private async void OpenImageFolder()
        {
            var source = _uiService.OpenFolderDialog();

            if (string.IsNullOrEmpty(source))
            {
                return;
            }

            var prevImageList = new List <PrevImage>();
            await Task.Factory.StartNew(() => {
                var filters = new[] { "jpg", "jpeg", "png", "gif", "tiff", "bmp" };
                var files   = FileUtils.GetFilesFrom(source, filters, true);
                foreach (var image in files.Select(x => new Models.PrevImage(x)))
                {
                    prevImageList.Add(image);
                }
            });

            if (!prevImageList.Any())
            {
                _uiService.ShowError(Constants.MissingImage);
                return;
            }
            else
            {
                ImageList.Clear();
                foreach (var image in prevImageList)
                {
                    ImageList.Add(image);
                }
                RefreshCommands();
            }
        }