图像裁剪已将图像转换为base64格式

Question

我正在使用ngImgCrop进行图像裁剪，但生成的图像是base64编码的，而我要发布的端点仅支持multipart-form-data。我很困惑如何将其转换为普通图像。

Angular Plugin：ngImgCrop

我的HTML代码：

        <div>Select an image file: <input type="file" id="fileInput" /></div>
        <div class="cropArea" style="background: #E4E4E4; overflow: hidden; width:500px; height:350px;">
            <img-crop image="myImage" result-image="myCroppedImage"></img-crop>
        </div>
        <div>Cropped Image:</div>
        <img ng-src="{{myCroppedImage}}"/>
        <button ng-click="convertImage(myCroppedImage)">Upload Image</button>

在角度控制器中：

$scope.convertImage = function(imgBase64){
                    var image = new Image();
                    var Base64 = {_keyStr:"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",encode:function(e){var t="";var n,r,i,s,o,u,a;var f=0;e=Base64._utf8_encode(e);while(f<e.length){n=e.charCodeAt(f++);r=e.charCodeAt(f++);i=e.charCodeAt(f++);s=n>>2;o=(n&3)<<4|r>>4;u=(r&15)<<2|i>>6;a=i&63;if(isNaN(r)){u=a=64}else if(isNaN(i)){a=64}t=t+this._keyStr.charAt(s)+this._keyStr.charAt(o)+this._keyStr.charAt(u)+this._keyStr.charAt(a)}return t},decode:function(e){var t="";var n,r,i;var s,o,u,a;var f=0;e=e.replace(/[^A-Za-z0-9\+\/\=]/g,"");while(f<e.length){s=this._keyStr.indexOf(e.charAt(f++));o=this._keyStr.indexOf(e.charAt(f++));u=this._keyStr.indexOf(e.charAt(f++));a=this._keyStr.indexOf(e.charAt(f++));n=s<<2|o>>4;r=(o&15)<<4|u>>2;i=(u&3)<<6|a;t=t+String.fromCharCode(n);if(u!=64){t=t+String.fromCharCode(r)}if(a!=64){t=t+String.fromCharCode(i)}}t=Base64._utf8_decode(t);return t},_utf8_encode:function(e){e=e.replace(/\r\n/g,"\n");var t="";for(var n=0;n<e.length;n++){var r=e.charCodeAt(n);if(r<128){t+=String.fromCharCode(r)}else if(r>127&&r<2048){t+=String.fromCharCode(r>>6|192);t+=String.fromCharCode(r&63|128)}else{t+=String.fromCharCode(r>>12|224);t+=String.fromCharCode(r>>6&63|128);t+=String.fromCharCode(r&63|128)}}return t},_utf8_decode:function(e){var t="";var n=0;var r=c1=c2=0;while(n<e.length){r=e.charCodeAt(n);if(r<128){t+=String.fromCharCode(r);n++}else if(r>191&&r<224){c2=e.charCodeAt(n+1);t+=String.fromCharCode((r&31)<<6|c2&63);n+=2}else{c2=e.charCodeAt(n+1);c3=e.charCodeAt(n+2);t+=String.fromCharCode((r&15)<<12|(c2&63)<<6|c3&63);n+=3}}return t}};
                    image = Base64.decode(imgBase64);
                    console.log(image);
                    image.src = imgBase64;
                    image.name="random";
                    console.log(image);
                    $scope.upload(image);
                };

                var handleFileSelect = function(evt) {
                    var file = evt.currentTarget.files[0];
                    var reader = new FileReader();
                    reader.onload = function (evt) {
                        $scope.$apply(function($scope){
                            console.log(evt.target.result);
                            $scope.myImage = evt.target.result;
                        });
                    };
                    reader.readAsDataURL(file);
                    console.log(reader);
                };
                angular.element(document.querySelector('#fileInput')).on('change',handleFileSelect);