ngImgCrop doesn't work properly with ng-flow

[luizadavtyan]

I am using ng-flow package to upload images. After user uploads image, i open bootstrap modal in which user does the cropping.
Here is sample of my code.
the image upload part:

<div class="profice-pic-wrap">
	<div class="thumbnail round" ng-hide="$flow.files.length">
	    <img flow-btn src="img/placeholder-person.jpg" style="cursor: pointer;" class="round thum" />
	</div>
	<div class="thumbnail" ng-show="$flow.files.length">
	   <img class="thum round" flow-btn flow-img="$flow.files[0]" ng-src="{{outputImageNew}}" style="cursor:pointer;"/>
	</div>
</div>

the cropping modal:

<div id="cropModal" class="modal fade" role="dialog">
	<div class="modal-dialog">
	   <div class="modal-content">
		      <div class="modal-header">
		      </div>
		      <div class="modal-body">
		        <div class="cropArea">
			        <img-crop image="imageString" result-image="$root.outputImage" area-type="square"></img-crop>
			</div>
		     </div>
		      <div class="modal-footer">
		        <button type="button" class="btn btn-default" translate="ok" translate-default="&nbsp;" ng-click="hideModal()"></button>
		     </div>
	   </div>
	</div>
</div>

code from my controller:

$scope.processFiles = function(files){
	$('#cropModal').modal({
	 backdrop: 'static',
		 keyboard: false
	})
	$('#cropModal').modal('show');
	$('#cropModal').on('shown.bs.modal', function() {
	$scope.imageStrings = [];
	$rootScope.outputImage = null;
	$scope.imageString = null;
	$scope.inputImage = null;
	var fileReader = new FileReader();
	fileReader.onload = function (event) {
	$scope.$apply(function($scope){
	    	      var uri = event.target.result;
		              $scope.imageString = uri;
	    	        });
	    	      };		          
	 fileReader.readAsDataURL(files[0].file);
	    })
	};

$scope.hideModal = function() {
	$('#cropModal').modal('hide');
	$scope.outputImageNew = $rootScope.outputImage;
}

When i upload an image, modal opens and i do the cropping. After that i close the modal and the cropped image appears in the img with ng-src="{{outputImageNew}}". But if i do this process several times, when modal opens i can see the previous uploaded image in my modal for a moment(or images, changing very quickly, if i repeat the process several times). Sometimes the image doesn't even appear in modal, it only shows the last uploaded one.