diff --git a/Azaion.Annotator/App.xaml.cs b/Azaion.Annotator/App.xaml.cs
index 0127f66..78103e1 100644
--- a/Azaion.Annotator/App.xaml.cs
+++ b/Azaion.Annotator/App.xaml.cs
@@ -1,4 +1,5 @@
-using System.Reflection;
+using System.Data;
+using System.Reflection;
 using System.Windows;
 using System.Windows.Input;
 using System.Windows.Threading;
@@ -35,6 +36,8 @@ public partial class App : Application
             {
                 services.AddSingleton<MainWindow>();
                 services.AddSingleton<HelpWindow>();
+                services.AddSingleton<DatasetExplorer>();
+                services.AddSingleton<IGalleryManager, GalleryManager>();
                 services.AddMediatR(c => c.RegisterServicesFromAssembly(Assembly.GetExecutingAssembly()));
                 services.AddSingleton<LibVLC>(_ => new LibVLC());
                 services.AddSingleton<FormState>();
diff --git a/Azaion.Annotator/DTO/Config.cs b/Azaion.Annotator/DTO/Config.cs
index b66f0d5..4836f63 100644
--- a/Azaion.Annotator/DTO/Config.cs
+++ b/Azaion.Annotator/DTO/Config.cs
@@ -10,10 +10,13 @@ namespace Azaion.Annotator.DTO;
 
 public class Config
 {
+    public const string ThumbnailPrefix = "_thumb";
+
     public string VideosDirectory { get; set; }
     public string LabelsDirectory { get; set; }
     public string ImagesDirectory { get; set; }
     public string ResultsDirectory { get; set; }
+    public string ThumbnailsDirectory { get; set; }
 
     public List<AnnotationClass> AnnotationClasses { get; set; } = [];
 
@@ -31,6 +34,14 @@ public class Config
 
     public List<string> VideoFormats { get; set; }
     public List<string> ImageFormats { get; set; }
+
+    public ThumbnailConfig ThumbnailConfig { get; set; }
+}
+
+public class ThumbnailConfig
+{
+    public Size Size { get; set; }
+    public int Border { get; set; }
 }
 
 public interface IConfigRepository
@@ -48,9 +59,11 @@ public class FileConfigRepository(ILogger<FileConfigRepository> logger) : IConfi
     private const string DEFAULT_LABELS_DIR = "labels";
     private const string DEFAULT_IMAGES_DIR = "images";
     private const string DEFAULT_RESULTS_DIR = "results";
+    private const string DEFAULT_THUMBNAILS_DIR = "thumbnails";
 
     private static readonly Size DefaultWindowSize = new(1280, 720);
     private static readonly Point DefaultWindowLocation = new(100, 100);
+    private static readonly Size DefaultThumbnailSize = new(240, 135);
 
     private static readonly List<string> DefaultVideoFormats = ["mp4", "mov", "avi"];
     private static readonly List<string> DefaultImageFormats = ["jpg", "jpeg", "png", "bmp"];
@@ -68,13 +81,19 @@ public class FileConfigRepository(ILogger<FileConfigRepository> logger) : IConfi
                 LabelsDirectory = Path.Combine(exePath, DEFAULT_LABELS_DIR),
                 ImagesDirectory = Path.Combine(exePath, DEFAULT_IMAGES_DIR),
                 ResultsDirectory = Path.Combine(exePath, DEFAULT_RESULTS_DIR),
+                ThumbnailsDirectory = Path.Combine(exePath, DEFAULT_THUMBNAILS_DIR),
 
                 WindowLocation = DefaultWindowLocation,
                 WindowSize = DefaultWindowSize,
                 ShowHelpOnStart = true,
 
                 VideoFormats = DefaultVideoFormats,
-                ImageFormats = DefaultImageFormats
+                ImageFormats = DefaultImageFormats,
+                ThumbnailConfig = new ThumbnailConfig
+                {
+                    Size = DefaultThumbnailSize,
+                    Border = 10
+                }
             };
         }
         var str = File.ReadAllText(CONFIG_PATH);
diff --git a/Azaion.Annotator/DTO/FormState.cs b/Azaion.Annotator/DTO/FormState.cs
index 8374f2c..c92d0e5 100644
--- a/Azaion.Annotator/DTO/FormState.cs
+++ b/Azaion.Annotator/DTO/FormState.cs
@@ -9,11 +9,14 @@ public class FormState
     public SelectionState SelectionState { get; set; } = SelectionState.None;
 
     public MediaFileInfo? CurrentMedia { get; set; }
-    public Size CurrentVideoSize { get; set; }
     public string VideoName => string.IsNullOrEmpty(CurrentMedia?.Name)
         ? ""
         : Path.GetFileNameWithoutExtension(CurrentMedia.Name).Replace(" ", "");
+
+    public string CurrentMrl { get; set; }
+    public Size CurrentVideoSize { get; set; }
     public TimeSpan CurrentVideoLength { get; set; }
+
     public int CurrentVolume { get; set; } = 100;
     public ObservableCollection<AnnotationResult> AnnotationResults { get; set; } = [];
 
diff --git a/Azaion.Annotator/DTO/Label.cs b/Azaion.Annotator/DTO/Label.cs
index 4cb019c..a78d054 100644
--- a/Azaion.Annotator/DTO/Label.cs
+++ b/Azaion.Annotator/DTO/Label.cs
@@ -1,4 +1,5 @@
 using System.Globalization;
+using System.IO;
 using System.Windows;
 using Newtonsoft.Json;
 
