认知服务计算机视觉 API 返回“缓存控制错误”

Question

我正在尝试在 JavaScript 中使用 Microsoft 认知服务计算机视觉 API。我必须将 canvas 图像上传到 API 并获得结果。我使用相同的程序 'param' 和 'URL' 改变 Face API 并且它工作得很好。但是在 Computer Vision API 中它给出了这个错误： "Cache-Control: no-cache\r\nPragma: no-cache\r\nContent-Type: application/json; charset=utf-8\r\nExpires: -1\r\n"

我的代码是：

var apiKey = "<KEY>";
var apiUrl = "https://westus.api.cognitive.microsoft.com/face/v1.0/detect";
var params = {
            // Request parameters
            "maxCandidates": "1",
        };
        
$('#btn').click(function () {
  var file = document.getElementById('filename').files[0];
  CallAPI(file, apiUrl, apiKey);
    


 });
 
navigator.getUserMedia = ( navigator.getUserMedia ||
                         navigator.webkitGetUserMedia ||
                            navigator.mozGetUserMedia ||
                            navigator.msGetUserMedia);

var video;
var webcamStream;
function startWebcam() {
    if (navigator.getUserMedia) {
  navigator.getUserMedia (
            {
                video: true,
                audio: false
            },

         function(localMediaStream) {
                 video = document.querySelector('video');
                 video.src = window.URL.createObjectURL(localMediaStream);
                  webcamStream = localMediaStream;
               },

            function(err) {
                  console.log("The following error occured: " + err);
               }
        );
    } 
    else {
     console.log("getUserMedia not supported");
    }  
}

function stopWebcam() {
          webcamStream.stop();
       }

makeblob = function (dataURL) {
    var BASE64_MARKER = ';base64,';
    if (dataURL.indexOf(BASE64_MARKER) == -1) {
        var parts = dataURL.split(',');
        var contentType = parts[0].split(':')[1];
        var raw = decodeURIComponent(parts[1]);
        return new Blob([raw], { type: contentType });
    }
    var parts = dataURL.split(BASE64_MARKER);
    var contentType = parts[0].split(':')[1];
    var raw = window.atob(parts[1]);
    var rawLength = raw.length;

    var uInt8Array = new Uint8Array(rawLength);

    for (var i = 0; i < rawLength; ++i) {
        uInt8Array[i] = raw.charCodeAt(i);
    }

    return new Blob([uInt8Array], { type: contentType });
}


function snapshot() {
 canvas = document.getElementById("myCanvas");
 ctx = canvas.getContext('2d');
 ctx.drawImage(video, 0,0, canvas.width, canvas.height);
 var dataurl= canvas.toDataURL();
 CallAPI(dataurl, apiUrl, apiKey);
}
setInterval(snapshot,10000);


function CallAPI(file, apiUrl, apiKey)
{ console.log("api called");
  $.ajax({
            url: "https://westus.api.cognitive.microsoft.com/vision/v1.0/analyze?" + $.param(params),
            beforeSend: function(xhrObj){
                // Request headers
                xhrObj.setRequestHeader("Content-Type","application/json");
                xhrObj.setRequestHeader("Ocp-Apim-Subscription-Key",apiKey);
            },
   type: "POST",
   data: makeblob(file),
   processData: false
  })

 .done(function (response) {
   ProcessResult(response);
   console.log("done");
 })

 .fail(function (error) {
   $("#response").text(error.getAllResponseHeaders());
            var str= JSON.stringify(error.getAllResponseHeaders())
   console.log(str);
 });
}
 
function ProcessResult(response)
{
 // var data = JSON.parse(response);
    var string= JSON.stringify(response);
    var string = string.substring(1, string.length-1);
    var data= JSON.parse(string);
    console.log(string)   

}

请帮助并提出更好的方法。

Answer 1

在您的 $.ajax 调用中，Content-Type 需要设置为 application/octet-stream。

另外提醒一下，Vision 和 Face API 有不同的 API 键。

$.ajax({
    url: apiUrl + "?" + $.param(params),
    beforeSend: function(xhrObj){
        // Request headers
        xhrObj.setRequestHeader("Content-Type","application/octet-stream");
        xhrObj.setRequestHeader("Ocp-Apim-Subscription-Key", apiKey);
    },
    type: "POST",
    data: makeblob(file),
    processData: false
})

认知服务计算机视觉 API 返回“缓存控制错误”

Cognitive Service Computer vision API returning ' cache control error'

javascript

api

computer-vision

microsoft-cognitive