Solution 1:

OdeToCode posted great service for this stuff. So with this simple directive you can easily preview and even see the progress bar:

.directive("ngFileSelect",function(){    
  return {
    link: function($scope,el){          
      el.bind("change", function(e){          
        $scope.file = (e.srcElement || e.target).files[0];
        $scope.getFile();
      });          
    }        
  }

It is working in all modern browsers!

Example: http://plnkr.co/edit/y5n16v?p=preview

Solution 2:

JavaScript

 $scope.setFile = function(element) {
  $scope.currentFile = element.files[0];
   var reader = new FileReader();

  reader.onload = function(event) {
    $scope.image_source = event.target.result
    $scope.$apply()

  }
  // when the file is read it triggers the onload event above.
  reader.readAsDataURL(element.files[0]);
}

Html

<img ng-src="{{image_source}}">
<input type="file" id="trigger" class="ng-hide" onchange="angular.element(this).scope().setFile(this)" accept="image/*">

This worked for me.

Solution 3:

See the Image Upload Widget from the Jasney extension of Bootstrap v3

Solution 4:

  // start Picture Preview    
    $scope.imageUpload = function (event) {
        var files = event.target.files;

        for (var i = 0; i < files.length; i++) {
            var file = files[i];
            var reader = new FileReader();
            reader.onload = $scope.imageIsLoaded;
            reader.readAsDataURL(file);
        }
    }

    $scope.imageIsLoaded = function (e) {
        $scope.$apply(function () {
            $scope.img = e.target.result;            
        });
    }


<input type='file' ng-model-instant onchange="angular.element(this).scope().imageUpload(event)" />
<img class="thumb" ng-src="{{img}}" />