Computer Vision API - v1.0

The Computer Vision API provides state-of-the-art algorithms to process images and return information. For example, it can be used to determine if an image contains mature content, or it can be used to find all the faces in an image. It also has other features like estimating dominant and accent colors, categorizing the content of images, and describing an image with complete English sentences. Additionally, it can also intelligently generate images thumbnails for displaying large images effectively.

This API is currently available in:

  • West US - westus.api.cognitive.microsoft.com
  • West US 2 - westus2.api.cognitive.microsoft.com
  • East US - eastus.api.cognitive.microsoft.com
  • East US 2 - eastus2.api.cognitive.microsoft.com
  • West Central US - westcentralus.api.cognitive.microsoft.com
  • South Central US - southcentralus.api.cognitive.microsoft.com
  • West Europe - westeurope.api.cognitive.microsoft.com
  • North Europe - northeurope.api.cognitive.microsoft.com
  • Southeast Asia - southeastasia.api.cognitive.microsoft.com
  • East Asia - eastasia.api.cognitive.microsoft.com
  • Australia East - australiaeast.api.cognitive.microsoft.com
  • Brazil South - brazilsouth.api.cognitive.microsoft.com

Get Thumbnail

This operation generates a thumbnail image with the user-specified width and height. By default, the service analyzes the image, identifies the region of interest (ROI), and generates smart cropping coordinates based on the ROI. Smart cropping helps when you specify an aspect ratio that differs from that of the input image

A successful response contains the thumbnail image binary. If the request failed, the response contains an error code and a message to help determine what went wrong.

Upon failure, the error code and an error message are returned. The error code could be one of InvalidImageUrl, InvalidImageFormat, InvalidImageSize, InvalidThumbnailSize, NotSupportedImage, FailedToProcess, Timeout, or InternalServerError.

Http Method

POST

West US West US 2 East US East US 2 West Central US South Central US West Europe North Europe Southeast Asia East Asia Australia East Brazil South

Request URL

Request parameters

number

Width of the thumbnail. It must be between 1 and 1024. Recommended minimum of 50.

number

Height of the thumbnail. It must be between 1 and 1024. Recommended minimum of 50.

(optional)
boolean

Boolean flag for enabling smart cropping.

Request headers

(optional)
string
Media type of the body sent to the API.
string
Subscription key which provides access to this API. Found in your Cognitive Services accounts.

Request body

Input passed within the POST body. Supported input methods: raw image binary or image URL.

Input requirements:

  • Supported image formats: JPEG, PNG, GIF, BMP.
  • Image file size must be less than 4MB.
  • Image dimensions should be greater than 50 x 50.

{"url":"http://example.com/images/test.jpg"}
[Binary image data]
[Binary image data]

Response 200

Return thumbnail image.

Response 400

Possible Errors:

  • InvalidImageUrl
    Image URL is badly formatted or not accessible.
  • InvalidImageFormat
    Input data is not a valid image.
  • InvalidImageSize
    Input image is too large.
  • InvalidThumbnailSize
    Specified thumbnail size is not in allowed range.

{
    "code":"InvalidImageFormat",
	"requestId":"B8D802CF-DD8F-4E61-B15C-9E6C5844CCBC",
	"message":"The input file is not in a valid image format that the service can support. "
}

Response 415

Unsupported media type error. Content-Type is not in the allowed types:

  • For an image URL: Content-Type should be application/json
  • For a binary image data: Content-Type should be application/octet-stream or multipart/form-data

{
    "code":"BadArgument",
    "message":"Invalid Media Type"
}

Response 500

Possible Errors:

  • FailedToProcess
    Failed to process the image.
  • Timeout
    Image processing time out.
  • InternalServerError
    Internal server error.

