<button type="submit" ng-click="clickUpload()">
<span>Upload Image</span>
</button>
<input id="uploader" hidden type="file" ng-accept="'.jpg,.png,.gif,.jpeg,.webp'" ngf-select="uploadFile(selectedFile)" ng-model="selectedFile" name="file" />

$scope.uploadFile = function (selectedFile) {
    alert(selectedFile);
}