@@ -146,7 +147,17 @@ public class YoloLabel : Label
             return null;
         }
     }
-    
+
+    public static async Task<List<YoloLabel>> ReadFromFile(string filename, CancellationToken cancellationToken)
+    {
+        var str = await File.ReadAllTextAsync(filename, cancellationToken);
+
+        return str.Split(Environment.NewLine)
+            .Select(Parse)
+            .Where(ann => ann != null)
+            .ToList()!;
+    }
+
     public override string ToString() => $"{ClassNumber} {CenterX:F5} {CenterY:F5} {Width:F5} {Height:F5}".Replace(',', '.');
     
 }
\ No newline at end of file
diff --git a/Azaion.Annotator/DatasetExplorer.xaml b/Azaion.Annotator/DatasetExplorer.xaml
new file mode 100644
index 0000000..341fc0e
--- /dev/null
+++ b/Azaion.Annotator/DatasetExplorer.xaml
@@ -0,0 +1,26 @@
+<Window x:Class="Azaion.Annotator.DatasetExplorer"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:local="clr-namespace:Azaion.Annotator"
+        mc:Ignorable="d"
+        Title="Браузер анотацій" Height="450" Width="800">
+    <Grid
+        Name="MainGrid"
+        ShowGridLines="False"
+        Background="Black"
+        HorizontalAlignment="Stretch">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="*"></RowDefinition>
+            <RowDefinition Height="32"></RowDefinition>
+        </Grid.RowDefinitions>
+        <Grid.ColumnDefinitions>
+            <ColumnDefinition Width="150" />
+            <ColumnDefinition Width="4"/>
+            <ColumnDefinition Width="*" />
+            <ColumnDefinition Width="4"/>
+            <ColumnDefinition Width="200" />
+        </Grid.ColumnDefinitions>
+    </Grid>
+</Window>
diff --git a/Azaion.Annotator/DatasetExplorer.xaml.cs b/Azaion.Annotator/DatasetExplorer.xaml.cs
new file mode 100644
index 0000000..615836e
--- /dev/null
+++ b/Azaion.Annotator/DatasetExplorer.xaml.cs
@@ -0,0 +1,30 @@
+using System.Windows;
+
+namespace Azaion.Annotator;
+
+public partial class DatasetExplorer : Window
+{
+    private CancellationTokenSource _cancellationTokenSource;
+
+    public DatasetExplorer(IGalleryManager galleryManager)
+    {
+        _cancellationTokenSource = new CancellationTokenSource();
+
+        InitializeComponent();
+        Loaded += (sender, args) =>
+        {
+            _ = Task.Run(async () =>
+            {
+                while (!_cancellationTokenSource.Token.IsCancellationRequested)
+                {
+                    await galleryManager.RefreshThumbnails(_cancellationTokenSource.Token);
+                    await Task.Delay(30000, _cancellationTokenSource.Token);
+                }
+            });
+        };
+
+        Closing += (sender, args) => _cancellationTokenSource.Cancel();
+    }
+
+
+}
\ No newline at end of file
diff --git a/Azaion.Annotator/Extensions/ThrottleExtensions.cs b/Azaion.Annotator/Extensions/ThrottleExtensions.cs
index 17d3d10..c9467c5 100644
--- a/Azaion.Annotator/Extensions/ThrottleExtensions.cs
+++ b/Azaion.Annotator/Extensions/ThrottleExtensions.cs
@@ -10,7 +10,10 @@ public static class ThrottleExt
 
         _throttleOn = true;
         await func();
-        await Task.Delay(throttleTime ?? TimeSpan.FromMilliseconds(500));
-        _throttleOn = false;
+        _ = Task.Run(() =>
+        {
+            Task.Delay(throttleTime ?? TimeSpan.FromMilliseconds(500));
+            _throttleOn = false;
+        });
     }
 }
\ No newline at end of file
diff --git a/Azaion.Annotator/GalleryManager.cs b/Azaion.Annotator/GalleryManager.cs
index 775d721..2cc5847 100644
--- a/Azaion.Annotator/GalleryManager.cs
+++ b/Azaion.Annotator/GalleryManager.cs
@@ -1,10 +1,129 @@
-namespace Azaion.Annotator;
+using System.Drawing;
+using System.Drawing.Drawing2D;
+using System.Drawing.Imaging;
+using System.IO;
+using Azaion.Annotator.DTO;
+using Color = System.Drawing.Color;
+using Size = System.Windows.Size;
 
-public class GalleryManager
+namespace Azaion.Annotator;
+
+public class GalleryManager : IGalleryManager
 {
+    private readonly Config _config;
 
