Cette API est-elle le moyen le plus rapide et le plus simple d'ajouter une analyse d'image rentable à vos applications?

Thushara Wedagedara

il y a 4 ans

To add cost-effective image analysis to your applications, this article will walk you through Azure API, how to obtain a subscription key to access Azure API, and how to make requests to Azure REST API using an IDE software with REST Client Feature.

Qu'est-ce qu'une API Azure?

Azure is a cloud computing platform offered by Microsoft with more than 200 available services. Azure provides various client libraries and a REST API to access those services. There’s a free tier to get you up and running which allows you to access several services free many of which remain free as long as you don’t exceed some quite generous monthly limits. We are going to use the “Cognitive Search” service to perform Image analysis. The Cognitive Search service is an always-free tier so you should never need to pay for it.

Comment obtenir une clé d'abonnement pour accéder à l'API Azure?

To access the Azure REST API, we need a subscription key. A subscription key is a key assigned to a ‘resource’. So we need to create a resource first. To create a resource, you need an active Azure Subscription. Please visit this link to create a subscription:

https://azure.microsoft.com/free/cognitive-services/

Une fois que vous avez configuré l'abonnement Azure, vous devez créer une ressource de vision par ordinateur. Assurez-vous d'avoir sélectionné la bonne région géographique car vous ne pourrez pas la modifier ultérieurement. Visitez ce lien pour créer la ressource:

https://portal.azure.com/#create/Microsoft.CognitiveServicesComputerVision

To get the Subscription key of your resource, open the resource and go to “Keys and Endpoints”. There you can see two keys and the location which needs to make our REST API call.

Comment faire une demande à l'API Azure REST à l'aide du client Delphi REST?

L'appel de l'API REST à partir du client Delphi est facile. Il vous suffit de définir quelques paramètres et vous pouvez l'exécuter même au moment de la conception. Laissez faire une application DEMO. Faites d'abord glisser et déposez ces composants dans un forum.

TRESTClient

TRESTRequest

TRESTResponse

Placez également des contrôles d'entrée pour obtenir l'URL de l'API, la clé d'abonnement et l'URL de l'image. Placer un TButton to start the request. The content type of the REST Client must be “application / json“. Now set the client and response properties of the TRESTRequest component to the client and response components we placed earlier. Also set the method to “rmPOST“.

Le code du bouton Démarrer ressemble à ceci:

procedure TfrmMain.btnStartClick(Sender: TObject);
 var
   lparam : Trestrequestparameter;
   imgProcessed: bool;
   jsonObj, jsonStatus: TJSONObject;
 begin
   memResponse.Lines.Clear;
   RESTClient.BaseURL := edAPIURL.Text;
   RESTRequest.Method:=rmpost;
   imgProcessed := false;
   try
     RESTRequest.Params.Clear;
     RESTResponse.RootElement := '';
     lparam := RESTRequest.Params.AddItem;
     lparam.name := 'Ocp-Apim-Subscription-Key';
     lparam.Value := edSubKey.Text;
     lparam.ContentType := ctNone;
     lparam.Kind := pkHTTPHEADER;
     //This one is Important otherwise the '==' will get url encoded
     lparam.Options := [poDoNotEncode];
lparam := RESTRequest.Params.AddItem; 
lparam.name := 'data'; 
lparam.Value := '{"url":"' + edImgURL.Text + '"}'; 
lparam.ContentType := ctAPPLICATION_JSON; 
lparam.Kind := pkGETorPOST; 
RESTRequest.Execute; 
if not RESTResponse.Status.Success then   showmessage(RESTResponse.StatusText + ' ' +  inttostr(RESTResponse.StatusCode)) 
else 
begin   
memResponse.Lines.Add(RESTResponse.JSONText); 
end;
finally
end;
end;

procedure TfrmMain.btnStartClick(Sender: TObject);

var

lparam : Trestrequestparameter;

imgProcessed: bool;

jsonObj, jsonStatus: TJSONObject;

commencer

memResponse.Lines.Clair;

RESTClient.BaseURL := edAPIURL.Text;

RESTRequest.Method:=rmpost;

imgProcessed := false;

try

RESTRequest.Params.Clair;

RESTResponse.RootElement := '';

lparam := RESTRequest.Params.AddItem;

lparam.name := 'Ocp-Apim-Subscription-Key';

lparam.Value := edSubKey.Text;

lparam.ContentType := ctNone;

lparam.Kind := pkHTTPHEADER;

//This one is Important otherwise the '==' will get url encoded

lparam.Options := [poDoNotEncode];

lparam := RESTRequest.Params.AddItem;

lparam.name := 'data';

lparam.Value := '{"url":"' + edImgURL.Text + '"}';

lparam.ContentType := ctAPPLICATION_JSON;

lparam.Kind := pkGETorPOST;

RESTRequest.Execute;

if ne pas RESTResponse.Status.Success then showmessage(RESTResponse.StatusText + ' ' + inttostr(RESTResponse.StatusCode))

autre

commencer

memResponse.Lines.Add(RESTResponse.JSONText);

end;

finally

end;

This code will add new parameter to the TRESTRequest and set the subscription key. The subscription key must pass as an HTTP header and the name should be “Clé d'abonnement Ocp-Apim“. The value parameter is the subscription key we copied earlier. Also it’s important to include the option “poDoNotEncode“, otherwise it will encode the key. Also the base URL of the TRESTClient doit être défini. Lorsque nous entrons l'URL de base du client Azure, nous devons tenir compte de la région de notre ressource. Il doit s'agir du sous-domaine de l'URL. L'URL de base ressemblera à ceci.

<a href="https://eastus.api.cognitive.microsoft.com/vision/v3.2/analyze?visualFeatures=Description" target="_blank" rel="noreferrer noopener nofollow">https://eastus.api.cognitive.microsoft.com/vision/v3.2/analyze?visualFeatures=Description</a>

1	<une href="https://eastus.api.cognitive.microsoft.com/vision/v3.2/analyze?visualFeatures=Description" target="_blank" rel="noreferrer noopener nofollow">https://eastus.api.cognitive.microsoft.com/vision/v3.2/analyze?visualFeatures=Description</a>

Replace “Eastus” with your region or it will ne pas travail. Il existe également de nombreux paramètres que vous pouvez passer par cette URL. Veuillez visiter ce lien pour trouver tous les paramètres.

https://docs.microsoft.com/en-us/azure/cognitive-services/computer-vision/vision-api-how-to-topics/howtocallvisionapi

In this demo we passed “visualFeatures = Description” which will describe our image in one sentence. Also we have to pass our image URL in JSON format. To do that, add new parameter to the TRESTRequest and set the content type to “ctAPPLICATION_JSON” , set name to “URL” and the value in this format:

{"url":"IMAGE_URL"}

1	{"url":"IMAGE_URL"}

Notre application finale devrait ressembler à ceci.

Vous pouvez télécharger l'application DEMO depuis GitHub: https://github.com/checkdigits/ImageAnalysisClient_example

Well, try it for yourself and see – is it the fastest way to add image analysis to your Windows, macOS and mobile applications?