159 - - [30/Dec/2016:10:29:47 +0000] "GET /Lenna.png HTTP/1.1" 200 473831 "-" "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36
2016-12-30T10:29:47.967859+00:00 heroku[router]: at=info method=GET path="/Lenna.png" host=kasabot30.herokuapp.com request_id=f3fe060b-3740-4660-8044-e8bd4b07f6eb fwd="219.208.70.99" dyno=web.1 connect=0ms service=13ms status=200 bytes=474068

Could you please help me to find my mistake? Except for Vision API, other codes are working well.

Thanks so much in advance.

https://dev.projectoxford.ai/docs/services/56f91f2d778daf23d8ec6739/operations/56f91f2e778daf14a499e1fa/console

//Function to post on Microsoft Vision API
$url = 'https://api.projectoxford.ai/vision/v1.0/analyze?visualFeatures=Description&language=en';
$api_key ='MY_KEY';
$image_url = 'https://kasabot30.herokuapp.com/Lenna.png';

$post_data = array(
   "url:" => "$image_url"
);

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POSTFIELDS,
json_encode($post_data)
);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
   'Content-Type: application/json',
   'Ocp-Apim-Subscription-Key:'.$api_key
));
$image_json_string = curl_exec($ch);
curl_close($ch);

$image_json = json_decode($image_json_string);
$image_description = $image_json->{"description"}->{"captions"}[0]->{"text"};

$response_format_text = [
array(
  "type" => "text",
  "text" => "I can see".$image_description."!"
)
];

//Function to post on LINE Message API
$ch = curl_init("https://api.line.me/v2/bot/message/reply");
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($post_data));
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    'Content-Type: application/json;charser=UTF-8',
        'Authorization: Bearer ' . $accessToken
));
$result = curl_exec($ch);
curl_close($ch);

Answer 1

Based on the additional information gained in the discussion in the comments it turned out that the post data sent to the API was structured incorrectly. The key to hand over an image URL should be url, not url::

$post_data = array(
   'url' => $image_url
);

With that change the API delivered the expected result.