-    public void CreateThumbnails()
+    public int ThumbnailsCount { get; set; }
+    public int ImagesCount { get; set; }
+
+    public GalleryManager(Config config)
     {
-
+        _config = config;
     }
+
+    public async Task RefreshThumbnails(CancellationToken cancellationToken)
+    {
+        var dir = new DirectoryInfo(_config.ThumbnailsDirectory);
+        if (!dir.Exists)
+            Directory.CreateDirectory(_config.ThumbnailsDirectory);
+
+        var prefixLen = Config.ThumbnailPrefix.Length;
+        var thumbnailsDir = new DirectoryInfo(_config.ThumbnailsDirectory);
+
+        var thumbnails = thumbnailsDir.GetFiles()
+            .Select(x => Path.GetFileNameWithoutExtension(x.Name)[..^prefixLen])
+            .GroupBy(x => x)
+            .Select(gr => gr.Key)
+            .ToHashSet();
+        ThumbnailsCount = thumbnails.Count;
+
+        var files = new DirectoryInfo(_config.ImagesDirectory).GetFiles();
+        ImagesCount = files.Length;
+
+        foreach (var img in files)
+        {
+            var imgName = Path.GetFileNameWithoutExtension(img.Name);
+            if (thumbnails.Contains(imgName))
+                continue;
+
+            var bitmap = await GenerateThumbnail(img, cancellationToken);
+            var thumbnailName = Path.Combine(thumbnailsDir.FullName, $"{imgName}{Config.ThumbnailPrefix}.jpg");
+            bitmap.Save(thumbnailName, ImageFormat.Jpeg);
+
+            ThumbnailsCount++;
+        }
+    }
+
+    private async Task<Bitmap> GenerateThumbnail(FileInfo img, CancellationToken cancellationToken)
+    {
+        var width = (int)_config.ThumbnailConfig.Size.Width;
+        var height = (int)_config.ThumbnailConfig.Size.Height;
+
+        var imgName = Path.GetFileNameWithoutExtension(img.Name);
+        var labelName = Path.Combine(_config.LabelsDirectory, $"{imgName}.txt");
+
+        var originalImage = Image.FromFile(img.FullName);
+
+        var bitmap = new Bitmap(width, height);
+
+        using var g = Graphics.FromImage(bitmap);
+        g.CompositingQuality = CompositingQuality.HighSpeed;
+        g.SmoothingMode = SmoothingMode.HighSpeed;
+        g.InterpolationMode = InterpolationMode.Default;
+
+        var size = new Size(originalImage.Width, originalImage.Height);
+        var labels = (await YoloLabel.ReadFromFile(labelName, cancellationToken))
+            .Select(x => new CanvasLabel(x, size, size))
+            .ToList();
+
+        var thumbWhRatio = width / (float)height;
+        var border = _config.ThumbnailConfig.Border;
+
+        var labelsMinX = labels.Any() ? labels.Min(x => x.X);
+        var labelsMaxX = labels.Max(x => x.X + x.Width);
+
+        var labelsMinY = labels.Min(x => x.Y);
+        var labelsMaxY = labels.Max(x => x.Y + x.Height);
+
+        var labelsHeight = labelsMaxY - labelsMinY + 2 * border;
+        var labelsWidth = labelsMaxX - labelsMinX + 2 * border;
+
+        var frameHeight = 0.0;
+        var frameWidth = 0.0;
+        var frameX = 0.0;
+        var frameY = 0.0;
+        if (labelsWidth / labelsHeight > thumbWhRatio)
+        {
+            frameWidth = labelsWidth;
+            frameHeight = Math.Min(labelsWidth / thumbWhRatio, size.Height);
+            frameX = Math.Max(0, labelsMinX - border);
+            frameY = Math.Max(0, 0.5 * (labelsMinY + labelsMaxY - frameHeight) - border);
+        }
+        else
+        {
+            frameHeight = labelsHeight;
+            frameWidth = Math.Min(labelsHeight * thumbWhRatio, size.Width);
+            frameY = Math.Max(0, labelsMinY - border);
+            frameX = Math.Max(0, 0.5 * (labelsMinX + labelsMaxX - frameWidth) - border);
+        }
+
+        var scale = frameHeight / height;
+        g.DrawImage(originalImage, new Rectangle(0, 0, width, height), new RectangleF((float)frameX, (float)frameY, (float)frameWidth, (float)frameHeight), GraphicsUnit.Pixel);
+
+        foreach (var label in labels)
+        {
+            var color = _config.AnnotationClassesDict[label.ClassNumber].Color;
+            var brush = new SolidBrush(Color.FromArgb(color.A, color.R, color.G, color.B));
+
+            var rectangle = new RectangleF((float)((label.X - frameX) / scale), (float)((label.Y - frameY) / scale), (float)(label.Width / scale), (float)(label.Height / scale));
+            g.FillRectangle(brush, rectangle);
+        }
+        return bitmap;
+    }
+}
+
+public interface IGalleryManager
+{
+    int ThumbnailsCount { get; set; }
+    int ImagesCount { get; set; }
+    Task RefreshThumbnails(CancellationToken cancellationToken);
 }
\ No newline at end of file
diff --git a/Azaion.Annotator/MainWindow.xaml b/Azaion.Annotator/MainWindow.xaml
index eb58fa2..4fd13df 100644
--- a/Azaion.Annotator/MainWindow.xaml
+++ b/Azaion.Annotator/MainWindow.xaml
@@ -53,6 +53,7 @@
         Background="Black"
         HorizontalAlignment="Stretch">
         <Grid.RowDefinitions>
+            <RowDefinition Height="28"></RowDefinition>
             <RowDefinition Height="28"></RowDefinition>
             <RowDefinition Height="28"></RowDefinition>
             <RowDefinition Height="*"></RowDefinition>
@@ -75,6 +76,9 @@
                 <MenuItem x:Name="OpenFolderItem" 
                           Foreground="Black"
                           IsEnabled="True" Header="Відкрити папку..." Click="OpenFolderItemClick"/>
+                <MenuItem x:Name="OpenDataExplorerItem" 
+                          Foreground="Black"
+                          IsEnabled="True" Header="Відкрити браузер анотацій..." Click="OpenDataExplorerItemClick"/>
             </MenuItem>
             <MenuItem Header="Допомога" Foreground="#FFBDBCBC" Margin="0,3,0,0">
                 <MenuItem x:Name="OpenHelpWindow" 
@@ -104,8 +108,33 @@
                 . . .
             </Button>
         </Grid>
-        
-        <ListView Grid.Row="2"
+
+        <Grid
+            HorizontalAlignment="Stretch"
+            Grid.Column="0"
+            Grid.Row="2">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="50" />
+                <ColumnDefinition Width="*"/>
+            </Grid.ColumnDefinitions>
+            <Label
+                Grid.Column="0"
+                Grid.Row="0"
+                HorizontalAlignment="Stretch"
+                Margin="1"
+                Foreground="LightGray"
+                Content="Фільтр: "/>
+            <TextBox
+                Grid.Column="1"
+                Grid.Row="0"
+                HorizontalAlignment="Stretch"
+                Margin="1"
+                x:Name="TbFilter"
+                TextChanged="TbFilter_OnTextChanged">
+            </TextBox>
+        </Grid>
+
+        <ListView Grid.Row="3"
                   Grid.Column="0"
                   Name="LvFiles"
                   Background="Black"
@@ -133,7 +162,7 @@
         </ListView>
         <DataGrid x:Name="LvClasses"
                   Grid.Column="0"
-                  Grid.Row="3"
+                  Grid.Row="4"
                   Background="Black"
                   RowBackground="#252525"
                   Foreground="White"
@@ -181,7 +210,7 @@
             ResizeDirection="Columns"
             Grid.Column="1"
             Grid.Row="1"
-            Grid.RowSpan="3"
+            Grid.RowSpan="4"
             ResizeBehavior="PreviousAndNext"
             HorizontalAlignment="Stretch"
             VerticalAlignment="Stretch"
@@ -190,7 +219,7 @@
         <wpf:VideoView
             Grid.Row="1"
             Grid.Column="2"
-            Grid.RowSpan="3"
+            Grid.RowSpan="4"
             x:Name="VideoView">
             <controls:CanvasEditor x:Name="Editor"
                                    Background="#01000000"
@@ -202,7 +231,7 @@
             ResizeDirection="Columns"
             Grid.Column="3"
             Grid.Row="1"
-            Grid.RowSpan="3"
+            Grid.RowSpan="4"
             ResizeBehavior="PreviousAndNext"
             HorizontalAlignment="Stretch"
             VerticalAlignment="Stretch"
@@ -211,7 +240,7 @@
         <DataGrid x:Name="DgAnnotations"
                   Grid.Column="4"
                   Grid.Row="1"
-                  Grid.RowSpan="3"
+                  Grid.RowSpan="6"
                   Background="Black"
                   RowBackground="#252525"
                   Foreground="White"
@@ -265,14 +294,14 @@
         
