Computer Vision API (v2.0)

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:

  • Australia East - australiaeast.api.cognitive.microsoft.com
  • Brazil South - brazilsouth.api.cognitive.microsoft.com
  • Canada Central - canadacentral.api.cognitive.microsoft.com
  • Central India - centralindia.api.cognitive.microsoft.com
  • Central US - centralus.api.cognitive.microsoft.com
  • East Asia - eastasia.api.cognitive.microsoft.com
  • East US - eastus.api.cognitive.microsoft.com
  • East US 2 - eastus2.api.cognitive.microsoft.com
  • France Central - francecentral.api.cognitive.microsoft.com
  • Japan East - japaneast.api.cognitive.microsoft.com
  • Japan West - japanwest.api.cognitive.microsoft.com
  • Korea Central - koreacentral.api.cognitive.microsoft.com
  • North Central US - northcentralus.api.cognitive.microsoft.com
  • North Europe - northeurope.api.cognitive.microsoft.com
  • South Africa North - southafricanorth.api.cognitive.microsoft.com
  • South Central US - southcentralus.api.cognitive.microsoft.com
  • Southeast Asia - southeastasia.api.cognitive.microsoft.com
  • UK South - uksouth.api.cognitive.microsoft.com
  • West Central US - westcentralus.api.cognitive.microsoft.com
  • West Europe - westeurope.api.cognitive.microsoft.com
  • West US - westus.api.cognitive.microsoft.com
  • West US 2 - westus2.api.cognitive.microsoft.com

Recognize Text

Use this interface to get the result of a Recognize Text operation. When you use the Recognize Text interface, the response contains a field called "Operation-Location". The "Operation-Location" field contains the URL that you must use for your Get Recognize Text Operation Result operation.

For the result of a Recognize Text operation to be available, it requires an amount of time that depends on the length of the text. So, you may need to wait before using this Get Recognize Text Operation Result interface. The time you need to wait may be up to a number of seconds.

Note: this technology is currently in preview and is only available for English text.

Select the testing console in the region where you created your resource:

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 Canada Central Central India UK South Japan East Central US France Central Korea Central Japan West North Central US South Africa North UAE North Norway East West US 3 Jio India West

Request URL

Request parameters

string

If this parameter is set to "Printed", printed text recognition is performed. If "Handwritten" is specified, handwriting recognition is performed. (Note: This parameter is case sensitive.) This is a required parameter and cannot be empty.​

Request headers

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 and BMP.
  • Image file size must be less than 4MB.
  • Image dimensions must be at least 50 x 50, at most 4200 x 4200.

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

Response 202

The service has accepted the request and will start processing later.
It will return Accepted immediately and include an "Operation-Location" header. Client side should further query the operation status using the URL specified in this header. The operation ID will expire in 48 hours.

Operation-Location Client side should use this URL to query operation status/result.
Example: https://[region].api.cognitiveservices.microsoft.com/vision/v2.0/textOperations/49a36324-fc4b-4387-aa06-090cfbf0064f.

Response 415

Unsupported media type error. "Content-Type" does not match the post content.

  • For image URL, "Content-Type" should be application/json
  • For binary image data, "Content-Type" should be application/octet-stream

{
    "error": {
        "code": "BadArgument",
        "message": "Unsupported media type."
    }
}

Response 400

Error code and message returned in JSON:

Error Code Description
BadArgument Bad or unrecognizable request JSON or binary file.
InvalidImageURL Image URL is badly formatted.
FailedToDownloadImage Failed to download image from input URL.
InvalidImage The input data is not a valid image.
UnsupportedImageFormat Image format unsupported. Supported formats include JPEG, PNG and BMP.
InvalidImageSize The input image is too large. It should not be larger than 4MB.
InvalidImageDimension The input image dimension is out of range. The maximum image size is 4200 x 4200 pixels, and the minimum image size is 50 x 50 pixels. 

{ 
    "error": {
        "code": "BadArgument", 
        "message": "Invalid input."
    }
}

Response 500

Returns 500 if there's any internal error.

{
    "error": {
        "code": "Unspecified", 
        "message": "Internal server error."
    }
}

Response 503

Returns 503 if transient faults occurred when dealing with Microsoft Azure storage services.

{
    "error": {
        "code": "StorageException", 
        "message": "Transient faults occurred when dealing with Microsoft Azure storage services, please try it later."
    }
}

Code samples

@ECHO OFF

curl -v -X POST "https://westus.api.cognitive.microsoft.com/vision/v2.0/recognizeText?mode={string}"
-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["mode"] = "{string}";
            var uri = "https://westus.api.cognitive.microsoft.com/vision/v2.0/recognizeText?" + 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://westus.api.cognitive.microsoft.com/vision/v2.0/recognizeText");

            builder.setParameter("mode", "{string}");

            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
            "mode": "{string}",
        };
      
        $.ajax({
            url: "https://westus.api.cognitive.microsoft.com/vision/v2.0/recognizeText?" + $.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://westus.api.cognitive.microsoft.com/vision/v2.0/recognizeText";
    NSArray* array = @[
                         // Request parameters
                         @"entities=true",
                         @"mode={string}",
                      ];
    
    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://westus.api.cognitive.microsoft.com/vision/v2.0/recognizeText');
$url = $request->getUrl();

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

$request->setHeader($headers);

$parameters = array(
    // Request parameters
    'mode' => '{string}',
);

$url->setQueryVariables($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
    'mode': '{string}',
})

try:
    conn = httplib.HTTPSConnection('westus.api.cognitive.microsoft.com')
    conn.request("POST", "/vision/v2.0/recognizeText?%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
    'mode': '{string}',
})

try:
    conn = http.client.HTTPSConnection('westus.api.cognitive.microsoft.com')
    conn.request("POST", "/vision/v2.0/recognizeText?%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://westus.api.cognitive.microsoft.com/vision/v2.0/recognizeText')
uri.query = URI.encode_www_form({
    # Request parameters
    'mode' => '{string}'
})

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