{
    "code":"FailedToProcess",
	"requestId":"B8D802CF-DD8F-4E61-B15C-9E6C5844CCBC",
	"message":"Could not extract image features"
}

Code samples

@ECHO OFF

curl -v -X POST "https://westcentralus.api.cognitive.microsoft.com/vision/v1.0/generateThumbnail?width={number}&height={number}&smartCropping=true"
-H "Content-Type: application/json"
-H "Ocp-Apim-Subscription-Key: {subscription key}"

--data-ascii "{body}" 
using System;
using System.Net.Http.Headers;
using System.Text;
using System.Net.Http;
using System.Web;

namespace CSHttpClientSample
{
    static class Program
    {
        static void Main()
        {
            MakeRequest();
            Console.WriteLine("Hit ENTER to exit...");
            Console.ReadLine();
        }
        
        static async void MakeRequest()
        {
            var client = new HttpClient();
            var queryString = HttpUtility.ParseQueryString(string.Empty);

            // Request headers
            client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", "{subscription key}");

            // Request parameters
            queryString["width"] = "{number}";
            queryString["height"] = "{number}";
            queryString["smartCropping"] = "true";
            var uri = "https://westcentralus.api.cognitive.microsoft.com/vision/v1.0/generateThumbnail?" + queryString;

            HttpResponseMessage response;

            // Request body
            byte[] byteData = Encoding.UTF8.GetBytes("{body}");

            using (var content = new ByteArrayContent(byteData))
            {
               content.Headers.ContentType = new MediaTypeHeaderValue("< your content type, i.e. application/json >");
               response = await client.PostAsync(uri, content);
            }

        }
    }
}	
// // This sample uses the Apache HTTP client from HTTP Components (http://hc.apache.org/httpcomponents-client-ga/)
import java.net.URI;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class JavaSample 
{
    public static void main(String[] args) 
    {
        HttpClient httpclient = HttpClients.createDefault();

        try
        {
            URIBuilder builder = new URIBuilder("https://westcentralus.api.cognitive.microsoft.com/vision/v1.0/generateThumbnail");

            builder.setParameter("width", "{number}");
            builder.setParameter("height", "{number}");
            builder.setParameter("smartCropping", "true");

            URI uri = builder.build();
            HttpPost request = new HttpPost(uri);
            request.setHeader("Content-Type", "application/json");
            request.setHeader("Ocp-Apim-Subscription-Key", "{subscription key}");


            // Request body
            StringEntity reqEntity = new StringEntity("{body}");
            request.setEntity(reqEntity);

            HttpResponse response = httpclient.execute(request);
            HttpEntity entity = response.getEntity();

            if (entity != null) 
            {
                System.out.println(EntityUtils.toString(entity));
            }
        }
        catch (Exception e)
        {
            System.out.println(e.getMessage());
        }
    }
}

<!DOCTYPE html>
<html>
<head>
    <title>JSSample</title>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
</head>
<body>

<script type="text/javascript">
    $(function() {
        var params = {
            // Request parameters
            "width": "{number}",
            "height": "{number}",
            "smartCropping": "true",
        };
      
        $.ajax({
            url: "https://westcentralus.api.cognitive.microsoft.com/vision/v1.0/generateThumbnail?" + $.param(params),
            beforeSend: function(xhrObj){
                // Request headers
                xhrObj.setRequestHeader("Content-Type","application/json");
                xhrObj.setRequestHeader("Ocp-Apim-Subscription-Key","{subscription key}");
            },
            type: "POST",
            // Request body
            data: "{body}",
        })
        .done(function(data) {
            alert("success");
        })
        .fail(function() {
            alert("error");
        });
    });
</script>
</body>
</html>
#import <Foundation/Foundation.h>

int main(int argc, const char * argv[])
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    
    NSString* path = @"https://westcentralus.api.cognitive.microsoft.com/vision/v1.0/generateThumbnail";
    NSArray* array = @[
                         // Request parameters
                         @"entities=true",
                         @"width={number}",
                         @"height={number}",
                         @"smartCropping=true",
                      ];
    
    NSString* string = [array componentsJoinedByString:@"&"];
    path = [path stringByAppendingFormat:@"?%@", string];

    NSLog(@"%@", path);

    NSMutableURLRequest* _request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:path]];
    [_request setHTTPMethod:@"POST"];
    // Request headers
    [_request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    [_request setValue:@"{subscription key}" forHTTPHeaderField:@"Ocp-Apim-Subscription-Key"];
    // Request body
    [_request setHTTPBody:[@"{body}" dataUsingEncoding:NSUTF8StringEncoding]];
    