         <controls:UpdatableProgressBar x:Name="VideoSlider" 
             Grid.Column="0"
-            Grid.Row="4"
+            Grid.Row="5"
             Grid.ColumnSpan="4"
             Background="#252525"
             Foreground="LightBlue">
 
         </controls:UpdatableProgressBar>
         <Grid
-            Grid.Row="5"
+            Grid.Row="6"
             Grid.Column="0"
             Background="Black"
             >
@@ -455,7 +484,7 @@
             </Button>
         </Grid>
         <StatusBar
-            Grid.Row="5"
+            Grid.Row="6"
             Grid.Column="2"
             Grid.ColumnSpan="2"
             Background="#252525"
diff --git a/Azaion.Annotator/MainWindow.xaml.cs b/Azaion.Annotator/MainWindow.xaml.cs
index 406aa1c..4136851 100644
--- a/Azaion.Annotator/MainWindow.xaml.cs
+++ b/Azaion.Annotator/MainWindow.xaml.cs
@@ -27,6 +27,7 @@ public partial class MainWindow
     private readonly IConfigRepository _configRepository;
     private readonly HelpWindow _helpWindow;
     private readonly ILogger<MainWindow> _logger;
+    private CancellationTokenSource _cancellationTokenSource = new CancellationTokenSource();
 
     public ObservableCollection<AnnotationClass> AnnotationClasses { get; set; } = new();
     private bool _suspendLayout;
@@ -34,6 +35,10 @@ public partial class MainWindow
     private readonly TimeSpan _thresholdBefore = TimeSpan.FromMilliseconds(100);
     private readonly TimeSpan _thresholdAfter = TimeSpan.FromMilliseconds(300);
     private readonly Config _config;
+    private readonly DatasetExplorer _datasetExplorer;
+
+    private ObservableCollection<MediaFileInfo> AllMediaFiles { get; set; } = new();
+    private ObservableCollection<MediaFileInfo> FilteredMediaFiles { get; set; } = new();
 
     public IntervalTree<TimeSpan, List<YoloLabel>> Annotations { get; set; } = new();
 
@@ -42,6 +47,7 @@ public partial class MainWindow
         FormState formState,
         IConfigRepository configRepository,
         HelpWindow helpWindow,
+        DatasetExplorer datasetExplorer,
         ILogger<MainWindow> logger)
     {
         InitializeComponent();
@@ -52,6 +58,7 @@ public partial class MainWindow
         _configRepository = configRepository;
         _config = _configRepository.Get();
         _helpWindow = helpWindow;
+        _datasetExplorer = datasetExplorer;
         _logger = logger;
 
         VideoView.Loaded += VideoView_Loaded;
@@ -115,12 +122,16 @@ public partial class MainWindow
 
         _mediaPlayer.Playing += async (sender, args) =>
         {
+            if (_formState.CurrentMrl == _mediaPlayer.Media?.Mrl)
+                return; //already loaded all the info
+
+            _formState.CurrentMrl = _mediaPlayer.Media?.Mrl ?? "";
             uint vw = 0, vh = 0;
             _mediaPlayer.Size(0, ref vw, ref vh);
             _formState.CurrentVideoSize = new Size(vw, vh);
             _formState.CurrentVideoLength = TimeSpan.FromMilliseconds(_mediaPlayer.Length);
 
