Edit in JSFiddle

var myapp = angular.module('sampleapp', ["highcharts-ng"]);

myapp.controller('samplecontoller', function ($scope) {

    $scope.highchartsNG = {
        options: {
            chart: {
                type: 'bar'
            }
        },
        series: [{
            data: [10, 15, 12, 8, 7]
        }],
        title: {
            text: 'bar chart'
        },
        loading: false
    }
 $scope.saveAsBinary = function( ){

 var svg = document.getElementById('highchartContainer')
                                       .children[0].innerHTML;
 var base_image = new Image();
    
 svg = "data:image/svg+xml,"+svg;
    
 base_image.src = svg;
    
 $('#binaryImage').attr('src', svg);

}

});

<div ng-app="sampleapp">
    <div ng-controller="samplecontoller">
        
        <button ng-click="saveAsBinary()">Save as Binary</button>
        <highchart id="highchartContainer" config="highchartsNG"></highchart>
        <img id="binaryImage"/>
    </div>
</div>