    NSURLResponse *response = nil;
    NSError *error = nil;
    NSData* _connectionData = [NSURLConnection sendSynchronousRequest:_request returningResponse:&response error:&error];

    if (nil != error)
    {
        NSLog(@"Error: %@", error);
    }
    else
    {
        NSError* error = nil;
        NSMutableDictionary* json = nil;
        NSString* dataString = [[NSString alloc] initWithData:_connectionData encoding:NSUTF8StringEncoding];
        NSLog(@"%@", dataString);
        
        if (nil != _connectionData)
        {
            json = [NSJSONSerialization JSONObjectWithData:_connectionData options:NSJSONReadingMutableContainers error:&error];
        }
        
        if (error || !json)
        {
            NSLog(@"Could not parse loaded json with error:%@", error);
        }
        
        NSLog(@"%@", json);
        _connectionData = nil;
    }
    
    [pool drain];

    return 0;
}
<?php
// This sample uses the Apache HTTP client from HTTP Components (http://hc.apache.org/httpcomponents-client-ga/)
require_once 'HTTP/Request2.php';

$request = new Http_Request2('https://westcentralus.api.cognitive.microsoft.com/vision/v1.0/generateThumbnail');
$url = $request->getUrl();

$headers = array(
    // Request headers
    'Content-Type' => 'application/json',
    'Ocp-Apim-Subscription-Key' => '{subscription key}',
);

$request->setHeader($headers);

$parameters = array(
    // Request parameters
    'width' => '{number}',
    'height' => '{number}',
    'smartCropping' => 'true',
);

$url->setQueryVariables($parameters);

$request->setMethod(HTTP_Request2::METHOD_POST);

// Request body
$request->setBody("{body}");

try
{
    $response = $request->send();
    echo $response->getBody();
}
catch (HttpException $ex)
{
    echo $ex;
}

?>
########### Python 2.7 #############
import httplib, urllib, base64

headers = {
    # Request headers
    'Content-Type': 'application/json',
    'Ocp-Apim-Subscription-Key': '{subscription key}',
}

params = urllib.urlencode({
    # Request parameters
    'width': '{number}',
    'height': '{number}',
    'smartCropping': 'true',
})

try:
    conn = httplib.HTTPSConnection('westcentralus.api.cognitive.microsoft.com')
    conn.request("POST", "/vision/v1.0/generateThumbnail?%s" % params, "{body}", headers)
    response = conn.getresponse()
    data = response.read()
    print(data)
    conn.close()
except Exception as e:
    print("[Errno {0}] {1}".format(e.errno, e.strerror))

####################################

########### Python 3.2 #############
import http.client, urllib.request, urllib.parse, urllib.error, base64

headers = {
    # Request headers
    'Content-Type': 'application/json',
    'Ocp-Apim-Subscription-Key': '{subscription key}',
}

params = urllib.parse.urlencode({
    # Request parameters
    'width': '{number}',
    'height': '{number}',
    'smartCropping': 'true',
})

try:
    conn = http.client.HTTPSConnection('westcentralus.api.cognitive.microsoft.com')
    conn.request("POST", "/vision/v1.0/generateThumbnail?%s" % params, "{body}", headers)
    response = conn.getresponse()
    data = response.read()
    print(data)
    conn.close()
except Exception as e:
    print("[Errno {0}] {1}".format(e.errno, e.strerror))

####################################
require 'net/http'

uri = URI('https://westcentralus.api.cognitive.microsoft.com/vision/v1.0/generateThumbnail')
uri.query = URI.encode_www_form({
    # Request parameters
    'width' => '{number}',
    'height' => '{number}',
    'smartCropping' => 'true'
})

request = Net::HTTP::Post.new(uri.request_uri)
# Request headers
request['Content-Type'] = 'application/json'
# Request headers
request['Ocp-Apim-Subscription-Key'] = '{subscription key}'
# Request body
request.body = "{body}"

response = Net::HTTP.start(uri.host, uri.port, :use_ssl => uri.scheme == 'https') do |http|
    http.request(request)
end

puts response.body