MagickImage ToWriteableBitmap();

src/PicView.Avalonia/ImageHandling/GetImage.cs

@@ -40,12 +40,7 @@ public static class GetImage
             await magickImage.ReadAsync(fileStream).ConfigureAwait(false);
         }
 
-        magickImage.Format = MagickFormat.Png;
-        await using var memoryStream = new MemoryStream();
-        await magickImage.WriteAsync(memoryStream);
-        memoryStream.Position = 0;
-
-        var bitmap = new Bitmap(memoryStream);
+        var bitmap = magickImage.ToWriteableBitmap();
         return bitmap;
     }
 
@@ -66,13 +61,7 @@ public static class GetImage
         };
 
         await magickImage.ReadAsync(new MemoryStream(base64Data), readSettings).ConfigureAwait(false);
-
-        magickImage.Format = MagickFormat.Png;
-        await using var memoryStream = new MemoryStream();
-        await magickImage.WriteAsync(memoryStream);
-        memoryStream.Position = 0;
-
-        var bitmap = new Bitmap(memoryStream);
+        var bitmap = magickImage.ToWriteableBitmap();
         magickImage.Dispose();
         return bitmap;
     }

src/PicView.Avalonia/ImageHandling/GetThumbnails.cs

@@ -77,11 +77,7 @@ public static class GetThumbnails
 
         var geometry = new MagickGeometry(0, height);
         magick.Thumbnail(geometry);
-        magick.Format = MagickFormat.Png;
-        await using var memoryStream = new MemoryStream();
-        await magick.WriteAsync(memoryStream);
-        memoryStream.Position = 0;
-        return WriteableBitmap.Decode(memoryStream);
+        return magick.ToWriteableBitmap();
     }
 }
 

src/PicView.Avalonia/ImageHandling/MagickExtensions.cs

@@ -0,0 +1,34 @@
+using System.Runtime.InteropServices;
+using Avalonia;
+using Avalonia.Media.Imaging;
+using Avalonia.Platform;
+using ImageMagick;
+
+namespace PicView.Avalonia.ImageHandling;
+
+public static class MagickExtensions
+{
+    public static unsafe WriteableBitmap ToWriteableBitmap<TQuantumType>(this IMagickImage<TQuantumType> self)
+        where TQuantumType : struct, IConvertible
+    {
+        var size = new PixelSize((int)self.Width, (int)self.Height);
+        var dpi = new Vector(96, 96);
+        var bitmap = new WriteableBitmap(size, dpi, PixelFormats.Rgba8888, AlphaFormat.Unpremul);
+
+        using var framebuffer = bitmap.Lock();
+        using var pixels = self.GetPixelsUnsafe();
+        const string mapping = "RGBA";
+
+        var destination = framebuffer.Address;
+        for (var y = 0; y < self.Height; y++)
+        {
+            var bytes = pixels.ToByteArray(0, y, self.Width, 1, mapping);
+            if (bytes != null)
+                Marshal.Copy(bytes, 0, destination, bytes.Length);
+
+            destination += framebuffer.RowBytes;
+        }
+
+        return bitmap;
+    }
+}

src/PicView.Avalonia/Views/EffectsView.axaml.cs

@@ -1,7 +1,7 @@
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
-using Avalonia.Media.Imaging;
 using ImageMagick;
+using PicView.Avalonia.ImageHandling;
 using PicView.Avalonia.Navigation;
 using PicView.Avalonia.ViewModels;
 
@@ -150,11 +150,7 @@ private async Task ApplyEffects(MainViewModel vm)
         {
             magick.Emboss();
         }
-
-        await using var memoryStream = new MemoryStream();
-        await magick.WriteAsync(memoryStream);
-        memoryStream.Position = 0;
-        var bitmap = new Bitmap(memoryStream);
+        var bitmap = magick.ToWriteableBitmap();
         vm.ImageSource = bitmap;
     }
 
@@ -166,10 +162,7 @@ private static async Task RemoveEffects(MainViewModel vm)
         magick.BackgroundColor = MagickColors.Transparent;
         magick.Settings.BackgroundColor = MagickColors.Transparent;
         magick.Settings.FillColor = MagickColors.Transparent;
-        await using var memoryStream = new MemoryStream();
-        await magick.WriteAsync(memoryStream);
-        memoryStream.Position = 0;
-        var bitmap = new Bitmap(memoryStream);
+        var bitmap = magick.ToWriteableBitmap();
         vm.ImageSource = bitmap;
     }
 }