-            await Dispatcher.Invoke(async () => await ReloadAnnotations());
+            await Dispatcher.Invoke(async () => await ReloadAnnotations(_cancellationTokenSource.Token));
             if (_formState.CurrentMedia?.MediaType != MediaTypes.Image)
                 return;
 
@@ -195,7 +206,7 @@ public partial class MainWindow
         }
     }
 
-    public async Task ReloadAnnotations()
+    public async Task ReloadAnnotations(CancellationToken cancellationToken)
     {
         _formState.AnnotationResults.Clear();
         Annotations.Clear();
@@ -211,12 +222,7 @@ public partial class MainWindow
             var name = Path.GetFileNameWithoutExtension(file.Name);
             var time = _formState.GetTime(name)!.Value;
 
-            var str = await File.ReadAllTextAsync(file.FullName);
-            var annotations = str.Split(Environment.NewLine).Select(YoloLabel.Parse)
-                .Where(ann => ann != null)
-                .ToList();
-
-            await AddAnnotation(time, annotations!);
+            await AddAnnotation(time, await YoloLabel.ReadFromFile(file.FullName, cancellationToken));
         }
     }
 
@@ -271,11 +277,11 @@ public partial class MainWindow
             HasAnnotations = labelNames.ContainsKey(Path.GetFileNameWithoutExtension(x.Name).Replace(" ", ""))
         });
 
-        var mediaFiles = videoFiles.Concat(imageFiles).ToList();
-        LvFiles.ItemsSource = new ObservableCollection<MediaFileInfo>(mediaFiles);
+        AllMediaFiles = new ObservableCollection<MediaFileInfo>(videoFiles.Concat(imageFiles).ToList());
+        LvFiles.ItemsSource = AllMediaFiles;
         TbFolder.Text = _config.VideosDirectory;
 
-        BlinkHelp(mediaFiles.Count == 0
+        BlinkHelp(AllMediaFiles.Count == 0
             ? HelpTexts.HelpTextsDict[HelpTextEnum.Initial] 
             : HelpTexts.HelpTextsDict[HelpTextEnum.PlayVideo]);
     }
@@ -296,9 +302,9 @@ public partial class MainWindow
     //     AnnotationClasses.Add(new AnnotationClass(AnnotationClasses.Count));
     //     LvClasses.SelectedIndex = AnnotationClasses.Count - 1;
     // }
-    private void OpenFolderItemClick(object sender, RoutedEventArgs e) => OpenFolder();
-    private void OpenFolderButtonClick(object sender, RoutedEventArgs e) => OpenFolder();
-    private void OpenFolder()
+    private async void OpenFolderItemClick(object sender, RoutedEventArgs e) => await OpenFolder();
+    private async void OpenFolderButtonClick(object sender, RoutedEventArgs e) => await OpenFolder();
+    private async Task OpenFolder()
     {
         var dlg = new CommonOpenFileDialog
         {
@@ -309,11 +315,26 @@ public partial class MainWindow
         if (dlg.ShowDialog() != CommonFileDialogResult.Ok)
             return;
 
-        if (!string.IsNullOrEmpty(dlg.FileName)) 
+        if (!string.IsNullOrEmpty(dlg.FileName))
+        {
             _config.VideosDirectory = dlg.FileName;
-        
+            await SaveUserSettings();
+        }
+
         ReloadFiles();
     }
+    private void TbFilter_OnTextChanged(object sender, TextChangedEventArgs e)
+    {
+        FilteredMediaFiles = new ObservableCollection<MediaFileInfo>(AllMediaFiles.Where(x => x.Name.ToLower().Contains(TbFilter.Text.ToLower())).ToList());
+        LvFiles.ItemsSource = FilteredMediaFiles;
+    }
+
+    private void OpenDataExplorerItemClick(object sender, RoutedEventArgs e)
+    {
+        _datasetExplorer.Show();
+        _datasetExplorer.Activate();
+    }
+
 
     private void PlayClick(object sender, RoutedEventArgs e)
     {
@@ -354,4 +375,3 @@ public partial class MainWindow
 
     private void Thumb_OnDragCompleted(object sender, DragCompletedEventArgs e) => _ = SaveUserSettings();
 }
-
diff --git a/Azaion.Annotator/PlayerControlHandler.cs b/Azaion.Annotator/PlayerControlHandler.cs
index 3a85a91..fbfc77c 100644
--- a/Azaion.Annotator/PlayerControlHandler.cs
+++ b/Azaion.Annotator/PlayerControlHandler.cs
@@ -8,17 +8,19 @@ using Microsoft.Extensions.Logging;
 
 namespace Azaion.Annotator;
 
-public class PlayerControlHandler(LibVLC libVLC,
-        MediaPlayer mediaPlayer,
-        MainWindow mainWindow,
-        FormState formState,
-        Config config,
-        ILogger<PlayerControlHandler> logger) :
+public class PlayerControlHandler :
     INotificationHandler<KeyEvent>,
     INotificationHandler<AnnClassSelectedEvent>,
     INotificationHandler<PlaybackControlEvent>,
     INotificationHandler<VolumeChangedEvent>
 {
+    private readonly LibVLC _libVLC;
+    private readonly MediaPlayer _mediaPlayer;
+    private readonly MainWindow _mainWindow;
+    private readonly FormState _formState;
+    private readonly Config _config;
+    private readonly ILogger<PlayerControlHandler> _logger;
+
     private const int STEP = 20;
     private const int LARGE_STEP = 5000;
     private const int RESULT_WIDTH = 1280;
@@ -35,6 +37,21 @@ public class PlayerControlHandler(LibVLC libVLC,
         { Key.PageDown, PlaybackControlEnum.Next },
     };
 
