Javascript – Upload properly encoded (base64?) image to SharePoint with AngularJS

I am able to upload an image file to SharePoint, but it is not being recognized as an image. I have tried utilizing the following directive based on research that states images need to be base64 encoded when uploaded into SharePoint, but it still uploads a file that appears to be corrupt: https://github.com/adonespitogo/angular-base64-upload

I am happy to use this directive, but am unsure of how to pass what I need into SharePoint's REST API.

The original iteration I had does not use this directive, but is more of a straight upload attempt.

What I need to achieve is as follows:

1) Successfully upload an image without it being "corrupted", and does this require base64 encoding/how do I achieve this?

2) Upload images by their name (not "test.jpg") and have some metadata (ex. upload an image with the title or department name it belongs to)

Iteration 1: No Directive
Here is my HTML (Please note that the controller is tied to the page via ng-route):

 <div class="col-md-12">
        <form>
            <input type="file" onchange="angular.element(this).scope().filesChanged(this)" data-ng-model="files" multiple>
            <button data-ng-click="upload()">Submit</button>
            <li data-ng-repeat="file in files">{{file.name}}</li>
        </form>            
    </div>

Here is my controller:

$scope.filesChanged = function (elm) {
        $scope.files = elm.files
        $scope.$apply();
    }
    $scope.upload = function () {
        var fd = new FormData()
        angular.forEach($scope.files,function(file){
            fd.append('file',file)
        })
            $http.post("/sites/asite/_api/web/lists/getByTitle('Images')/RootFolder/Files/add(url='test.jpg',overwrite='true')", fd,
                    {
                        transformRequest: angular.identity,
                        headers: {
                            'Content-Type':undefined, 'X-RequestDigest': $("#__REQUESTDIGEST").val()}
                }).success(function (d) {
                    console.log(d);
                });
            }

UPDATE: I believe the issue is isolated to my $http post to SharePoint. Using the directive mentioned above, I am able to output the base64, but am unsure how to pass this into my post for upload.

Iteration 2: Using Directive
Here is my current HTML using the https://github.com/adonespitogo/angular-base64-upload directive:

<form>
<input type="file" data-ng-model="files" base-sixty-four-input>
<button data-ng-click="upload()">Submit</button>
</form>

My controller that is posting the corrupted image files to SharePoint:

$scope.upload = function () {
        console.log($scope.files); // Output result from upload directive
        $http({
            method: 'POST',
            url: "/sites/ens/_api/web/lists/getByTitle('Report Images')/RootFolder/Files/add(url='" + $scope.files.filename +"',overwrite='true')", 
            headers: {
                'Content-Type': false ,
                'X-RequestDigest': $("#__REQUESTDIGEST").val()
            },
            data: $scope.files,
         }).success(function (data) {
            console.log(data);
        });
    }

Update 2: Using SP.RequestExecutor as follows creates the same result. A file upload but not rendering. This happens for images and documents:

Iteration 3: Using Directive and SP.RequestExecutor

$scope.upload = function () {
    var dataURL = 'data:' + $scope.files.filetype + ';' + 'base64,' + $scope.files.base64;
    var createitem = new SP.RequestExecutor("/sites/asite");
    createitem.executeAsync({
        url: "/sites/asite/_api/web/lists/getByTitle('Images')/RootFolder/Files/add(url='" + $scope.files.filename + "')",
        method: "POST",
        binaryStringRequestBody: true,
        body: dataURL,
        success: fsucc,
        error: ferr,
        state: "Update"
    });

    function fsucc(data) {
        alert('success');
    }
    function ferr(data) {
        alert('error\n\n' + data.statusText + "\n\n" + data.responseText);
    }
}

Update 3: Using .ajax as follows, it will successfully post the image, but when using $http, it corrupts the image.

Iteration 3: Using .Ajax (works)

function uploadFileSync(spWebUrl , library, filename, file) 
    {
        var reader = new FileReader();
        reader.onloadend = function(evt) 
        {
            if (evt.target.readyState == FileReader.DONE) 
            {
                var buffer = evt.target.result;
                var completeUrl = spWebUrl
                  + "/_api/web/lists/getByTitle('"+ library +"')"
                  + "/RootFolder/Files/add(url='"+ filename +"',overwrite='true')?"
                  + "@TargetLibrary='"+library+"'&@TargetFileName='"+ filename +"'";

                $.ajax({
                    url: completeUrl,
                    type: "POST",
                    data: buffer,
                    async: false,
                    processData: false,
                    headers: {
                        "accept": "application/json;odata=verbose",
                        "X-RequestDigest": $("#__REQUESTDIGEST").val(),
                        "content-length": buffer.byteLength
                    },
                    complete: function (data) {
                        //uploaded pic url
                        console.log(data.responseJSON.d.ServerRelativeUrl);
                        $route.reload();
                    },
                    error: function (err) {
                        alert('failed');
                    }
                });

            }
        };
        reader.readAsArrayBuffer(file);
    }  

Iteration 4: Using $http (corrupts image)

function uploadFileSync(spWebUrl , library, filename, file) 
{
    var reader = new FileReader();
    reader.onloadend = function (evt) {
        if (evt.target.readyState == FileReader.DONE) {
            var buffer = evt.target.result;
            var completeUrl = spWebUrl
              + "/_api/web/lists/getByTitle('" + library + "')"
              + "/RootFolder/Files/add(url='" + filename + "',overwrite='true')?"
              + "@TargetLibrary='" + library + "'&@TargetFileName='" + filename + "'";

            $http({
                url: completeUrl,
                method: "POST",
                data: buffer,
                processData: false,
                headers: {
                    "accept": "application/json;odata=verbose",
                    "X-RequestDigest": $("#__REQUESTDIGEST").val(),
                    "content-length": buffer.byteLength
                }
            }).success(function (data) {
                //uploaded pic url
                //console.log(data.responseJSON.d.ServerRelativeUrl);
                $route.reload();
            }).error(function (err) {
                alert(err);
            });
        }
    };
    reader.readAsArrayBuffer(file);
}