Implemented ImgData

src/PixiEditor.DrawingApi.Core/Surface/ImageData/Image.cs

@@ -20,6 +20,11 @@ namespace PixiEditor.DrawingApi.Core.Surface.ImageData
         public Image(IntPtr objPtr) : base(objPtr)
         {
         }
+        
+        ~Image()
+        {
+            Dispose();
+        }
 
         public override void Dispose()
         {

src/PixiEditor.DrawingApi.Core/Surface/ImageData/ImgData.cs

@@ -10,6 +10,11 @@ public class ImgData : NativeObject
     public ImgData(IntPtr objPtr) : base(objPtr)
     {
     }
+    
+    ~ImgData()
+    {
+        Dispose();
+    }
 
     public override void Dispose()
     {

src/PixiEditor.DrawingApi.Skia/Implementations/SkiaImgDataImplementation.cs

@@ -22,12 +22,14 @@ namespace PixiEditor.DrawingApi.Skia.Implementations
 
         public void SaveTo(ImgData imgData, FileStream stream)
         {
-            throw new NotImplementedException();
+            SKData data = ManagedImgDataObjects[imgData.ObjectPointer];
+            data.SaveTo(stream);
         }
 
         public Stream AsStream(ImgData imgData)
         {
-            throw new NotImplementedException();
+            SKData data = ManagedImgDataObjects[imgData.ObjectPointer];
+            return data.AsStream();
         }
     }
 }