+    public PlayerControlHandler(LibVLC libVLC,
+        MediaPlayer mediaPlayer,
+        MainWindow mainWindow,
+        FormState formState,
+        Config config,
+        ILogger<PlayerControlHandler> logger)
+    {
+        _libVLC = libVLC;
+        _mediaPlayer = mediaPlayer;
+        _mainWindow = mainWindow;
+        _formState = formState;
+        _config = config;
+        _logger = logger;
+    }
+
     public async Task Handle(AnnClassSelectedEvent notification, CancellationToken cancellationToken)
     {
         SelectClass(notification.AnnotationClass);
@@ -44,15 +61,15 @@ public class PlayerControlHandler(LibVLC libVLC,
 
     private void SelectClass(AnnotationClass annClass)
     {
-        mainWindow.Editor.CurrentAnnClass = annClass;
-        foreach (var ann in mainWindow.Editor.CurrentAnns.Where(x => x.IsSelected))
+        _mainWindow.Editor.CurrentAnnClass = annClass;
+        foreach (var ann in _mainWindow.Editor.CurrentAnns.Where(x => x.IsSelected))
             ann.AnnotationClass = annClass;
-        mainWindow.LvClasses.SelectedIndex = annClass.Id;
+        _mainWindow.LvClasses.SelectedIndex = annClass.Id;
     }
 
     public async Task Handle(KeyEvent notification, CancellationToken cancellationToken)
     {
-        logger.LogInformation($"Catch {notification.Args.Key} by {notification.Sender.GetType().Name}");
+        _logger.LogInformation($"Catch {notification.Args.Key} by {notification.Sender.GetType().Name}");
 
         var key = notification.Args.Key;
         var keyNumber = (int?)null;
@@ -62,7 +79,7 @@ public class PlayerControlHandler(LibVLC libVLC,
         if ((int)key >= (int)Key.NumPad1 && (int)key <= (int)Key.NumPad9)
             keyNumber = key - Key.NumPad1;
         if (keyNumber.HasValue)
-            SelectClass(mainWindow.AnnotationClasses[keyNumber.Value]);
+            SelectClass(_mainWindow.AnnotationClasses[keyNumber.Value]);
 
         if (_keysControlEnumDict.TryGetValue(key, out var value))
             await ControlPlayback(value);
@@ -74,7 +91,7 @@ public class PlayerControlHandler(LibVLC libVLC,
     {
         switch (key)
         {
-            case Key.VolumeMute when mediaPlayer.Volume == 0:
+            case Key.VolumeMute when _mediaPlayer.Volume == 0:
                 await ControlPlayback(PlaybackControlEnum.TurnOnVolume);
                 break;
             case Key.VolumeMute:
@@ -82,15 +99,15 @@ public class PlayerControlHandler(LibVLC libVLC,
                 break;
             case Key.Up:
             case Key.VolumeUp:
-                var vUp = Math.Min(100, mediaPlayer.Volume + 5);
+                var vUp = Math.Min(100, _mediaPlayer.Volume + 5);
                 ChangeVolume(vUp);
-                mainWindow.Volume.Value = vUp;
+                _mainWindow.Volume.Value = vUp;
                 break;
             case Key.Down:
             case Key.VolumeDown:
-                var vDown = Math.Max(0, mediaPlayer.Volume - 5);
+                var vDown = Math.Max(0, _mediaPlayer.Volume - 5);
                 ChangeVolume(vDown);
-                mainWindow.Volume.Value = vDown;
+                _mainWindow.Volume.Value = vDown;
                 break;
         }
     }
@@ -98,7 +115,7 @@ public class PlayerControlHandler(LibVLC libVLC,
     public async Task Handle(PlaybackControlEvent notification, CancellationToken cancellationToken)
     {
         await ControlPlayback(notification.PlaybackControl);
-        mainWindow.VideoView.Focus();
+        _mainWindow.VideoView.Focus();
     }
 
