gallery manager WIP

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);
 }