     private async Task ControlPlayback(PlaybackControlEnum controlEnum)
@@ -114,42 +131,42 @@ public class PlayerControlHandler(LibVLC libVLC,
                     await Play();
                     break;
                 case PlaybackControlEnum.Pause:
-                    mediaPlayer.Pause();
-                    if (!mediaPlayer.IsPlaying)
-                        mainWindow.BlinkHelp(HelpTexts.HelpTextsDict[HelpTextEnum.AnnotationHelp]);
+                    _mediaPlayer.Pause();
+                    if (!_mediaPlayer.IsPlaying)
+                        _mainWindow.BlinkHelp(HelpTexts.HelpTextsDict[HelpTextEnum.AnnotationHelp]);
                     break;
                 case PlaybackControlEnum.Stop:
-                    mediaPlayer.Stop();
+                    _mediaPlayer.Stop();
                     break;
                 case PlaybackControlEnum.PreviousFrame:
-                    mediaPlayer.SetPause(true);
-                    mediaPlayer.Time -= step;
-                    mainWindow.VideoSlider.Value = mediaPlayer.Position * 100;
+                    _mediaPlayer.SetPause(true);
+                    _mediaPlayer.Time -= step;
+                    _mainWindow.VideoSlider.Value = _mediaPlayer.Position * 100;
                     break;
                 case PlaybackControlEnum.NextFrame:
-                    mediaPlayer.SetPause(true);
-                    mediaPlayer.Time += step;
-                    mainWindow.VideoSlider.Value = mediaPlayer.Position * 100;
+                    _mediaPlayer.SetPause(true);
+                    _mediaPlayer.Time += step;
+                    _mainWindow.VideoSlider.Value = _mediaPlayer.Position * 100;
                     break;
                 case PlaybackControlEnum.SaveAnnotations:
                     await SaveAnnotations();
                     break;
                 case PlaybackControlEnum.RemoveSelectedAnns:
-                    mainWindow.Editor.RemoveSelectedAnns();
+                    _mainWindow.Editor.RemoveSelectedAnns();
                     break;
                 case PlaybackControlEnum.RemoveAllAnns:
-                    mainWindow.Editor.RemoveAllAnns();
+                    _mainWindow.Editor.RemoveAllAnns();
                     break;
                 case PlaybackControlEnum.TurnOnVolume:
-                    mainWindow.TurnOnVolumeBtn.Visibility = Visibility.Collapsed;
-                    mainWindow.TurnOffVolumeBtn.Visibility = Visibility.Visible;
-                    mediaPlayer.Volume = formState.CurrentVolume;
+                    _mainWindow.TurnOnVolumeBtn.Visibility = Visibility.Collapsed;
+                    _mainWindow.TurnOffVolumeBtn.Visibility = Visibility.Visible;
+                    _mediaPlayer.Volume = _formState.CurrentVolume;
                     break;
                 case PlaybackControlEnum.TurnOffVolume:
-                    mainWindow.TurnOffVolumeBtn.Visibility = Visibility.Collapsed;
-                    mainWindow.TurnOnVolumeBtn.Visibility = Visibility.Visible;
-                    formState.CurrentVolume = mediaPlayer.Volume;
-                    mediaPlayer.Volume = 0;
+                    _mainWindow.TurnOffVolumeBtn.Visibility = Visibility.Collapsed;
+                    _mainWindow.TurnOnVolumeBtn.Visibility = Visibility.Visible;
+                    _formState.CurrentVolume = _mediaPlayer.Volume;
+                    _mediaPlayer.Volume = 0;
                     break;
                 case PlaybackControlEnum.Previous:
                     await NextMedia(isPrevious: true);
@@ -173,11 +190,11 @@ public class PlayerControlHandler(LibVLC libVLC,
     private async Task NextMedia(bool isPrevious = false)
     {
         var increment = isPrevious ? -1 : 1;
-        var check = isPrevious ? -1 : mainWindow.LvFiles.Items.Count;
-        if (mainWindow.LvFiles.SelectedIndex + increment == check)
+        var check = isPrevious ? -1 : _mainWindow.LvFiles.Items.Count;
+        if (_mainWindow.LvFiles.SelectedIndex + increment == check)
             return;
 
-        mainWindow.LvFiles.SelectedIndex += increment;
+        _mainWindow.LvFiles.SelectedIndex += increment;
         await Play();
     }
 
@@ -189,63 +206,63 @@ public class PlayerControlHandler(LibVLC libVLC,
 
     private void ChangeVolume(int volume)
     {
-        formState.CurrentVolume = volume;
-        mediaPlayer.Volume = volume;
+        _formState.CurrentVolume = volume;
+        _mediaPlayer.Volume = volume;
     }
 
     private async Task Play()
     {
-        if (mainWindow.LvFiles.SelectedItem == null)
+        if (_mainWindow.LvFiles.SelectedItem == null)
             return;
-        var mediaInfo = (MediaFileInfo)mainWindow.LvFiles.SelectedItem;
+        var mediaInfo = (MediaFileInfo)_mainWindow.LvFiles.SelectedItem;
 
-        formState.CurrentMedia = mediaInfo;
-        mediaPlayer.Stop();
-        mainWindow.Title = $"Azaion Annotator - {mediaInfo.Name}";
-        mainWindow.BlinkHelp(HelpTexts.HelpTextsDict[HelpTextEnum.PauseForAnnotations]);
-        mediaPlayer.Play(new Media(libVLC, mediaInfo.Path));
+        _formState.CurrentMedia = mediaInfo;
+        _mediaPlayer.Stop();
+        _mainWindow.Title = $"Azaion Annotator - {mediaInfo.Name}";
+        _mainWindow.BlinkHelp(HelpTexts.HelpTextsDict[HelpTextEnum.PauseForAnnotations]);
+        _mediaPlayer.Play(new Media(_libVLC, mediaInfo.Path));
     }
 
     private async Task SaveAnnotations()
     {
-        if (formState.CurrentMedia == null)
+        if (_formState.CurrentMedia == null)
             return;
 
-        var time = TimeSpan.FromMilliseconds(mediaPlayer.Time);
-        var fName = formState.GetTimeName(time);
+        var time = TimeSpan.FromMilliseconds(_mediaPlayer.Time);
+        var fName = _formState.GetTimeName(time);
 
-        var currentAnns = mainWindow.Editor.CurrentAnns
-            .Select(x => new YoloLabel(x.Info, mainWindow.Editor.RenderSize, formState.CurrentVideoSize))
+        var currentAnns = _mainWindow.Editor.CurrentAnns
+            .Select(x => new YoloLabel(x.Info, _mainWindow.Editor.RenderSize, _formState.CurrentVideoSize))
             .ToList();
         var labels = string.Join(Environment.NewLine, currentAnns.Select(x => x.ToString()));
 
-        if (!Directory.Exists(config.LabelsDirectory))
-            Directory.CreateDirectory(config.LabelsDirectory);
-        if (!Directory.Exists(config.ImagesDirectory))
-            Directory.CreateDirectory(config.ImagesDirectory);
-        if (!Directory.Exists(config.ResultsDirectory))
-            Directory.CreateDirectory(config.ResultsDirectory);
+        if (!Directory.Exists(_config.LabelsDirectory))
+            Directory.CreateDirectory(_config.LabelsDirectory);
+        if (!Directory.Exists(_config.ImagesDirectory))
+            Directory.CreateDirectory(_config.ImagesDirectory);
+        if (!Directory.Exists(_config.ResultsDirectory))
+            Directory.CreateDirectory(_config.ResultsDirectory);
 
-        await File.WriteAllTextAsync(Path.Combine(config.LabelsDirectory, $"{fName}.txt"), labels);
-        var resultHeight = (uint)Math.Round(RESULT_WIDTH / formState.CurrentVideoSize.Width * formState.CurrentVideoSize.Height);
+        await File.WriteAllTextAsync(Path.Combine(_config.LabelsDirectory, $"{fName}.txt"), labels);
+        var resultHeight = (uint)Math.Round(RESULT_WIDTH / _formState.CurrentVideoSize.Width * _formState.CurrentVideoSize.Height);
 
-        await mainWindow.AddAnnotation(time, currentAnns);
+        await _mainWindow.AddAnnotation(time, currentAnns);
 
-        formState.CurrentMedia.HasAnnotations = mainWindow.Annotations.Count != 0;
-        mainWindow.LvFiles.Items.Refresh();
+        _formState.CurrentMedia.HasAnnotations = _mainWindow.Annotations.Count != 0;
+        _mainWindow.LvFiles.Items.Refresh();
 
-        var isVideo = formState.CurrentMedia.MediaType == MediaTypes.Video;
-        var destinationPath = Path.Combine(config.ImagesDirectory, $"{fName}{(isVideo ? ".jpg" : Path.GetExtension(formState.CurrentMedia.Path))}");
+        var isVideo = _formState.CurrentMedia.MediaType == MediaTypes.Video;
+        var destinationPath = Path.Combine(_config.ImagesDirectory, $"{fName}{(isVideo ? ".jpg" : Path.GetExtension(_formState.CurrentMedia.Path))}");
 
-        mainWindow.Editor.RemoveAllAnns();
+        _mainWindow.Editor.RemoveAllAnns();
         if (isVideo)
         {
-            mediaPlayer.TakeSnapshot(0, destinationPath, RESULT_WIDTH, resultHeight);
-            mediaPlayer.Play();
+            _mediaPlayer.TakeSnapshot(0, destinationPath, RESULT_WIDTH, resultHeight);
+            _mediaPlayer.Play();
         }
         else
         {
-            File.Copy(formState.CurrentMedia.Path, destinationPath, overwrite: true);
+            File.Copy(_formState.CurrentMedia.Path, destinationPath, overwrite: true);
             await NextMedia();
         }
     }
diff --git a/Azaion.Annotator/config.json b/Azaion.Annotator/config.json
index 8f6c036..8858c13 100644
--- a/Azaion.Annotator/config.json
+++ b/Azaion.Annotator/config.json
@@ -3,60 +3,25 @@
   "LabelsDirectory": "E:\\labels",
   "ImagesDirectory": "E:\\images",
   "ResultsDirectory": "E:\\results",
+  "ThumbnailsDirectory": "E:\\thumbnails",
   "AnnotationClasses": [
-    {
-      "Id": 0,
-      "Name": "Броньована техніка",
-      "Color": "#40FF0000"
-    },
-    {
-      "Id": 1,
-      "Name": "Вантажівка",
-      "Color": "#4000FF00"
-    },
-    {
-      "Id": 2,
-      "Name": "Машина легкова",
-      "Color": "#400000FF"
-    },
-    {
-      "Id": 3,
-      "Name": "Артилерія",
-      "Color": "#40FFFF00"
-    },
-    {
-      "Id": 4,
-      "Name": "Тінь від техніки",
-      "Color": "#40FF00FF"
-    },
-    {
-      "Id": 5,
-      "Name": "Окопи",
-      "Color": "#4000FFFF"
-    },
-    {
-      "Id": 6,
-      "Name": "Військовий",
-      "Color": "#40000000"
-    },
-    {
-      "Id": 7,
-      "Name": "Накати",
-      "Color": "#40800000"
-    },
-    {
-      "Id": 8,
-      "Name": "Танк з захистом",
-      "Color": "#40008000"
-    },
-    {
-      "Id": 9,
-      "Name": "Дим",
-      "Color": "#40000080"
-    }
+    { "Id": 0, "Name": "Броньована техніка", "Color": "#40FF0000" },
+    { "Id": 1, "Name": "Вантажівка", "Color": "#4000FF00" },
+    { "Id": 2, "Name": "Машина легкова", "Color": "#400000FF" },
+    { "Id": 3, "Name": "Артилерія", "Color": "#40FFFF00" },
+    { "Id": 4, "Name": "Тінь від техніки", "Color": "#40FF00FF" },
+    { "Id": 5, "Name": "Окопи", "Color": "#4000FFFF" },
+    { "Id": 6, "Name": "Військовий", "Color": "#40000000" },
+    { "Id": 7, "Name": "Накати", "Color": "#40800000" },
+    { "Id": 8, "Name": "Танк з захистом", "Color": "#40008000" },
+    { "Id": 9, "Name": "Дим", "Color": "#40000080" }
   ],
   "WindowSize": "1920,1080",
   "WindowLocation": "200,121",
+  "ThumbnailConfig": {
+    "Size": "480,270",
+    "Border": 10
+  },
   "FullScreen": true,
   "LeftPanelWidth": 300,
   "RightPanelWidth": 300,
diff --git a/анотації. довідка.txt b/анотації. довідка.txt
deleted file mode 100644
index e69de29..0000000